Advisor: Professor Gaohui Wu
Student: Yutong Liu
Mechanical Properties of C f/AlComposite under High
Temperature Conditions
Page2
Background Fabrication Tests
Analysis Microstructure Conclusions
Content
Page3
Background
Content
Page4
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
Page5
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
Page6
Fabrication
Content
Page7
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.
Page8
Fabrication Method: Pressure Cast Method
Fabrication of C f/Al Composite
Page9
Heat Treatment Process: Annealing Process
(330℃ / 0.5h + Furnace Cooling)
330℃/0.5h
Furnace Cooling
T/℃
t/h
Fabrication of C f/Al Composite
Page10
Tests
Content
Page11
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
Page12
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
Page13
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
Page14
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
Page15
Analysis
Content
Page16
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
Page17
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℃
Page18
Composite Temperature Variation of BendingStrength -Deflection Curve
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
弯曲应力:1021.52MPa
弹性模量:147.19GPa
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
弯曲应力:466.87MPa
弹性模量:169.17GPa
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
弯曲应力:1046.29MPa
弹性模量:146.00GPa
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
弯曲应力:562.35MPa
弹性模量:178.03GPa
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
弯曲应力:1026.97MPa
弹性模量:133.72GPa
M40JBCf/LF6Al-三点弯曲-200℃-10
a) Cf /6061 Temperature variation of Bending Strength-Deflection Curveb) Cf /5A06 Temperature variation of Bending Strength-Deflection Curve
Page19
Composite Temperature Variation of BendingStrength -Deflection Curve
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
弹性模量:163.05GPa
L=40mm
V:2mm/min
D=10mm
M40JBCf/6061Al-三点弯曲-300℃-13
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
弯曲应力:686.77MPa
弹性模量:133.17GPa
M40JBCf/LF6Al-三点弯曲-300℃-14
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
弯曲应力:731.69MPa
弹性模量:125.36GPa
M40JBCf/6061Al-三点弯曲-350℃-29
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
弯曲应力:730.57MPa
弹性模量:723.60GPa
M40JBCf/LF6Al-三点弯曲-350℃-23
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
弯曲应力:555.59MPa
弹性模量:116.63GPa
L=40mm
V:2mm/min
D=10mm
M40JBCf/6061Al-三点弯曲-400℃-17
0 2 4 6 8 100
100
200
300
400
弯曲应力:406.97MPa
弹性模量:91.89GPa
L=40mm
V:2mm/min
D=10mm
M40JBCf/LF6Al-三点弯曲-400℃-18
挠度/mm
抗弯
强度
/MPa
a) Cf /6061 Temperature variation of Bending Strength-Deflection Curveb) Cf /5A06 Temperature variation of Bending Strength-Deflection Curve
Page20
Composite Temperature Variation of BendingStrength -Deflection Curve
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
弯曲应力:451.39MPa
弹性模量:112.70GPa
M40JBCf/6061Al-三点弯曲-450℃-33
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
弯曲应力:354.70MPa
弹性模量:101.26GPa
M40JBCf/LF6Al-三点弯曲-450℃-25
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
弹性模量:154.04GPa
L=40mm
V:2mm/min
D=10mm
M40JBCf/6061Al-三点弯曲-500℃-19
0 2 4 6 8 10 120
50
100
150
200
250
抗弯
强度
/MPa
挠度/mm
弯曲应力:214.53MPa
弹性模量:71.68GPa
L=40mm
V:2mm/min
D=10mm
M40JBCf/LF6Al-三点弯曲-500℃-20
a) Cf /6061 Temperature variation of Bending Strength-Deflection Curveb) Cf /5A06 Temperature variation of Bending Strength-Deflection Curve
Page21
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
Page22
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
Page23
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
Page24
Analysis
Interfaces decide composite strengthReinforcement -- Main force carrierMatrix -- Distribute strength in compositeInterfaces -- Transfer loads to reinforcement
Page25
Analysis
Weak interfaceFailure under lower stressDifficult to transfer load to reinforcementPoor Mechanical properties
Page26
Analysis
Strong interface
Cracks at interface extend easily
Interface adjust stress distribution poorly
Local stress concentration → low stress failure
Brittle Fracture no fibers extracted
Page27
Analysis
Moderate Interface
Cracks at interface extend gentlely
Certain amount fibers extracted
Energy depleted in discombination of fibers and matrix
Best Mechanical Properties
Page28
Microstructure
Content
Page29
Fracture Morphology Observation
Cf/6061Al
100℃30 Times 500 Times 1000 Times
200℃30 Times 500 Times 1000 Times
Page30
30 Times 500 Times 1000 Times
300℃
350℃
Fracture Morphology Observation
30 Times 500 Times 1000 Times
Page31
400℃
450℃
Fracture Morphology Observation
30 Times 500 Times 1000 Times
30 Times 500 Times 1000 Times
Page32
500℃
Fracture Morphology Observation
30 Times 500 Times 1000 Times
Page33
100℃
200℃
Fracture Morphology Observation
30 Times 500 Times 1000 Times
30 Times 500 Times 1000 Times
Cf/5A06Al
Page34
300℃
350℃
Fracture Morphology Observation
30 Times 500 Times 1000 Times
30 Times 500 Times 1000 Times
Page35
400℃
450℃
Fracture Morphology Observation
30 Times 500 Times 1000 Times
30 Times 500 Times 1000 Times
Page36
500℃
Fracture Morphology Observation
30 Times 500 Times 1000 Times
Page37
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
Fracture Morphology Observation
Filamentous Al appear on surface of CarbonFibers in Cf/5A06Al Under 400℃ Condition
Page38
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℃
Fracture Morphology Observation
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
Page39
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
Page40
TEM Microstructure Observation
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
Page41
TEM Microstructure Observation
TEM Microstructure of Cf/5A06Al Composite Three-Point Bending TestSpecimen Under 300℃ Condition
a) Dislocations in Matrix
b) c) Interphase Precipitate Phase
Page42
Conclusions
Content
Page43
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
Page44
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!