yutong liu - project - cf-al composites

Advisor: Professor Gaohui Wu

Student: Yutong Liu

Mechanical Properties of C f/AlComposite under High

Temperature Conditions

Background Fabrication Tests

Analysis Microstructure Conclusions

Content

Background

Content

Background

Metal Matrices Composites (MMCs) have a series advantages:

High Specific Strength High Modulus Ratio

High Thermal Conductivity High Electrical Conductivity

Low Thermal Expansion Coefficient

Excellent Irradiation Resistance

Good Thermal Endurance Anti-flammability

Non-hygroscopic Non Gas Effusion

MMCs have Broad Applications in High-Tech Fields:

Aerospace Aviation

Electronics Automobiles

Advanced Weapon Systems

Background

Aircraft structure can reach 300℃@ 3 times

sound speed flight

High-speed flight → Aerodynamic heating &

surface friction → High temperature

Temperature influence to Cf/Al composites

mechanical properties

Theoretical basis for Cf/Al composites

application in Aerospace Field

Fabrication

Content

Fabrication of C f/Al Composite

Reinforcement: M40JB Carbon Fiber

Matrices: 6061Al & 5A06Al

Fiber Volume Fraction: 50%

Carbon

Fiber

Tensile Strength /

MPa

Elastic Modulus /

GPa

Elongation

Rate / %

Density /

g/cm3

M40J 4410 377 1.2 1.77

Alloy Si Fe Cu Mn Mg Zn Be Ti Al

5A06Al 0.4 0.4 0.1 0.5-0.8 5.8-6.8 0.2 0.001-0.005 0.02-0.1 Bal.

6061Al 1.26 0.36 0.43 0.22 0.75 <0.15 <0.05 Bal.

Fabrication Method: Pressure Cast Method


Heat Treatment Process: Annealing Process

(330℃ / 0.5h + Furnace Cooling)

330℃/0.5h

Furnace Cooling

T/℃

t/h


Tests

Content

Research Scheme & Experiment Equipment

Experimental Project Experiment Equipment

Metallographic Observation ZEISS-40MAT Optical Microscope

Density Test BP211D Analytical Balance

Three-Point Bending TestINSTRON-5569 Universal Electronic Tensile

Testing Machine

TEM Observation Philips CM-12 Transmission Electron Microscope

SEM Observation S-4700 Scanning Electron Microscope

Density Test

Drainage Method:OH

OHair

air2

2

mm

m

Density / g/cm3 Cf Volume Fraction / %

Cf/6061Al 2.233 50.22

Cf/5A06Al 2.263 48.74

Metallography Observation

a）

d）c）

b）

a) Cf/6061 Composite 0° b) Cf/6061 Composite 90°c) Cf/5A06 Composite 0° d) Cf/5A06 Composite 90°

1000 Times

Three – Point Bending Test

Temperature:25℃,100℃,200℃,300℃,350℃,400℃,450℃,500℃Specimen Size:2×10×60mm 3 Specimen @ each TemperatureBending Span: l=40mm Indenter D: d=10mm Indenter V: 2mm/min

10

60

40

Analysis

Content

Mechanical Properties under Normal Temperature

0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.400

100

200

300

400

500

600 L=40mm

V：2mm/min

R=10mm

M40JBCf/6061Al-三点弯曲-室温-3

抗弯

强度

/MPa

挠度/mm

Three-Point Bending Test ：(Specimen Size: 2×10×60mm)

0.0 0.5 1.0 1.5 2.0 2.50

200

400

600

800

1000

1200

L=40mm

V：2mm/min

R=10mm

M40JBCf/LF6Al-三点弯曲-室温-3

抗弯

强度

/MPa

挠度/mm

Cf/6061 Composite a) 50 Times b) 500 Times

a）

d）c）

b）

Cf/5A06 Composite a) 50 Times b) 500 Times

Composite Temperature Variation of BendingStrength -Deflection Curve

a) Cf /6061 Temperature variation of Bending Strength-Deflection Curveb) Cf /5A06 Temperature variation of Bending Strength-Deflection Curve

0.0 0.5 1.0 1.5 2.00

100

200

300

400

500

600

700

800

挠度/mm

抗弯

强度

/MPa

L=40mm

V：2mm/min

R=10mm

M40JBCf/6061Al-不同温度下三点弯曲曲线

室温

100℃

200℃

300℃

350℃

400℃

450℃

500℃

0 1 2 3 4 5 60

200

400

600

800

1000

1200

L=40mm

V：2mm/min

R=10mm

挠度/mm

抗弯

强度

/MPa

M40JBCf/LF6Al-不同温度下三点弯曲曲线

室温

100℃

200℃

300℃

350℃

400℃

450℃

500℃


0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.350

100

200

300

400

500

弯曲应力：507.36MPa

弹性模量：169.51GPa

L=40mm

V：2mm/min

D=10mm

M40JBCf/6061Al-三点弯曲-室温-2

抗弯

强度

/MPa

挠度/mm

0.0 0.5 1.0 1.5 2.0 2.50

200

400

600

800

1000

1200



L=40mm

V：2mm/min

D=10mm

M40JBCf/LF6Al-三点弯曲-室温-2

抗弯

强度

/MPa

挠度/mm

0.00 0.05 0.10 0.15 0.20 0.25 0.300

100

200

300

400

500

抗弯

强度

/MPa

挠度/mm



L=40mm

V：2mm/min

D=10mm

M40JBCf/6061Al-三点弯曲-室100℃-8

0.0 0.2 0.4 0.6 0.8 1.0 1.20

200

400

600

800

1000

1200

挠度/mm

抗弯

强度

/MPa L=40mm

V：2mm/min

D=10mm



M40JBCf/LF6Al-三点弯曲-100℃-8

0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.350

100

200

300

400

500

600

抗弯

强度

/MPa

挠度/mm



L=40mm

V：2mm/min

D=10mm

M40JBCf/6061Al-三点弯曲-200℃-11

0.0 0.2 0.4 0.6 0.8 1.00

200

400

600

800

1000

1200

挠度/mm

抗弯

强度

/MPa L=40mm

V：2mm/min

D=10mm






0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.400

100

200

300

400

500

600 弯曲应力：602.40MPa


L=40mm

V：2mm/min

D=10mm


挠度/mm

抗弯

强度

/MPa

0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.50

100

200

300

400

500

600

700

抗弯

强度

/MPa

挠度/mm

L=40mm

V：2mm/min

D=10mm




0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.80

100

200

300

400

500

600

700

800

挠度/mm抗

弯强

度/MPa L=40mm

V：2mm/min

D=10mm




0 1 2 3 4 5 6 7 80

100

200

300

400

500

600

700

800

挠度/mm

抗弯

强度

/MPa

L=40mm

V：2mm/min

D=10mm




0.0 0.1 0.2 0.3 0.4 0.50

100

200

300

400

500

600

挠度/mm

抗弯

强度

/MPa



L=40mm

V：2mm/min

D=10mm


0 2 4 6 8 100

100

200

300

400



L=40mm

V：2mm/min

D=10mm


挠度/mm

抗弯

强度

/MPa



0 1 2 3 4 5 6 70

100

200

300

400

500

挠度/mm

抗弯

强度

/MPa

L=40mm

V：2mm/min

D=10mm




0 1 2 3 4 5 6 7 80

50

100

150

200

250

300

350

400

挠度/mm

抗弯

强度

/MPa

L=40mm

V：2mm/min

D=10mm




0 1 2 3 4 5 6 7 80

100

200

300

400

500

挠度/mm

抗弯

强度

/MPa 弯曲应力：500.30MPa


L=40mm

V：2mm/min

D=10mm


0 2 4 6 8 10 120

50

100

150

200

250

抗弯

强度

/MPa

挠度/mm



L=40mm

V：2mm/min

D=10mm



Composite Elastic Modulus Variation withTemperature

a) Cf /6061 Elastic Modulus Variation with Temperatureb) Cf /5A06 Elastic Modulus Variation with Temperaturec) Relative Variation Trend of Elastic Modulus

0 100 200 300 400 5000

50

100

150

200

温度/℃

弹性

模量

/GPa

L=40mm

V：2mm/min

D=10mm

M40JBCf/6061Al-三点弯曲-弹性模量-温度变化曲线

0 100 200 300 400 5000

50

100

150

200

250

弹性

模量

/GPa

温度/℃

L=40mm

V：2mm/min

D=10mm

M40JBCf/LF6Al-三点弯曲-弹性模量-温度变化曲线

0 100 200 300 400 500

-60

-40

-20

0

20

40

60M40JBC

f/6061Al和M40JBC

f/6061Al-三点弯曲-弹性模量相对变化

L=40mm

V：2mm/min

D=10mm

温度/℃弹

性模

量相

对变

化/%

6061Al基体

LF6Al基体

Composite Bending Strength Variation withTemperature

0 100 200 300 400 5000

50100150200250300350400450500550600650700750800

温度/℃

抗弯

强度

/MPa

L=40mm

V：2mm/min

D=10mm

M40JBCf/6061Al-三点弯曲-抗弯强度-温度变化曲线

0 100 200 300 400 5000

200

400

600

800

1000

1200

1400

温度/℃

抗弯

强度

/MPa

L=40mm

V：2mm/min

D=10mm

M40JBCf/LF6Al-三点弯曲-抗弯强度-温度变化曲线

0 100 200 300 400 500

-100

-80

-60

-40

-20

0

20

40

温度/℃

抗弯

强度

相对

变化

/%

L=40mm

V：2mm/min

D=10mm

M40JBCf/6061Al和M40JBC

f/6061Al-三点弯曲-抗弯强度相对变化

6061Al基体

LF6Al基体

a) Cf /6061 Bending Strength Variation with Temperatureb) Cf /5A06 Bending Strength Variation with Temperaturec) Relative Variation Trend of Bending Strength

Composite Bending Deflection Variation withTemperature

0 100 200 300 400 500 6000

2

4

6

8

10

12

L=40mm

V：2mm/min

D=10mm

挠度

/mm

温度/℃

M40JBCf/6061Al-三点弯曲挠度

0 100 200 300 400 500 6000

2

4

6

8

10

12

14

16

18

L=40mm

V：2mm/min

D=10mm

挠度

/mm

温度/℃

M40JBCf/LF6Al-三点弯曲挠度

0 100 200 300 400 500 6000

2

4

6

8

10

12

14

16

18

6061Al基体

LF6Al基体

弹性

模量

/mm

温度/℃

M40JBCf/6061Al和M40JBC

f/6061Al-三点弯曲-挠度变化

a) Cf /6061 Bending Deflection Variation with Temperatureb) Cf /5A06 Bending Deflection Variation with Temperaturec) Relative Variation Trend of Bending Deflection

Analysis

Interfaces decide composite strengthReinforcement -- Main force carrierMatrix -- Distribute strength in compositeInterfaces -- Transfer loads to reinforcement

Analysis

Weak interfaceFailure under lower stressDifficult to transfer load to reinforcementPoor Mechanical properties

Analysis

Strong interface

Cracks at interface extend easily

Interface adjust stress distribution poorly

Local stress concentration → low stress failure

Brittle Fracture no fibers extracted

Analysis

Moderate Interface

Cracks at interface extend gentlely

Certain amount fibers extracted

Energy depleted in discombination of fibers and matrix

Best Mechanical Properties

Microstructure

Content

Fracture Morphology Observation

Cf/6061Al

100℃30 Times 500 Times 1000 Times

200℃30 Times 500 Times 1000 Times

30 Times 500 Times 1000 Times

300℃

350℃



400℃

450℃




500℃



100℃

200℃




Cf/5A06Al

300℃

350℃




400℃

450℃




500℃



Element Wt% At%

C K 31.21 50.21

O K 00.59 00.71

MgK 03.05 02.42

AlK 65.15 46.66

SiK 00.00 00.00


Filamentous Al appear on surface of CarbonFibers in Cf/5A06Al Under 400℃ Condition

Element Wt% At%

C K 62.09 78.04

O K 01.89 01.78

MgK 00.45 00.28

AlK 35.57 19.90

SiK 00.00 00.00

500℃


Filamentous Al appear on surface of CarbonFibers in Cf/6061Al Under 500℃ Condition

No Filamentous Al appear on Cf surface inCf/6061Al Under 400℃ Condition

TEM Microstructure Observation

TEM Microstructure of Cf/6061Al Composite Three-Point Bending TestSpecimen Under 300℃ Condition

a) Dislocations in Matrix

b) Interphase Precipitate Phase

c) Precipitate Phase Diffraction Spots


TEM Microstructure of Cf/6061Al Composite Three-Point Bending TestSpecimen Under 500℃ Condition

a) Acicular Precipitate Phase

b) Matrix Diffraction Spots

c) Precipitate Phase Diffraction Spots


TEM Microstructure of Cf/5A06Al Composite Three-Point Bending TestSpecimen Under 300℃ Condition

a) Dislocations in Matrix

b) c) Interphase Precipitate Phase

Conclusions

Content

Conclusions

Bending Strength Elastic Modulus Bending Deflection Interface

Cf/6061 771MPa300℃ 178GPa

300℃ 20×Room T Deflect500℃ Strong

Interface

Cf/5A06 1207MPa100/200℃ 240GPa

350℃ 6×Room T Deflect500℃ Moderate

Interface

25℃ 300℃ 500℃Cf/6061 Much Brittle Phase Al4C3 Less Brittle Phase Al4C3 Al Matrix soften Al2O3

Cf/5A06 No Brittle Phase Al4C3 Brittle Phase Al58Mg42 Al Matrix soften Al2O3

Critical Values

Phase @ Interface

Conclusions

Temperature Variations of Mechanical Properties are thesame -- increase first and then decrease

Cf/6061Al Temperature Variation lags behind Cf/5A06Al

Cf/5A06Al has better Mechanical properties in general &fits high temperature condition better

Recommend Cf/5A06Al to applications in AerospaceEngineering & Advanced Weapon Systems

Thank you!

yutong liu - project - cf-al composites

Documents