11 - UNT Digital Library

ARMOUR RESEARCH FOUNDATION of

ILLINOIS INSTITUTE OF TECHNOLOGY Technology Center

Chicago 16, Illinois

Contract No. A T ( l l - l ) - 5 7 8

HIGH-TEMPERATURE BERYLLIUM

CORROSION PROTECTION

Phase Report Coating Development and Evaluation Phase

ARF-B229-17

September 22, 1961 to May 15, 1962

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for

Atomics International Division North Amer ican Aviation, Inc^

8900 DeSoto Avenue Canoga Parks California

Attn: T. S. Nakae

March 20, 1963

Facsimile Price $ _ ^ . - ^ ^

Microfilm Price $ / / / _ _ 3

Avai lable from the

Of f ice of Technical Services

Department of Commerce

Washington 25, D. C.

A R M O U R R E S E A R C H F O U N D A T I O N OF I L L I N O I S I N S T I T U T E OF T E C H N O L O G Y

DISCLAIMER

This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency Thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof.

DISCLAIMER Portions of this document may be illegible in electronic image products. Images are produced from the best available original document.

ARF-B229-17

HIGH-TEMPERATURE BERYLLIUM

CORROSION PROTECTION

P h a s e Repor t Coating Development and Evaluation P h a s e

HIGH-TEMPERATURE BERYLLIUM CORROSION PROTECTION

Phase Report

Coating Development and Evaluation Phase

ABSTRACT

Several coating techniques were studied with the objective of protecting beryllium neutron reflectors from oxidation during long-time ground testing of a SNAP-8 experimental reactor. The techniques include enameling, metallic slurry coating and pack-cementation conversion coating. In addition, several commercial coatings for beryllium were evaluated.

Based on screening and comparative oxidation evaluation studies an anodic coating produced by the Brush Beryllium Company was selected as being capable of affording the necessary protection.

ARMOUR RESEARCH F O U N D A T I O N OF I L L I N O I S INSTITUTE OF T E C H N O L O G Y

- ii - ARF-B229-17

TABLE OF CONTENTS

Page

1. INTRODUCTION. . . . . . . . . . . . . . 1

II. EXPERIMENTAL STUDIES . . . . . . . . . . 1

A. Initial Oxidation Evaluation P r o c e d u r e s . . . . 1 B . Pack Cementation Coatings. . . . . . . . . 2 C. Fused Alloy Coatings . . . . . . . . . . 6

1. Nicke l -Base Coatings . . . . . . . . . 8 2. S i lver-Nickel Coatings . . . . . . . . 9 3. Other Fused Coatings . . . . . . . . . 12

D. -F lame-Sprayed Oxide and Enamel Coatings . . . 13 E . Additional Coatings That Were Oxidation Tes ted . 13 F . Comparat ive Screening Evaluation . . . . . . 19 G. Emit tance of Anodized Beryl l ium . . . . . . 22

III. SUMMARY AND RECOMMENDATIONS . . . . . . 22

IV. CONTRIBUTING PERSONNEL AND LOGBOOKS . . . 26

ARMOUR RESEARCH FOUNDATION OF ILLINOIS INSTITUTE OF TECHNOLOGY

- iii - AKF-.B229-17

Table

LIST OF TABLES

Page

I Data for Exper imenta l Pack Cementation Coatings . . . 4

II Data for F lame-Sprayed and Enameled Coatings . . . 14

i n Oxidation of Chromized and Anodized Beryl l ium at 1375°F . . . . . . . . . . . . . . . . . 20

IV Oxidation of Chromized and Anodized Beryl l ium at 1450OF . . . . . . . . . . . . . . . . . 21

LIST OF ILLUSTRATIONS

F igure Page

1 Coated Beryl l ium Produced m a Chromizing Pack . . . 5

2 Oxidation Defects Developed on Chromized Beryl l ium Sample After 110 Hours at 1410°F . . . . . . . . 7

3 Silver P la ted on Beryl l ium and Fused at 1900°F for 2 Minutes in Vacuo . . . . . . . . . . . . . . 11

4 Additional Silver Pla ted on a. Fused Be + Ag Surface Followed by Nickel Plat ing. . . . . . . . . . . 11

5 Silver P l a t e 0. 08 mi l Thick, Fused and Then Nickel Pla ted . . . . . . . . . . . . . . . . . 11

6 B l i s t e r Defect In Silver + Nickel Coated Sample Exposed to Air for 334 hr at 1400°F . . . . . . . 11

7 Total Normal Emit tance of Anodized Bery l l ium a t Various T e m p e r a t u r e s and at Various Stages of P r i o r Oxidation at 1330°F in Labora to ry Air . . . . . . . 23


- iv - ARF-B229-17

HIGH-TEMPERATURE BERYLLIUM CORROSION PROTECTION

Phase Report

Coating Development and Evaluation P h a s e

I. INTRODUCTION

This is a phase r epor t on ARF Pro jec t B 229, "High T e m p e r a t u r e

Beryl l ium Corros ion Pro tec t ion , " which desc r ibes the coating development

and evaluation effort per formed during the period September 22, 1961, to

May 15, 1962. This work, per formed under Contract No. AT(11- l | - 578 , was

di rec ted toward the development of coatings for beryl l ium neutron re f lec tors

for oxidation protect ion during S8ER ground tes t ing. The re f lec tors a r e to

be protected from oxidation forSBOO hrs£ . t l300 F in an a tmosphere of helium

containing 100 ppm oxygen.

The exper imenta l p rog ram, descr ibed here in , consis ted of a coat

ing development and evaluation effort from which a coating and vendor were

selected for use on the actual ref lector p a r t s . This effort was subsequently

followed by a coating vendor qualification and acceptance test ing phase , the

r e su l t s of which appear in AMF Report B 229-16.

The coatings which were made at the Foundation were produced by

pack cementation, by metal l ic s lu r ry coatingj and by enameling. These ,

along with p l a sma- sp rayed and anodized coa.tings produced by other o rgan iza

t ions , were evaluated under oxidizing conditions designed to pe rmi t e x t r a

polation to the t ime- tempera ture-envi ronroeBt conditions anticipated during

ground test ing.

II. EXPERIMENTAL STUDIES

A. Initial Oxidation Evaluation P r o c e d u r e s

During the initial development effort on this p r o g r a m , screening

t e s t s which consisted of oxidation exposure in labora tory a i r at 1410 F or

1330 F were used as evaluation c r i t e r i a for the coated spec imens . Tes t s

were run in labora tory muffle furnaces which contained smal l holes for

ARMOUR RESEARCH F O U N D A T I O N OF I LL INOIS INSTITUTE OF T E C H N O L O G Y

.. 1 _ ARF-B229-17

thermocouple inser t ion . The furnace j were located within a hood having a

high a i r flow r a t e ; however , the a tmosphere inside the furnaces was r e l a t i ve

ly s ta t ic . The tes t specimens^ which were smal l cyl inders or sma l l c i r cu la r

or square d i sks , were placed on alumina boats or caps . The beryl l ium was

S200 grade obtained from the Brush Beryl l ium Company.

Coated spec imens were examined at approximate ly 24-hour i n t e r

va l s . The f i r s t visible evidence of oxidation was used a s a c r i t e r ion for

determining oxidation life. Initial oxidation occur red ei ther in a genera l f a s

hion or , more frequently, was highly localized and appeared as a sma l l nodular

growth of BeO on the surface ,

B . Pack Cementation Coatings

The e lements chromia.m» si l icon, titaniums and combinations of

these were applied to beryl l ium by diffusion coating using a pack cementat ion

p r o c e s s , with the objective of producing oxida t ion- res i s tan t surface com

pounds. The bery l l ides of chromium and t i tanium a r e known to r e s i s t oxida

tion at high t e m p e r a t u r e s and p resumably undergo no abnormal rapid a t tack

in the so-ca l led "pes t " region. Similar behavior JS repor ted for the s i l ic ides

of chromium and t i tanium.

In this studys smiall berylliumi specimens were packed in fine pow

der , general ly -325 mesh , of the element to be plated. The spec imens and

powder were contained in a tantalum or s ta in less s tee l boat along with a smal l

cup containing a volati le hallde sal t . The sa l ts which mere studied include

NaF, KF , NaCl, NH^Cl. KI, and Nal. The pack mix^.ure was placed inside a

sea led Inconel muffle containing argon, and heat=.d at *-empers„tures in the range

1700 to 2050 F for t imes up to 16 hou r s . Under these conditions a number

of physical and chemical reac t ions can occur ; however , the sequence of *^vents

which is des i red in o rde r to successfully produce diffa-ion coatings is as

follows:

(1) The halide sal t volat i l izes and par t ia l ly d i ssoc ia tes

so that:

(a) the free halogen may reac t with the plating

powder to form a stable volati le hal ide, or


^ 2 - ARF~B229-17

(b) the halide salt may reac t d i rec t ly with the powder;

for example, 4NaCl(g) + Ti(s) TiCl^(g) + 4Na(g)

(2) The meta l halide may reac t and be deposited on the

beryl l ium surface according to the following react ion:

TiCl^(g) + ZBefsl Ti(s) + 2BeCl2(g)

(3) The ti tanium deposited on the surface diffuses into the

bery l l ium, exposing more beryl l ium to pa r take in the

above react ion. Although the dissocia t ion p r e s s u r e s

a r e known and equil ibrium constants can be d e t e r

mined for most of the reac t ions involved, this p r o c e s s

i s s t rongly influenced by unknown factors such a s the

diffusion ra t e and activity of beryl l ium in the surface

l a y e r s , concentrat ion of the react ing species j and

actual pack design. For these r easons coating expe r i -

ments were la rge ly empi r i ca l in which pack design,

pack composit ion, act ivator specieS; t e m p e r a t u r e , and

t ime were var ied to produce the des i r ed coat ings.

Data for the ea r ly coating exper iments appear in Table I. In mos t

of the ear ly coating runs a pack design, in which the plating e lement and

act ivator were blended, was used. This design was subsequently rep laced

with a "d ry -pack" in which the coating e lement and act ivator a r e physical ly

separa ted and in terac t ion can only occur through vapor t r anspo r t . Resul t s

were be t te r for this design. In the exper iments conducted at the higher t e m

p e r a t u r e s , excess ive quanti t ies of beryl l ium were lost from the spec imens .

In runs made at 1950 F and above, 3 to 4 mils of beryl l ium were lost from

the surface of 1 in. dia. x 0. 10 in. thick spec imens . At lower temiperatures

a sma l l e r l o s s , and in some cases a slight i n c r e a s e , in thickness was noted.

The thickness d e c r e a s e which was observed may have been due to beryl l ium

volati l ization, although this appears unlikely. Al ternat ively , it may have

been due to excess ive formation, and volati l ization of bery l l ium hal ides or

to the growth of thick beryl l ide l ayers which spalled during cooling. A photo

graph which shows such a layered composite spalled from a bery l l ium spec i

men when removed from the pack may be seen in F igure 1. This spec imen


- 3 - ARF.B229-17

TABLE I

DATA FOE EXPERIMENTAL PACK CEMENTATION COATINGS

R u n No.

IS 2S 3S 4S I C 2C 3C 4C I T I T C I S l C 3S1C I T C I C

K N I C 5C I C I S 2C1S 3C1S f.C 7C 8C 9C IOC l i e 12G 13C

Coa t ing B a s e

B e B e B e B e B e B e B e B e B e B e

S i l i con ized B e S i l i c o n i z e d B e T i t a n i u m + Chrom.t,am ©n B e E e d u c e d NiO o a B»̂

B e C h r o m i z e d B e C h r o m i z e d B<^ C h r o m i s ^ d B e

B e B e B e B e B e B e B e B e

C o a t i n g E l e m e n t

Si Si Si Si C r C r C r C r T i T i + C r C r C r C r

Cr C r C r C r C r Cr C r C r C r C r C r C r C r

A c t i v a t o r (% of C h a r g e )

5%NaF 6%NaF

lOfoNaF 10%NH4Cl lOfoNaF 10%NaF lOfoNaF

5%NH4C1 10%NaF 10%NaF 10%K.^F lOfflNaF lOfflNaF

iO%NaF., lOftNaF-^' lOfoNitF IOfflN*F 10%NaF lOfeNsI 30%Na3 10%KF 10%NaCl 10%KF 20%KF 20%KF 20%CrCl3

A t m o s p h e r e

A r g o n A r g o n V a c . A r g o n V - x . V a c . V a c . A r g o n V a c . V a c . V a c . " / a C V a c .

If- -

A r g o n V a c , V a ^ . V a c , A r g o n Asgon. A r g o n A r g o n A r g o n A r g o n A r g o n A r g o n

T e m p e r a t u r e (°F)

1920 2050 2000 WOO 1-150 2010 1900 1900 1900 1990 1920 1920 1920

1900 1950 2020 2020 2020 1850 1850 1825 1850 1950 1800 1750 1750

T i m e fhr)

2 1.2 6 4 3

14.5 15

6 3 3

16 Id 16

15 16 15 15 15 U 16 14 16 16 16 16 16

Dry pack^

No. 22796 Mag. 4

1 ~ Coated beryllium produced IB a chromiziag pack. Excess chxoresium powder is bonded t© the beryllide layer which has broken a-way from the base iBetal.

- 5 - ARF-B229~17

was coated in a chromium packs and excess chromium powder may be seen

bonded to the beryl l ide layer which has broken away from the subs t r a t e . X-

ray diffraction ana lys is of the beryl l ide layer indicates a predominance of

CrBe^ . No other beryl l ide was detected. Elect ron diffraction ana lys is of

the ba se meta l surface indicates that Cr-Be^ may be p re sen t t he re a l s o . How-

evers it appea r s m o r e likely that the p r i m a r y consti tuent in this layer should

be CrBej2- Unfortunately, the re is insufficient s t r uc tu r a l infornnation for

this compound to identify i ts ex is tence . Numerous a t t empts were made to

minimize diffusional growth during the chromizing p r o c e s s so that the lower

beryl l ide could be re ta ined a s an adherent l ayer . Coating cycles operated at

the lowest reasonable t e m p e r a t u r e for shor t t imes produced coating l aye r s of

inc reased th ickness ; however, they were not uniform. F a r t h e r work in this

a r e a was not pursued .

Oxidation screening t es t s were ran on mos t of the pack-cementa t ion

coat ings. The samples which displayed the bes't oxidation r e s i s t ance were

t i tanized beryl l ium produced in run IT and the chromi.-ed samples produced

in runs 12C and 13C. Of these , the samples from run 13C, in which anhy

drous C r C l , was used a s the halide source , appeared slightly super ior based

on screening tes t r e s u l t s . These samples withstood oxidation for 110 and

400 hours at 1410 and 1330 F , respect ive ly , in labora tory a i r , p r io r to

fa i lure . The fai lure of the coating was localized resul t ing in sma l l nodular

BeO growths on the sur face . Microexaminat ion of the spec imens in these

regions indicate that the beryl l ium had been in tergrani i lar ly a t tacked. This

may be seen in F igure 2.

C, Fused Alloy Coatings

P rep l aced metal l ic coatings fwied by typical furnace b raz ing t ech

niques may provide re l iable oxfdat ion-res is tant coalings*. In pr inc ip le , this

p rocedure is ex t remely s imple , and it has been shown to be successful in

protecting var ious other ba se m e t a l s . With beryll iums the tenacious BeO film

in te r fe res with good wettabil i ty. Improvement in wetting may be achieved by

var ious reac t ive addit ives to the fased alloy, but c a r e mus t be exe rc i sed in

alloy select ion since beryl l ium phase equil ibr ia a r e cha rac t e r i zed by fo rma

tion of in te rmeta l l i c compounds and low-melt ing eu tec t ics . An alloy


6 -.ABF-B229-17

.^,s;

• c ••••

Neg. No. 22299 Fig, 2 (a)

' : • • • • - = '••• "• •

X 50

Oxidation defects dereloped ©n chromiaed beryllium sample after 110 howrs at 1410®F.

; • .

vh

Neg. No. 2229« X 250

Fig. 2(b)

Emlaried iriew of defect which appear* in Figure 2 (a), Viewed under polarized light.

„ 7 „ ABF~BZ29-17

composit ion might be developed that provides : (1) wetting of beryl l iums (2)

oxidation r e s i s t ance to at leas t 1400 F , (3) absence of low melt ing phase s ,

and (4) long- t ime stabil i ty without adve r se interdiffusion. Because of the

difficulty of meeting these objectives within the t ime l imitat ions of the project ,

a cons iderable port ion of the effort was d i rec ted to two- layer coatings a l so .

Ea r ly work on the production of meta l l ic s l u r r y coatings was d i rec t

ed mainly toward the use of oxida t ion-res is tan t n icke l -base braz ing a l loys .

Suitably wetting beryl l ium with these m a t e r i a l s to produce an adherent coating

was a problem. It was shown that Ag-base and Ti-containing al loys show

be t te r wetting capabil i ty. Accordingly, al loys containing ti tanium have been

fused to berylliumi. Silver is one of the few meta l s that does not form an

in te rmeta l l i c compound with bery l l ium, and excellent wetting of bery l l ium by

molten s i lver has been demons t ra ted . However, s i lver will probably t r a n s

port oxygen readi ly at elevated t e m p e r a t u r e s so that an ox ida t ion- res i s tan t

outer layer such as nickel is requi red .

1. Nickel -Base Coatings

The n icke l -base s l u r r y coatings were c o m m e r c i a l b raz ing alloys

such a s Nic robraz 50 (Ni-13 w/o Cr -10 w/o P | and J-8100 (Ni-19 w/o C r -

10 w/o Si). In o rde r to minimize the formation of nickel bery l l ide , which is

the equil ibrium product , the fusion t imes were l imited to 2-5 minutes . As

anticipated, considerable difficulty was encountered m wetting the beryl l ium

subs t r a t e . Coatings of Nic robraz 50, Nicrobra.z 50 + 1 w/o germaniums and

Nicrobraz 50 with a germanium under layer were examined since previous

work at the Foundation had shown that germanium improves the wetting of

beryl l ium by molten s i lve r . A f luor ide-base flux was a lso t r i ed . Furnace

a tmospheres were vacuum^ hydrogen, or iner t gas . Usual gas purification

t r a in s including hot titanium sponge and liquid ni trogen cold t r aps were e m

ployed.

None of the r e su l t s were judged successful . The coatings frequent

ly spalled from the beryl l ium on cooling, and in no case was the bond between

the coating and the subs t ra te adequate. The use of J-8100 with a fusion t e m

p e r a t u r e of 2150 F r a the r than 1800 F for Nic robraz 50 did not r e su l t in any

improvemert; .


- 8 - ARF-B229-17

2. S i lver -Nicke l Coatings

The choice of s i lver and nickel a s a two- layer coating was based on

a careful analys is of the Be-Ag-Ni phase equi l ibr ia . It is known that s i lver

and nickel a r e re la t ively immisc ib le . During elevated t e m p e r a t u r e s e r v i c e ,

cons iderable inter diffusion between beryl l ium and its coating may be expected.

Beryl l ium phase equi l ibr ia a r e cha rac t e r i zed by low -melting eu tec t i cs . F o r

example , gold might be a candidate as a component of the coating, but the

addition of 1 w/o beryl l ium lowers the melt ing point of gold from 1945 to

1075 F . In the Ag-Be systems the lowest melt ing t e m p e r a t u r e is 1610 F .

Init ial exper iments utilized a s i lver layer about 1 mi l thick. During

the p rog ram the allowable s i lver thickness was reduced to 0. 1 mi l because of

neutron capture cons idera t ions .

A thin continuous layer of s i lver was produced by ei ther s l u r r y coat

ing or e lect ropla t ing. To provide a suitable binder for the s l u r r y coatings

without contaminating the bery l l ium the candidate b inders- -collodion, s t ea r i c

acid + C C l . , and a p rop r i e t a ry binder + CCl^ - -were placed on bery l l ium

samples and heated in vacuum at t e inpe ra tu res between 500 and 900 F . Only

the s t ea r i c acid + CCl^ resu l ted in no discolorat ion of the bery l l ium, and this

was employed for subsequent coating.

Elect ropla t ing general ly produced a m o r e uniform layer of s i lver

and improved oxidation protect ion. Excel lent plating was readi ly achieved in

a potass ium cyanide bath. A cur ren t density of 2 asf for approximate ly 20

minutes produced a 0. 1 mi l l ayer . Successful plating in 1/4 inch d iamete r

holes was accompl ished . The e lec t r i ca l contacts were moved s eve ra l t imes

to avoid poss ib le defects at the contact points . The s i lver th ickness was

m e a s u r e d at the 1 mi l level and moni tored at the 0. 1 mi l level by weight in

c r e a s e s during plating. An HCl dip is a good tes t for the p r e s e n c e of b e r y l

lium at the surface s ince beryl l ium act ively r e a c t s with HCl but s i lver does

not r eac t . This t es t showed that the 1 inil s i lver plated speci inens were c o m

pletely coated, but the 0. 1 miil layer was not continuous. Visual examinat ion

confirmed these findings.


. 9 - ARF-B229-17

The s i lver coating was fused by heating to 1900° or 2000°F for 2

to 5 minutes in vacuum or iner t gas . Silver readi ly wets bery l l ium, and the

a t tack was often so s eve re that a two-phase . Be + Ag surface layer formed.

The penetrat ion of the fused s i lver into beryl l ium is shown in F igure 3. A

spec imen with a 1-mil fused s i lver surface layer was exposed to s ta t ic a i r a t

1400 F for s eve ra l days . Whereas improvement over uncoated bery l l ium

was observed (as expected), the coating did not offer potential for long- t ime

exposure .

The spec imens with a fused s i lver coating were e lect ropla ted in a

watts nickel bath at 150 F . A cu r ren t density of 50 a m p / s q ft produced a 5

mi l deposit in 2 h o u r s . Improved r e su l t s were obtained by e lect ropla t ing

s i lver over the fused s i lver surface layer before e lectroplat ing nickel (F igure

4). Reliabil i ty of the final coating was poore r with the 0, 1 mi l s i lver coat ings .

After the 1900 F fusion t r ea tmen t , a dist inct s i lver layer was genera l ly not

observed with the 0. 1 miil coating (F igure 5), although electroplat ing of nickel

was m o r e successful over this subs t ra te than d i rec t ly on unalloyed be ry l l ium.

About ten s i lve r -n icke l coated samples were exposed to s ta t ic a i r

a t 1400 F for t imes up to 334 hou r s . Upon init ial exposure , sma l l "bumps"

appeared in mos t of the coatings, but no sagnificant change was noted with

additional t ime . These bumps may be the resu l t of hydrogen or entrapped

sa l ts from the electroplat ing bath. Vacuum heat t r ea tmen t following coating

did not r e su l t in any improvement although it i s expected that these bumps

might be el iminated with additional r e s e a r c h . Even though these bumps

appeared , the nickel coating general ly maintained i t s in tegr i ty (F igure 6) and

mos t samples did not fail during the 1400 F exposure . However, m i c r o -

graphic ana lys i s revealed that apprec iable diffusion between bery l l ium and

s i lver had occu r r ed during exposure and c r acks frequently formed between

the nickel coating and the beryl l ium subs t r a t e . There fo re , the s i l ve r -n i cke l

coating gave considerable oxidation protection^ but the s t ruc tu r a l instabil i ty

may not allow re l iab le protect ion with long- t ime exposure .

In an a t tempt to provide additional protect ion, an outer Nic robraz

layer was fused to the s i lve r -n icke l coating, but reac t ion between the nickel

and Nic robraz was s e v e r e . Severa l spec imens were coated with nickel


- 10 - ARF-B229-17

I - T * - —

I . ^1

r

Neg. No. 24243 X 250

Fig. 3 Silver plated on beryllisim aad fused at 1900OF for 2 miimtea in, vacuo.

Neg. No. 23365 X 25© Fig, 4

Additional silyer plated on a fased Be -I- Ag surface followed by nickel plating.

i i - . . •,

- » , « *

> ,

\ t

» %

Neg. No. 23364 X 250 Fig. 5

Silver plate 0.08 mil thick, ftt»ed and tken nickel plated.

Neg. No. 23346 X 5© Fig . 6

B l i * t « defect l a tiliret + nickel eoated mmmplm expound to aix* f@r 334 hx at 1400*r.

Unetched. - 11 - AmF-B229-lT

without the silver interlayer, but the bond was not as good. In addition to electroplating, a flame-sprayed layer of NiO was reduced in hydrogen to form a dense metallic nickel coating. These nickel coatings were protective at 1400 F^ but daring thermal cycling cracking occurred at the beryllium-coating interface.

3. Other Fused Coatings

A very minor effort was directed to the development of other fused coatings. PalladiuKi and silicon were selected for alloying with the Ag-Be fused surface layer on the basis of known phase equilibria, neutron capture data, and expected oxidation behavior. The Ag-Si-Be and Ag-Pd-Be alloys were produced by electroplating silver followed by slurry coating of the other elemental powder pricr to the fusing treatment. After 2 to 5 minutes at 2050 F^ the palladium-containing specimen was not completely coated and some preferential attack of the base metal was obsei^ved. With the same thermal treatment, good wetting was achieved w .th the Ag + Si coating. No evidence of failure was observed me+allographically after exposure of this specimen to static air at 1400 F for 120 hours.

Another coating approach made use of the good wetting produced by fused alloys containing titanitiin. With thi technique, the ultimate protection would probably be the beryllide layer produced either during the fusion treatment or during service exposure. CoaHng experiments involved:

Coating Alloy (w/o)' Fusion Temperature ( F | Ti-5Be ? 150, 2200 T i -28.5Ni 1900 Ti-65Ni 2100 Ti-70Ag ?.150

All of these titanium-bearing alloys wet beryllium although Ti-S w/o Be appeared to be superior. The coated sample did not fail during a 122"hour exposure to 1400 F . Therefore, this technique may offer promise for future development.


- 12 - ARF-B229-17

D. F lame-Sprayed Oxide and Enamel Coatings

Enamel coating work was l imited most ly to application of c o m m e r

cially available and s tandardized enamel s . Special surface p repara t ion t ech

niques, which included the application of f l ame-sprayed oxides, f l ame-sprayed

Nichroine, and reduced nickel oxide subs t ra te s a s a means of improving ad

herence and avoiding interact ion between beryl l ium and the ename l s , were

studied. In addition, sur face-ac t ive consti tuents such a s TiH^ and MoO^ were

added a s b inders in an a t tempt to improve adherence .

The r e su l t s of enamel fir ings a r e repor ted in Table II. All firing

was done in an argon a tmosphere . All of the enamels that were applied

d i rec t ly to g r i t -b las ted beryl l ium lacked adherence . When the enamels were

applied over a f l ame-sprayed A1~0, or Nichrome base coat, s imi l a r r e su l t s

were obtained. In al l c a ses the enamel caused the f l ame-sprayed subs t ra te

to separa te from the base me ta l . The bes t success was obtained when enamels

were applied to a reduced NiO subs t ra te on bery l l ium. Tlê enainels , Sola-

r amie No. 5210-2-C and N. B . S . A-418, applied under these conditions show

ed general ly good adherence but flaked in small a r e a s after standing at room

t e m p e r a t u r e .

The mos t proinis ing ce ramic coating studied was BaTiO^ produced

by flame spraying d i rec t ly onto bery l l ium. Two samples., having coating

th icknesses of 2 and 4 m i l s , respect ively , were tes ted at 1410 F in labora tory

a i r under conditions which caused b a r e beryl l ium to oxidize very severe ly in

l e s s than 16 hour s . The f l ame-sprayed specimens were protect ive for 90

hour s , after which separa t ion of the coating occiarred at the meta l in ter face .

E . Additional Coatings That Were Oxidstion^ Tgsted

Severa l smal l beryl l ium cyl inders , which were coated by other

organizat ions , were supplied by Mr . T. S, Nakae of Atomics Internat ional

for oxidation tes t ing. The coated samples that were supplied a r e :

Sample Coating Composition Coating Designation or Type Vendor

A Anodized Be Nuclear Metals B Anodized Be Brush Beryl l ium Co. C P r o p r i e t a r y Atomics Internat ional D P l a sma-Sprayed Z r 0 2 Western Gear


„ 13 ^ ARF-B229-17

TABLE II

DATA FOR FLAME-SPRAYED AND ENAMELED COATINGS

Beryllium samples 1 x 1 x 0 . 1 inch, were grit-blasted on one face to prepare them for the following coatings. All firing was done in an argon atmosphere.

1. Flame-sprayed alumina FC A-11 Enameb 100 5210 frit

6 green label clay 2 Cr203

1/14 potassuim nitrite 48 HgO

Firing temperature; 1875 F, 3. 5 minutes; coating spalled from base metal.

2, Same enamel as No, 1, applied directly to beryllium.

3, Flame-sprayed alumina FCA-11 Enamel: 80 No. 7052 glass

20 Cr203 Amyl acetate - Daco saspending agents

Firing temperature: 1900°F, 10 miuates Costing was not con.tin.aoas due to thin application of enamel,

4, Same combination, as No. 3 except for heavier application of enamel. Firing temperature: 1950°F Coating parted from the beryllium when cooled.

5, Enamel coating applied directly to beryllium, 80 No, 7052 glass 20 CrÔj Amyl acetate - Duco suspending agents

Firing temperature: 1880 F--10 minate.s 1920°F»-10 minutes

Coating did not adhere to metal.

6, Flame sprayed alumina FCA-11 Enamel coating No, 7052 glass

Amyl acetate - Duco suspending agents Firing temperature: 1875 F - -3 -1 /2 minutes Coating parted from beryllium while sample was cooling


_ 14 . ARF-B229-17

http://con.tin.aoas

TABLE iJ (Cont.)

Enamel coating applied d i rec t ly to beryl l ium No. 7052 g lass

Amyl ace ta te - Duco susp^nd-«ng agents

Resul ts same a s No, 6. Coating par ted from sample .

F l am6"sp rayed alumina FCA- 11 No, 0010 g lass

Amyl ace ta te - Duco saspending agents F i r ing t empe ra tu r e - 1875°F= 3-1 /2 minutes A glossy coating w«*3 formed but after cooling, the coating par ted from the me ta l

Enamel applied d i rec t ly to beryl l ium Nc. 0010 glass

Same suspending ageii\^ -ind f>ing cond ''c^^ Resul t s s ame a s for No, 8

F C A - 5 1 , a pouderfcd t-hrom-'um-ii 'ke'" alloy appii^^d by flame spraying. F l a m e sprayed alumina^ F C A - 1 1 , No. 7052 glaas suspended in amyl d.i-e*-at^ and Daro cement . F i r ing t empe ra tu r e 1875 F°"3- - j /2 minutes . A fairly solid mal l t i s * Kg \%e»s foimt-d, b j l Ihs ent i re coaling lifted from the berylL im.

F C A - 5 1 , ch romiam n! :kr l alk»y. No. 7052 g lass suspended in amyl ace la te and Duco cement . F i r ing t e m p e r a t u r e 1875°F""3"i.* 2 m i m l e s . An uneven glassy % od ing formed, bat i*" d'd nc adhere to the bery l l ium,

F C A - 5 1 , chromium - a ' rke l <d.lloy. Hydride coating: 2, 3% TiH2» 2, 0% MoO^ Sf^spended in amyl ace ta te ard Duco i enr^n*. No, 0010 gl55,s«? âsp^nded ^^ '-Tiyl areJ-*^' and Duco cement . F i r ing 800°F- -15 iTi'riutP>«, +emp**r.d' *•»•? tlên r a i s ed to f i re g l a s s , 1 8 7 5 0 F " - 3 - i ; z TO t i ^ > 5 . An unp\ens ^'nt^îed cos'.T,g fcrm**^, Thr ert*r'=» coating came free from the b e r y l l | ^m,

F C A - 5 1 , '-"hrom-itm-n. "kel otllr^. Hydride coatrng same =t% Nc, 3 70 No. 7052 gl«ss 30 C r ^ O j Suspended in imyl A^^<--Ae ar.d Du.*o cement . F i r ing 800°F""15 m i - n - e i , t e m p e r a t u r e then r* sed to f i re g lass 1950°F ' -10 m > j / - s .

RESEARCH F O U N D A T I O N OF I l l l N O I S INSTITUTE OF T E C H N O L O G Y

- 15 " ARF-B229-17

TABLE II jCoiH.)

The coating flaked off in the center of the sample . The glassy coating appears to adhere to the F C A - 5 1 , but the FCA-51 alloy did not adhere to the berylljum-

F C A - 5 1 , chromium-nicke l al loy. F C A - 1 1 , f l ame-sprayed alumina „ CV-15-S-184 enamel . F i r ing t e m p e r a t u r e , 1740°F--5 minutes . A rough bubbly glassy coating was formed. However, the ent i re coating came off in one piece at the beryl l iujm/FCA-51 interface .

FCA-5I5 chromium "nickel alloy. F C A - 1 1 , f l ame-sprayed a lumina. No. 6600 enamel . F i r i ng t e m p e r a t u r e , 1740°F- -5 minutes . A glassy mottled surface obtained that probably would smooth out at a higher firing t e m p e r a t u r e , but the en t i re coating separa ted from the bery l l ium.

Nickel oxide flame sprayed on one face of sample than reduced in a hydrogen a tmosphere at 1200°F. No. 5210-2-C enamel applied and fjred at 1 8 7 5 ° F - - 3 - l / 2 minutes . A good adher ing coating was obtained although t h e r e w e r e sma l l b a r e spots where the enamel did not flom*. A second enamel coat ing will be applied a.t slightly higher firing t e m p e r a t u r e s and a longer firing t ime will be used.

Nickel oxide coating hydrogen reduced at 1200 F a s in No. 7. N. B . S . A-418 enamel fired at 1850°F- -3 minu tes . This sample a l so showed good adherence and had about the s ame appearance as sample No. 16. A second enamel coating will be applied and ref i red .

Nickel oxide coating, hydrogen reduced at 1200 F . F C A - 1 1 , flame sprayed a lumina, 70 No. 7052 glass 30 ^ ^ 2 ^ 3 Suspended in amyl ace ta te and Duco cement . F i r ing t e m p e r a t u r e , 1950°F-"8 minutes . A rough s in tered coating obtained. Some smal l specks flaked away.

RESEARCH F O U N D A T I O N OF I LL INOIS INSTITUTE OF T E C H N O L O G Y

- 16 - ARF-B229-17

Sample Coating Composition Coating Designation or Type Vendor

E P la sma-Sprayed C a Z r O j Wes te rn Gear F P l a sma-Sprayed AlgO^ Wes te rn Gear G P la sma-Sprayed BeO Wes te rn Gear

The samples were tes ted in labora tory a i r a t t e m p e r a t u r e s which

var ied between 1403 to 1417 F . Weight change data were r ecorded for each

sample and for an uncoated beryl l ium control spec imen. The r e su l t s a r e a s

follows:

2 Cumulative Weight Change (mg/cro ) Sample i T h i ^ T t o " T 9 h F ~ ^ r 6 : ^ h r ^-pTg-SF- i i o ,5h r Control 44

A 1.14 2.96 B -1 .24 -1 .84 -1 ,84 - 2 . 0 8 - 2 . 2 3 C - 1 . 2 1 -1 .75 - 1 . 9 1 -2 .10 -1 .97 D 10.5 E 9. 1 F -1 .24 G 7 ,6

Oxidation t e s t s were discontinued in ea rh case after the longest t ime

indicated in the above table . The sprayed o-^-lde r.oatings, samples D through

G, showed l i t t le protect ive capabil i tv. Sample F apparent ly provided some

protect ion during the initial l6-hoitir exposure b»it c racked and then flaked from

the subs t ra te during coolang from the tes t t e m p e r a t u r e .

Sample A was oxida^îon res-»stant fo-»" some t ime bat failed by genera l

de te r iora t ion at edges and at the epds of the spe-i '•men after 59 h o u r s . Samples

B and C withstood oxidation for 93, 5 hours before sLight evidence of d e t e r i o r a

tion was noted. The de te r iora t ion was in the form of a sma l l nodule of BeO

which had broken through the coating. Continued exposure^ to 110, 5 hou r s ,

caused a slight i n c r e a s e in the number and s ize of the nodules. The defects

on sample B were at the ends of the cylinder at points that were apparent ly

used in making e lec t r i ca l contact during the anodizing p r o c e s s . Sample C

showed fai lure on the cyl indr ical surface .

A further compar i son of the coatings r ep resen ted by samples B and

C was made by oxidat ion-test ing additional coated samples at 1330 F in


„ 17 _ AKF-B229-17

l abora tory a i r . F a i l u r e was noted on the Atomics Internat ional spec imen after 280 hours and after 380 hours for the Brush Beryl l ium Co. anodized

sample . The fa i lures were s imi la r to those noted at the higher t e m p e r a t u r e .

F . Comparat ive Screening Evaluation

On F e b r u a r y 5, 1962, the most p romis ing coatings which had been

found were subjected to a cotBparative oxidation screening tes t evaluation.

These t e s t s were per formed in dry a rgon containing 1% a i r a t 1325 F . The

coated samples that were evaluated a r e :

(1) Chromized bery l l ium

(2) Titanized beryl l ium

(3) Chromized berylliumi with an 8 mi l e lec t ropla ted

nickel over lay

(4) Anodized beryl l ium (Brush Beryl l ium Co.)

(5) Sample H (Atomics International)

After 405 hours sample H showed evidence of fai lure s imi l a r to

that observed when tes t ing in labora tory a i r a t th is t e m p e r a t u r e . The nickel

over lay on chromized beryl l ium lost adherence and broke away frona the base

meta l a t two c o r n e r s . The sample beneath the nickel , however , showed no

evidence of fa i lure . The chromiized, t i taniaed, and anodized samples a l so

showed no evidence of fai lure after 405 hour s .

Based on these tes t r e su l t s it was dec ided- -a t a meet ing held a t

the Foundation on Apr i l 3-4, 1962 involving M e s s r s . T. S. Nakae^ K. W.

Hinze, G. Erwin J r . , and J . W. Ramsey of Atomics Internat ional and J . J .

Rausch and R. J . Van Thyne of the Foundat ion-- to proceed with a s e r i e s of

exper iments designed to de te rmine whether the anodized or chromized coat

ing was supe r io r . Specimens of chromized and anodized samples were t e s t

ed a t 1375 and 1450 F in labora tory a i r , dry a i r , a r g o n - 1 v /o a i r and a rgon -

0.05 v /o a i r . The spec imens that were tes ted in the dry gases were contained

in Vycor bulbs through which the appropr ia te a tmosphe re was slowly purged.

The coated tes t spec imens were general ly cy l inders , 3/4 in, dia, x 1 in. longs

some of which had 1/4 in. dia, holes running the length of the cyl indr ical ax i s .

The compatibil i ty of the coated samples with s ta in less s tee l was evaluated by


^ 18 - ARF-B229-17

bolting washe r s to the samples containing ho les . Type 304 s ta in less s tee l

bolts and w a s h e r s , which had been preoxidized at 1200 F for 1 hour , were

used.

Tes t r e su l t s at 1375 and 1450 F a r e summar i zed in Table III and

IV, respec t ive ly . At the lower temiperature the chromized s ample s , exposed

in a i r , al l failed within 418 hou r s . Fa i lu re was by general oxidation; that i s ,

by the formation of smal l growths of BeO over the ent i re surface of the s a m

p l e s . The behavior is s imi la r to the breakaway oxidation which occu r s in

uncoated bery l l ium, although the t ime requ i red for the inception of breakaway

is somewhat r e t a rded in the chromized s ample s . This indicates that the coat

ing on these samples is uniform, but quite thin.

Anodized samples tes ted under these conditions, a t 1375 F , show

life t imes of 362 to somewhat g rea t e r than 592 hours before the f i r s t evidence

of fai lure becomes apparent . Fa i lu r e of these samples is highly local ized,

being confined general ly to the points at which contact was made dar ing anodiz

ing. On specimens containing holes along the cylindrical axis^ fai lure was

observed on the outside of the cyl indrical surface when anodic contact was

made . These spec imens , which were run only in dry a i r , contained s ta in less

s teel bolts with washe r s at the ends. Upon removing the bolts and w a s h e r s ,

it was apparent that re la t ively l i t t le oxidation had occur red where the s ta in

l e s s s tee l was in forced contact with b e r y l l i u m - - t h a t i s , the anodized s u r

face re ta ined much of i ts or iginal black color slight oxidation of the anodized

surface was apparent within the hole.

The obvious super ior i ty of the anodized coating is a lso shown on

the bas i s of oxidation test ing at 1450 F . In l abora tory a i r , a chromized

beryl l ium sample was completely oxidized after 128 hou r s . An anodized

sample was oxidized in the hole and at one point on the surface where e l e c t r i

ca l contact was made during anodizing. Fa i lu r e within the hole had p r o g r e s s e d

to the point where oxidation had formed enough BeO in this region to cause the

specimen to c rack . The outer surface of the specimen was unattacked except

for the anodic contact point.


- 19 - ARF-B229-17

TABLE III

OXIDATION O F CHROMIZED AND ANODIZED BERYLLIUM AT 1375°F

TimCj in hours , a t which f i r s t evidence of fai lure

Atmosphere

Labora to ry Air

Dried Air

Argon-1% Air

Sample Type

Chromized Anodized

Chromized^ Chromized'^ Chromized Anodized*

3 ^

Anodized

Anodized

Chromized Anodized

was appa

338 362

478.5 478.5 478.5 568

568

592

568 840

R e m a r k s

Argon-0 . 05%Air Chromized Anodized

568 840

General oxidation over ent i re surface . Slight oxidation at contact points .

Very s eve re general oxidation. Slight general oxidation. Slight general oxidation. Slight oxidation at contact points on outer surface . Slight oxidation at contact points on outer sur face . No visible defects.

No visible de fec t s - - t es t stopped. Slight oxidation at contact points on end.

No visible de fec t s - - t e s t stopped. Slight oxidation at contact points on end.

These specimens contained preoxidized s ta in less steel bolts and w a s h e r s .

TABLE IV

OXIDATION OF CHKOMIZED AND ANODIZED BEKYLLIUM AT 1450°F

Atmosphere Sample Type

Timej in hours , at which f i r s t evidence of fai lure

was apparent Remarks

Labora to ry Air

Dried Air

Argon-1% Air

Anodized

Chroinized

Anodized

Anodized

Anodized Chromized Chromized Chromized

Chromized^ /..aodized

Argon-0 , 05% Air Chromized Anodized

128

128

246

246

152 145 145 145

287 270

287 270

Failad inside hole and at a contact point on outer surface . Sample was completely oxidized.

Slight evidence of failure near contact points . Slight evidence of failure near contact points . Fa.ilu.re at contact point on end. Very severe general fa i lure . Very seve re general fa i lure . Very severe general fa i lure .

No evidence of fa i lure . No evidence of fa i lure .

No evidence of fa i lure . No evidence of fai lure.

This spec imen contained a preoxidized s ta in less s teel bolt and washer .

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Three anodized samples were exposed in d ry a i r at MSO^^F. E l e c

t r i c a l contact during anodizing was made on the ends of these s a m p l e s .

Fa i lu r e occur red in this region after 152 hours on one sample and at 246 hours

on the o the r s . Chromized beryl l ium was severe ly oxidized after 145 h o u r s .

The super io r i ty of anodized bery l l ium is apparen t from these tes t

r e s u l t s . Near ly a l l of the fa i lures that occur red in the anodized spec imens

were highly localized and a r e apparent ly assoc ia ted with p rocess ing difficul

t i e s . The life of the coatings in regions other than at the defects is cons ide r

ably g rea te r than the fai lure l ifet imes repor ted in Tables III and IV.

G. Emit tance of Anodazed Beryl l ium

The total no rmal emit tance of anodized bery l l ium spec imens was

determined at 400 , 800 s and 1200 F , The technique used in making these

m e a s u r e m e n t s has been descr ibed in a previous ARF repor t .

Measuremen t s were made on a spec imen in the a s -coa ted conditions

and on spec imens which were pre-oxidized at 1330 F for 48 hours and for 140

hou r s . The enîttance valaes a r e shown in F igure 7. Although considerable

var ia t ion exis ts a t lower t e m p e r a t u r e s , al l of the emit tance values converge

to 0 . 7 0 - 0 . 74, a t 1 2 0 o V .

III. SUMMARY AND RECOMMENDATIONS

The objective of this p rogram was to develop coatings to p ro tec t

beryl l ium neutron re f lec tors from oxidation during S8ER ground tes t ing. The

protect ion requ i red is for 3800 hours at 1300 F in an a tmosphere of He-100

ppm oxygen.

In this p r o g r a m , th ree well es tabl ished coating techniques^ which

appeared to offer the mos t p r o m i s e in accomplishing our objective, were

studied. A p r o g r a m of this type, or iented toward the study of coating tech

niques r a the r than development of actual coating systems^ was necess i ta ted

by the 2 1/2 month t ime l imit available for development work. The tech

niques investigated were pack-cementa t ion convers ion coating, meta l l i c

s l u r r y coating, and enameling.

Ôlson, O. H. , WAD"c~fR~6l-2227 Par ' t III, Apr i l I960.

ARMOUR RESEARCH F O U N D A T I O N OF I l l l N O I S INSTITUTE OP T E C H N O L O G Y

- 22 - ARF-B229-17

0.4

0.3

0.2

0. 1

0.0

D ^

^ ^

A& R£CiEIS£n

OXIDiaED

OXtPIZ ED

AT 133(

AT 133C ̂ F ,

M^'MS,

14C HRS.

400 800 1200

TEMPERATURE {°F]

FIG. 7 - TOTAL NORMAL EMITTANCE OF ANODIZED BERYLLIUM AT VARIOUS TEMPERATURES AND AT VARIOUS STAGES OF PKIOR OXIDATION AT 1330«^F IN LABOBATORY AIR.

RESEARCH F O U N D A T I O N OF I l L I N O i S INSTITUTE OF T E C H N O L O G Y

- 23 - ARF-B229-17

Pack cementation was used to produce chromium and titanium beryllides, mixtures of these, and mixtures of the beryllides with silicides. The coatings produced consisted of only a solid solution of beryllium containing the coating species or at most a very thin layer of the highest beryllide formed in the system. Beryllide layers that grew to appreciable thicknesses were found to spall from the substrate either during growth or upon cooling from the diffusion temperature. Simple chromizing of the beryllium provided about a fivefold increase in oxidation life over uncoated beryllium at 1330°F.

Metallic slurry coatings based on nickel containing additions to lower the melting temperature, or to promote wettability, were studied. Consistently reliable wettability vas obtained in materials which contained significant quantities of t-',tanium. The titariaro, however, through diffusional interaction with the base metal, produced beryllides which spalled from the surface, taking the remainder of the coating '*ith them. The most successful coatings were produced by using an intermediate la,yer of silver to promote bonding. The thickness of silver required to consistently obtain good bonding to beryllium was found to be too thick for nurlear purposes and there was insufficient timie to develop the coating process to the point where extremely thin silver layers could be utilized.

Enamel coatings on beryllium were found to lack adherence and generally were not expansivity-matched to the base metal. Attemipts were made to overcome these deficiencies by depositing a flame-.•sprayed base coating and impregnating this with the enamel, .'in all cases, however, expansion s t resses resulted in ruptare of the bond between the flame-sprayed coating and beryllium.

Of all commercial and experimental coaling processes studied, the most successful was anodizing performed by the Brt.sh Beryllium Company. The superior performance of beryllium coated in this manner was borne out in screening and in comparative evaluation tes ts . Most coating failures that have been observed are localized and appear to be due to processing difficulties in application of the coating. The life of the coating in regions away from the defects is considerably greater than the failure lives that a re


- 24 - ARF-B229-17

reported in Tables III and IV. If the coating process can be controlled to eliminate these defects it appears reasonable to expect a service life of greater than 3000 hours at 1300 F in a He-100 ppm oxygen atmosphere. This extrapolation is based on existing data and upon the pressure-and temperature dependent oxidation behavior, determined by Dr, G. Erwin J r . of Atomics International, for uncoated beryllium^ Service life of 3000 hours under S8EK test conditions would correspond approximately to 70 hours in air at 1450 F . The validity of such an extrapolation is questionable, of course, but by allowing for an adequate safety factor it should be possible to anticipate a sale minimum service life based on high-temperature, high-oxygen partial pressure qualification tests . The test data that have been accumulated indicate a wide scatter in the time at which both localized and general failure occur in anodized test samples. Localized failures have occurred in times ranging between 42-244 hoars when tested in air at 1450 F. Similarly, general deterioration of the coating has been observed in times ranging between 42 hours to, in some cases, greater than 372 hours. If processing could be improved so that failure would occar at the longer indicated t imes, this coating should prove adequate for the proposed S8EB ground tests .

Based on our test results , therefore, it was recommended that anodizing, performed by Brush Beryllium Company, be used to protect the S8ER reflectors from oxidation daring ground testitig. Th.'s recommendation was based on the ability of Brush to improve the consistency of thier anodizing process and to demonstrate a caipabilffcy for adequately coating the intricate neutron reflector shapes. This work w^s performed, and is r e ported in ARF 2229-16.


- 25 - A1F-B229-17

IV. CONTBIBUTING PERSONNEL AND LOGBOOKS

The following personnel have contributed to the work that was

per formed on this projec t ;

J . J . Rausch - P ro j ec t Leader

R. J . Van Thyne - Met. S lu r ry Coatings

D. C. Schell - Enamel Coatings

T. Niemczyk - Technician

O. Sanders - Technician

Data for this work a r e recorded in A E F Logbooks No. C 11687,

C 11907, C 12058 and C 12219.

Respectfully submitted,

ARMOUR RESEAECH FOUNDATION OF ILLINOIS INSTITUTE OF TECHNOLOGY

iL

.NîJ^^^^^ J . iff. R a u s j

mior MeiAUrfrgtlst

^ ^ S S C - ^ ^ ^ S ^ ^ X , ^ .

R. J . VanThyne Ass i s tan t Direc tor Metals and Ce ramic s R e s e a r c h

JJR/RJVst lm

ARMOUR RESEARCH FOUNDATION OF ILLINOIS INSTITUTE OF TECHNOLOGY

.. 26 •• ARF-B229-17

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