Tool wear in Ti-6Al-4V alloy turning under mixed cryogenic ... · Sino-German Center on Sustainable Manufacturing 2014, Germany, August 3rd–International Conference on Sustainable

Sino-German Center on Sustainable Manufacturing 2014, Germany, August 3rd– 8th 2014; Prof.C.Y.Wang, GDUT

Tool Wear in Ti-6Al-4V Alloy Turning under Oils on Water Cooling Comparing with Cryogenic Air mixed with Minimal Quantity Lubrication

Prof. Chengyong Wang

Institute of Manufacturing Technology

(IMT)Guangdong University of Technology,

China

International conference on sustainable manufacturing (ICSM)

Advanced Manufacturing Technology Center AMTC, Tongji University

October 23 –October 24, 2014


GDUT

Guangdong University of Technology, GDUT

Guangdzhou



Established in 1958

Total full-time students： 47,000

Undergraduate students:43,000

Postgraduate students: 4000;

Faculty: 19

Employers: 3100

Professors: 300

Associate Professors:700;

Campus: 4

73 bachelor programs

100 master and doctoral programs

73% Engineering

R&D Fund: 3.5 Billion RMB;

Budge: 15 Billion RMB


4


Total full-time students： 4143

Undergraduate students: 3223


Employers: 153

Professors: 47


Professors: 10



Research field:

High speed machining, polishing and

lapping

Cutting tool (PVD/CVD coated / Ceramic/

Diamond)

Micro machining and Laser machining;

Machine tool design and automation

Medical surgery tool and biomechanical

design;

Low carbon manufacturing technology;

Research field:

Material processing

technology

Machine tool and automation

Robotics,Logistic and CIMEs

Design theory and methods

Automobile manufacturing

Industrial management

Director:

Prof.C.Y.Wang

International Conference on Sustainable Manufacturing, October 23th–24th, 2014; Prof.C.Y.Wang,GDUT



Professors: 5


Postgraduate students:80;

Postdoctors: 10

Advanced Cutting Tool and Ceramic Center

Research field:

High speed machining; polishing and lapping of crystal materials;

PVD/CVD/Ceramic Cutting tools;

Medical surgery tools and biomechanical design;

Low carbon manufacturing technology （using of new energy, MQL.. ). 2 μm 2 μm

TiSiNTiN

2 μm

TiAlSiN

2 μm

TiAlN

TiCrSiN

2 μm

2 μm

TiCrAlSiN

Cabide

Hardend Steel Graphite machining CGI Milling PCB Mircoholes nano-PVD cutting tools Ceramic cutting tool Surgery tools

Mould and Die Solar energy and EDM Diesel Engine (< 0.2 mm)



Introduction 1

Experiment 2

Results and discussions 3

Conclusions 4

CONTENTS



Widely used material

Excellent corrosion resistance,

Low density or high strength-to-weight radio,

Good high temperature properties.

......

Difficult to machine material

Low thermal conductivity,

Low elasticity modulus,

High chemically reactive.

......

Common machining methods

Wet cutting,

minimal quantity lubrication (MQL),

high presure cooling,

water vapor cooling,

cryogenic cooling

......

INTRODUCTION

Ti-6Al-4V



Minimum quantity lubrication (MQL)

Application

Slower heat transfer

INTRODUCTION Problems: Near dry cutting - MQL



Advantages Disavantages

Compared to LN2 cooling, the gas temperaure is not too cold to change the properties of Titanium alloys.

Energy saving technology

High equipment cost

Noise pollution

Lubricant is possible to be freezed in the MQL equipment during the mechining process.

INTRODUCTION Problems: Mixed cryogenic air and MQL - CAMQL

Lubrication + Heat transfer

Cryogenic air

MQL



INTRODUCTION New method: Oils on Water (OoW)

External OoW

(EOoW)

Internal OoW (IOoW)

Lubrication + Heat transfer

Oil

Water

AIRAir supply system

Oil filmWater



Coooling method

Equiment

(produced by DG Armorine energy-efficient and eco-friedly Tech Co.,Ltd ）

Equiment cost High Low

Noise Very loud Small

OoW CAMQL

EOoW IOoW

CAMQL IOoW EOoW

INTRODUCTION OoW vs CAMQL cooling:

Which Cutting performance is better for turning Ti-6Al-4V?

CAMQL



Introduction 1

Experiment 2


Conclusions 4

CONTENTS



EXPERIMENT

Machine tool CAK3675V CNC

lathe, China

Work piece

Ti-6Al-4V alloy

Φ50 mm×200

mm

Cutting speed (m/min) 70, 90, 110

Depth of cut (mm) 1.0

Feed rate (mm/rev) 0.25

Inserts

WNMG080412-MF5,

coated cemented carbide

Seco tools, Sweden

1. TS2500:

PVD

coating

TiAlN

2. TH1000:

CVD

coating

TiAlSiN

3. TP2500:

PVD

coating

Al2O3/TiC

2 mμ

TiAlN

a

2 mμ

TiAlSiN

b

5 mμ

Al O2 3

TiC

c

Equipment, cutting tools and cutting parameters



EXPERIMENT

Cryogenic air equipment

CAMQL

IOoW equipment

IOoW

EOoW equipment

EOoW

Produced by DG Armorine

energy-efficient and eco-friedly Tech Co.,Ltd ）

Type of oils Main

composition

Viscosity

(40℃) [cSt]

Flash point

[℃]

Lubricity Cooling ability

2000-10 Fatty alcohol 15 165 Moderate High

2000-30 Synthetic ester 30 290 High Moderate

Cooling methods



Three Spray locations:

EXPERIMENT EOoW cooling

Water supply: 150 mL/h; air: 12℃, water: 20℃

Air pressure: 0.3 MPa ; MQL supply Oil: 20 ml/h



EXPERIMENT IOoW cooling

Water supply: 1.2 L/h and 2.4 L/h; air: 30 ℃, water: 30 ℃;

Air pressure: 0.3 MPa; MQL Oil supply: 20 ml/h



Different cryogenic air temperature : -16 ℃, -26 ℃

Air pressure: 0.3 MPa; MQL supply Oil: 20 ml/h

EXPERIMENT CAMQL cooling

CAMQL



EXPERIMENT Measurement

Cutting temperature

TVS-500EX thermal infrared equipment

Cutting force

Kistler type 9257B

Cutting tool

wear

OLYMPUS SZ61 microscope

Cutting tool

wear morphology

Supra 40 SEM Element analysis

Supra 40 EDS

Surface roughness

TR110A



Introduction 1

Experiment 2

Results and

discussions 3

Conclusions 4

CONTENTS



EOoW

(rake and flank faces)

EOoW

(flank face) EOoW

(rake face)

The chip morphology of EOoWr (rake face) and EOoWrf (rake and

flank faces) is similar.

The chip morphology of EOoWf (flank face) is much shorter due to

the spraying direction of air from down to up, which makes the chip

easier to break.

RESULTS AND DISCUSSIONS 1. EOoW and IOoW

Chips- EOoW :



IOoW (1.2 L/h water)

IOoW (2.4 L/h water)

The chip morphology of IOoW (1.2L/h) and IOoW (2.4L/h) are similar.


Chips- IOoW :



22

EOoWr and EOoWrf have almost the same cutting temperature,

while EOoWf is about 80℃ higher.

IOoW with a larger amount of water has better ability to reduce the

cutting temperature.


Cutting temperature:



EOoWrf have the lowest feed force Fx, EOoWf is the second lowest.

EOoWf has the lowest main force Fz ;

IOoW (1.2 L/h water) has the lower feed force Fx, but higher main

force Fz.


Cutting force:



The surface roughness of EOoWf is the lowest, while EOoWrf is the

highest.

IOoW (1.2 L/h water) has the lower surface roughness compared to

that of IOoW (2.4 L/h water).


Surface roughness:



EOoWrf have the best ability to reduce the flank wear rate, while

EOoWf is the worst.

IOoW (1.2 L/h water) has much better ability to reduce the flank wear

rate.


Flank wear:



EOoWf has larger

chip bulk in the

rake face,

indicating severer

adhensive wear.


Rake face wear- EOoW:



IOoW (1.2 L/h ) does not has large chip bulk in the rake face,

indicating less severer adsensive wear.


Rake face wear- IOoW:



Zone A is only

absent from

EOoWrf due to

better lubrication

effect.


Flank wear- EOoW :



Zone A do not exist in flank face using IOoW (1.2 L/h) due to better

lubricating effect.


Flank wear- IOoW :



The properties of lubricants has no inflence on surface roughness

of EOoWf.

The properties of lubricants has no inflence on flank wear rate of

EOoWrf.


Effect of lubricant - EOoW :

Cutting distance (m)



Lubricant 2000-30 is better in lowering surface roughness of IOoW

(1.2 L/h water) compared to 2000-10.

Lubricant 2000-30 is better in reducing flank wear rate of IOoW (1.2

L/h) compared to 2000-10.


Effect of lubricant - IOoW :



Dry cutting Wet cutting

The chip morphology of CAMQL(-16℃), CAMQL(-26℃) and wet

cutting have no sighnifcant difference.

CAMQL (-16℃) CAMQL (-26℃)

RESULTS AND DISCUSSIONS

Chips:

2. CAMQL, wet cutting and dry cutting



Cutting temperature of dry cutting is 100℃-150 ℃ higher than

CAMQL (-16℃) and CAMQL (-26℃).

CAMQL (-26℃) has lower temperature due to cooler cryogenic air.

RESULTS AND DISCUSSIONS 2. CAMQL, wet cutting and dry cutting

Cutting temperature:



CAMQL can reduce cutting force for a certain degree compared to

dry and wet cutting.

CAMQL (-16℃) is more significant in lowering cutting force than

CAMQL (-26℃).


Cutting forces:




CAMQL has the ability to reduce surface roughness compared to

dry and wet cutting.

The surface roughness of CAMQL (-16℃) and CAMQL (-26℃) is

similar.


Surface roughness :




CAMQL has the ability to reduce flank wear rate compared to dry and

wet cutting.

The surface roughness of CAMQL (-16℃) and CAMQL (-26℃) is similar.


Flank wear :




CAMQL (-26℃) CAMQL (-16℃)

vc=90 m/min, f=0.25 mm/r, ap=1 mm;cuttig distance: 360 m

The chip bulk of CAMQL(-16℃) is lager than CAMQL( -26℃) due to

higher cutting temperture, indicating servere adhension wear.


Rake face wear :




Wet cutting

Rake face of dry cutting is bonded with small chip bulk; Rake face

of wet cutting is bonded with larger chip bulk; and the breakage

and flaking were caused by heat impact.


Rake face wear :


caused by heat impact

Dry cutting

vc=90 m/min, f=0.25 mm/r, ap=1 mm

cuttig distance: 360 m



Both CAMQL (-16℃) and CAMQL (-26℃) have zone A, which

suffered adhesive-peeling-adhesive dynamic process.

CAMQL

(-26℃)

CAMQL

(-16℃)

vc=90 m/min, f=0.25 mm/r,

ap=1 mm; cuttig distance:

360 m


Flank wear :




Dry cutting Wet cutting

Breakage occured in flank face due to heat impact in wet cutting.

Severe flaking occured in flank face due to high cutting temperature in

dry cutting.

vc=90 m/min, f=0.25 mm/r, ap=1 mm;cuttig distance: 360 m


Flank wear :




Lubricant 2000-30 is slightly better in lowering the surface

roughness of CAMQL (-16℃) compared to 2000-10.


Surface roughness : using different lubricants




Lubricant 2000-30 can reduce the flank wear rate of CAMQL (-

16℃) compared to 2000-10.


Flank wear : using different lubricants




IOoW CAMQL

Suitable coated cutting tool should be selected in order to gain the best

cutting performance under these cooling methods in turing Ti-6Al-4V.

EOoW

RESULTS AND DISCUSSIONS 3. Flank wear rate of different coated tools under

EOoW, IOoW and CAMQL



Introduction 1

Experiment 2


Conclusions 4

CONTENTS



Function Heat transfer Lubrication

Media Water and cryogenic air

Oil

Spray location Rake face flank face

Cooling and lubricant by cryogenic air and the

penetration of oils directly

Lubricant by the penetration

of a few oils indirectly

Cooling and lubricant by the

penetration a few oils

indirectly

Cooling and lubricant by the

penetration a few oils

indirectly

Both cooling and lubricant by cryogenic air and the penetration of oils directly

rake

face

flank

face

rake and

flank faces

Conclusions Effect of EOoW in turning process:

EOoW



Function Heat transfer

Lubrication

Media Water Oil

Small amount of water (1.2 L/h) Large amount of water (2.4 L/h)

Oils on water Water on oils

Oil film form on the tool/chip and tool/workpiece interface leading to better lubrication.

No oli film on the cutting interface, oils are more easily to evaporate.

Conclusions Effect of IOoW in turning process:

IOoW



surface roughness:

IOoW (1.2 L/h) ＜ EOoW (flank face) ＜ CAMQL (-16 ℃)

BEST flank wear rate:

IOoW (1.2 L/h) ≈ CAMQL (-16 ℃)＜ EOoW (rake and flank face)

BEST

Conclusions Comparsion of EOoW, IOoW and CAMQL



In EOoW, water and cryogenic air, and oils play roles in heat

transfer and lubricating respectively. In IOoW, water is used for heat

transfer and oils are used for lubricating. Cryogenic air and oils play

roles in heat transfer and lubricating respectively in CAMQL.

The media of IOoW can spray deeply into the cutting zone, making

more oils penetrate to the cutting zone. Meanwhile, with a small

amount of water, oils in the form of oils on water would bond to the

surface of cutting tool and workpiece, then penetrate deeply into the

cutting zone and form the oil film.

Conclusions



The chip of EOoWf is much shorter than EOoWr for single spaying

direction of air from down to up making the chip much easier to

break. EOoWf has the lowest surface roughness, while EOoWrf has

the slowest flank wear rate. The bareness area of cutting tool

substrate-zone A is only absent from EOoWrf due to a better

lubricating effect. Lubricants have no inflence on surface roughness

and flank wear rate in EOoW.

Chip morphology of IOoW with different amounts of water is

continuous spiral. IOoW with less water will be better in lowering

surface roughness and reducing flank wear rate. The chip bulk and

bareness area of cutting tool substrate are absent when less water

is adopted due to better lubrication. Lubricants have a significant

effect in IOoW.

Conclusions



CAMQL with different air temperatures have the similar chip morphology with wet cutting. The surface roughness of CAMQL(-16℃) was slightly lower compared to CAMQL(-26℃), and they had almost the same flank wear rate. CAMQL has the lower surface roughness and slower flank wear rate compared to wet and dry cutting. CAMQL with -16℃ and -26℃ both have bareness area of cutting tool substrate due to insufficient lubrication.

The flank wear rates of cutting tools with different coating films have

the same sequence under EOoW, IOoW and CAMQL cooling, indicating that it is need to select suitable coated cutting tool in order to gain the best cutting performance under these cooling methods in turing Ti-6Al-4V.

Among EOoW, IOoW and CAMQL cooling, IOoW with lower quantity

of water has the best performance in lowering surface roughness and reducing flank wear in turning Ti-6Al-4V process.

Conclusions



Future Works

Internal cooling tunnel to avoid the transfer the heat much faster;

Nozzle structure design – forming much better oil mist, oil on water mist ;

Botanic or ester oil;

Mixed methods of coolant - cooled air/ oil mist (MQL)/ OoW for different material machining

Optimization of machining parameters for different material and machining method.

The project is funded by:

Guangdong-NSFC Jointed Major Project (U1201245)



谢谢


Documents

Tool wear in Ti-6Al-4V alloy turning under mixed cryogenic ... · Sino-German Center on Sustainable Manufacturing 2014, Germany, August 3rd–International Conference on Sustainable