Andrew Schwartz 2018 Summer Internship · 2018 Summer Internship Materials and Processes Department Caterpillar: Confidential Green. Caterpillar: ... • Report issued August 1, 2018

Caterpillar: Confidential Yellow

M entor: Abdul Ahmed

Group M anager: M ark Lipschutz

Department M anager: Jose Aurrecoechea

Andrew Schwartz 2018 Summer InternshipMaterials and Processes Department

Caterpillar: Confidential Green

Caterpillar: Confidential YellowCaterpillar: Confidential Yellow

EM ERGENCY NUM BERS

HD – 5555

KM – 7500

CPR TRAINED AED FIRE EXTINGUISHER

Safety

2Caterpillar: Confidential Green

AGENDA

1. Personal Background

2. Projects

• Refurbishment Nozzle Wall Thickness

• Turbine Blade Condition Assessment

• High Speed EDM Drilling Study

• Additive M anufacturing Condition Assessment

3. Lessons Learned

4. Summer

5. Acknowledgements

AGENDA


2. Projects





3. Lessons Learned

4. Summer

5. Acknowledgements


Personal Background

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Personal Background



• Penn State University (B.S. M aterials Science and Engineering)August 2015- M ay 2019

• Applied Research Laboratory Advanced Coatings Group

January 2017- M ay 2019

- Thermal barrier coatings

- Non-destructive materials testing



Extracurriculars

• President of M aterials Advantage

• Keramos

• THON

• Ski Club

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Personal Background



Personal Background


AGENDA


2. Projects





3. Lessons Learned

4. Summer

5. Acknowledgements


Nozzle Wall Thickness

• Project- 1st and 2nd stage nozzle segments

- Refurbishment Process

• Process- Immediately refurbished part

- Visual inspection

- M etallography

- SEM / EDS



Nozzle Characteristics


Nozzle Insert Cooling Holes

Trailing Edge Pressure Side Aft Row Cooling Holes

• Uniform coating adhesion

• Blockages in cooling holes

• Insert coating spalling

Stage 2 Nozzle



SEM / EDS


Nickel Alloy Standard -RED

Nozzle Deposit -BLUE



Bulging Deformation of Previous Nozzles


Bulging in previous Nozzles

• Plastic deformation at 50% span of vanes

• Found on suction-side

• Not tested for on pressure-side






StageDesign Engineering

RequirementMid-Chord, 50%-Span Mid-Chord 20% Span Leading Edge, 80% Span

Stage 1 0.036”-0.50” 0.037” 0.030” 0.033”

Stage 2 0.030”-0.050” 0.028” 0.031” 0.020”

Nozzle Vane Bulging Test

Nozzle Wall Thickness Measurements

• Refurbishment after one service cycle

• Wall thickness below design

requirements

• Creep induced bulging of vane not

found



Results

• Coating material blockage of cooling holes

• Wall thinning from strip and recoat process of 1st and 2nd stage nozzles

• Potential for creep induced bulging

• Report issued August 1, 2018


AGENDA


2. Projects





3. Lessons Learned

4. Summer

5. Acknowledgements


Turbine Blade Condition Assessment

• Project- 1st and 2nd stage turbine blades underplatform regions

- Coke Oven Gas Environment

- Type II Hot Corrosion

• Process- Visual inspection

- Eddy current testing

- M etallography

- EDS



Type II Hot Corrosion

• Degrade Ni/ Co alloy via alkali salts in sulfur-rich gaseous environment

• Temperatures from 1050◦F- 1400◦F

• Coke Oven Gas


REF E.R.D.R. SR13-F-10283



Turbine Blade Deposit EDS


Presence of sulfur and alkali salts in deposits

consistent with coke oven gas fuel operation



Visual Analysis


1st Stage Turbine Blades 2nd Stage Turbine Blades

Pressure-side

Shank

Suction-side

Shank

Fir Tree

Fir Tree

Retainer

Wire HookAirfoil Tip

Airfoil Tip



Eddy Current Testing


Probe Fit-up for Underplatform Crack Detection

• Eddy currents (opposed currents) are induced in the conductive

material by wire coils inside orange film

• Changes in the conductivity of the material due to defects is

interpreted as amplitude fluctuations in magnetic field

• Impedance changes measured in wire coils indicate defects

Jentek Eddy Current System



1st Stage Turbine Blades


1st Stage Pressure-side 1st Stage Suction-side

All 1st stage blades passed eddy current testing



M etallographic Analysis


1st Stage Turbine Blade Fir Tree Contact Point

• No material cracks in high stress locations

• Coating cracks common

• Surface attack under contact points



Results

• 1st and 2nd stage turbine blades did not crack after high start cycles and 30K+ hours of service

• Hot corrosion effects not seen even in presence of sulfur and salt environment

• Potential for increasing engine service life

• Report issued August 9,2018


AGENDA


2. Projects





3. Lessons Learned

4. Summer

5. Acknowledgements


High Speed EDM Drilling Study

• Project- Samples with drilled holes

- Recast Cracking

- Low Cycle Fatigue Testing (LCF)

• Process- Visual inspection

- M etallography

- SEM


Matrix for LCF Testing

Standard Drilled & Reamed DR

Laser Drilled LS

Standard EDM Drilled EDM

High Speed EDM Drilled HS EDMREF Bob Klug



Nozzle Airfoil Test Samples


~ 1.50”

Wall thickness

~ 0.065 to 0.075”

0.020”

0.30”

Test Specimen Design• Gauge width of 0.30” with

• centered hole of 0.020”

REF Bob Klug



Issues Identified

• Hole shape irregularity

• Heavy recast layers

• M aterial damage


Entrance

Exit

REF Bob Klug



EDM vs. HS EDM


8c. EDM (2758 LCF cycles)

7c. HS EDM (4301 LCF cycles)

Fracture

Surfaces

Recast

Cracks



M etallography


8c. EDM

(2758 cycles)

7c. HS EDM

(4301 cycles)


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REF Bob Klug

Recast Layer Influence



Results

• Limited cracking propagating through recast layer

• Baseline LCF data with drilled holes

• Initial correlation between drilling method and LCF performance


AGENDA


2. Projects





3. Lessons Learned

4. Summer

5. Acknowledgements


Additive M anufacturing Condition Assessment

• Project- Additively manufactured swirler fuel injector

components

- Porosity measurements

• Process- M etallographic Porosity Inspections



Swirler W itness Samples



Porosity M easurements


Max. Percent PorosityMax. Pore Size

(inch)

Grade A Less than 0.15% 0.005

Grade B 0.15 to 0.25% 0.010

Grade C 0.25 to 0.5%

Grade D 0.5 to 0.75%

Exceeds greater than 0.75% greater than 0.015"

0.015

Porosity Inspection Grading System

REF EDM 15130



Results

• All batches passed porosity inspection

• Supports production groups

• Porosity analysis with PAX-it software

• Three reports issued


AGENDA


2. Projects





3. Lessons Learned

4. Summer

5. Acknowledgements


Lessons Learned

• Diverse projects that gave true industry experience

• Technical Skills- Eddy current testing

- SEM

- PAX-it Software

• Improved technical writing and presentation skills

• Professional networking


AGENDA


2. Projects





3. Lessons Learned

4. Summer

5. Acknowledgements


Summer in San Diego

• Beaches

• Hiking

• San Diego Fair

• Gaslamp District

• Travel


AGENDA


2. Projects





3. Lessons Learned

4. Summer

5. Acknowledgements

T H A N K Y O U

M aterials And Processes

Department

Abdul Ahmed

Rich Bellows

Brent Cottom

Hussam Jarmakani

Bob Klug

Prabhakar M ohan

Daniel Ryan

HR and Recruitment

Nancy Guardado

Karlen Castile

M ary Trefero

M aria Torres

Intern Coordinators

German Verduzco

Tyler Holmes

M anagement

John M ason

Jose Aurrecoechea

M ark Lipschutz

Summer Interns

Documents

Andrew Schwartz 2018 Summer Internship · 2018 Summer Internship Materials and Processes Department Caterpillar: Confidential Green. Caterpillar: ... • Report issued August 1, 2018