Tensile and Fracture Behaviors of Stitched Twill Carbon Fabric Structure Reinforced Aluminum Matrix Composites at Elevated Temperature

doi:10.11900/0412.1961.2023.00469

Acta Metall Sin

2025, Vol. 61

Issue (9): 1387-1402 DOI: 10.11900/0412.1961.2023.00469

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Tensile and Fracture Behaviors of Stitched Twill Carbon Fabric Structure Reinforced Aluminum Matrix Composites at Elevated Temperature

WU Zhiyong¹, SHAO Huifan¹, CAI Changchun¹, ZENG Min¹, WANG Zhenjun¹(

), WANG Yanli², CHEN Lei², XIONG Bowen¹

1 School of Aeronautical Manufacturing Engineering, Nanchang Hangkong University, Nanchang 330063, China
2 AVIC Jiangxi Hongdu Aviation Industry Group Co. Ltd., Nanchang 330096, China

Cite this article:

WU Zhiyong, SHAO Huifan, CAI Changchun, ZENG Min, WANG Zhenjun, WANG Yanli, CHEN Lei, XIONG Bowen. Tensile and Fracture Behaviors of Stitched Twill Carbon Fabric Structure Reinforced Aluminum Matrix Composites at Elevated Temperature. Acta Metall Sin, 2025, 61(9): 1387-1402.

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Abstract

Three-dimensional fabric-reinforced aluminum matrix composites with high specific strength and modulus, excellent high-temperature resistance, and impact resistance are ideal structural materials for fabricating heat-resistant components in aeronautics and aerospace engineering. However, few studies have explored the mechanical properties and fracture behaviors of these composites in high-temperature environments. This study aims to investigate the quasi-static tensile behaviors and failure mechanisms of a stitched twill carbon fabric-reinforced aluminum matrix composite at an elevated temperature of 400 ^oC. Based on the fabric structure and yarn microstructure, a mesoscle finite element model was established using representative unit cells at the microsale and mesoscale. The macroscopic mechanical response, damage evolution, and failure mechanism of the composite during the tensile test at an elevated temperature (400 ^oC) were analyzed through numerical simulations and experiments. Results show that the tested tensile modulus, strength, and fracture strain at 400 ^oC are 103.20 GPa, 621.60 MPa, and 0.819%, respectively. The calculated tensile stress-strain curve aligns with the experimental curves obtained from high-temperature tensile tests. The composites experience complex thermal stress at elevated temperatures, with the matrix pocket under compressive stress and the yarn structure under tensile stress. In the initial tensile stage, the matrix between interlaced weft/warp yarns is damaged, and local failure zones appear in the stitch and warp yarns; however, the composite exhibits a linear elastic response. As the tensile load increases, the degree of damage in the matrix pocket gradually increases, leading to the emergence of serious matrix damage zones and weft yarn cracking along the twill direction of the fabric. Consequently, the growth rate of tensile stress in the tensile curve declines with increasing tensile strain. In the final stage, the matrix failure zone and yarn fracture zone overlap. The axial fracture of warp yarn, in particular, leads to catastrophic fracture of the composite, resulting in a dramatic drop of the tensile stress. The stitch and weft yarns in the composites exhibit a flat fracture morphology, whereas the fractured warp yarn presents rugged fracture surfaces. A mass of fiber pull-out is observed on the microscopic fracture surface of a warp yarn, accompanied by matrix alloy tearing characteristics.

Key words: stitched twill carbon fabric structure aluminum matrix composites micromechanics damage evolution high temperature mechanical property failure mechanism

Received: 01 December 2023

ZTFLH:

TG335.85

Fund: National Natural Science Foundation of China(52165018);Jiangxi Provincial Program for Cultivating Academic and Technical Leaders in Key Disciplines(20225BCJ22002)

Corresponding Authors: WANG Zhenjun, professor, Tel: 18970951974, E-mail: wangzhj@nchu.edu.cn

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	Articles by authors
	WU Zhiyong
	SHAO Huifan
	CAI Changchun
	ZENG Min
	WANG Zhenjun
	WANG Yanli
	CHEN Lei
	XIONG Bowen

URL:

https://www.ams.org.cn/EN/10.11900/0412.1961.2023.00469 OR https://www.ams.org.cn/EN/Y2025/V61/I9/1387

Fig.1 Schematic (a) and surface morphology (b) of stitched twill carbon fabric, and surface morphology of aluminum matrix composites (c)

Fig.2 Schematics of dimensions of aluminum matrix composites (a) and aluminum alloy (b) specimens for tensile test at elevated temperature (unit: mm)

Fig.3 Cross-sectional OM images (a-c) and SEM image (d) of yarns in the aluminum matrix composites
(a) warp yarns (b) weft yarns (c) stitch yarns (d) microstructure of warp yarns

Fig.4 Schematics of modeling process of the aluminum matrix composites mesoscale structure
(a) yarn section (unit: mm) (b) yarn arrangement (c) mesoscale structure modeling

Fig.5 Mesoscale representative volume element (RVE) model (a), discretized RVE model (b), and periodic boundary conditions (c) of the aluminum matrix composites

Fig.6 Tensile engineering stress-strain curves of the matrix aluminum alloys at different temperatures

Temperature / ^oC	E^m / GPa	$ε ¯ 0 p l$ / %	$ε ¯ f p l$ / %	α / (10^-6 K^-1)^[34]
25	70.48	0.27	1.2	22.7
100	45.65	0.43	1.5	25.4
200	33.14	0.74	2.0	26.5
300	24.22	2.20	3.2	27.8
400	12.89	3.20	4.5	29.9

Table 1 Elastic-plastic mechanical property parameters and thermal expansion coefficients^[34] of the matrix aluminum alloy

Fig.7 Arrangement schematic (a), microscale RVE model (unit: μm) (b), and discretized RVE model (c) of hcp fiber

Parameter	Symbol	Value	Unit	Ref.
Axial tensile strength	$X t f$	4400	MPa	[41]
Axial compressive strength	$X c f$	2250	MPa	[33]
Axial shear strength	$S 12 f$	340	MPa	[33]
Axial elastic modulus	$E 11 f$	377	GPa	[41]
Axial shear modulus	$G 12 f$	8.9	GPa	[39]
Axial Poisson's ratio	$ν 12 f$	0.26		[33]
Axial thermal expansion coefficient	$α 11 f$	-0.83	10^-6 K^-1	[39]
Transverse tensile strength	$Y t f$	175	MPa	[40]
Transverse compressive strength	$Y c f$	590	MPa	[40]
Transverse shear strength	$S 23 f$	240	MPa	[40]
Transverse elastic modulus	$E 22 f$	19	GPa	[39]
Transverse shear modulus	$G 23 f$	7.3	GPa	[40]
Transverse Poisson's ratio	$ν 23 f$	0.3		[33]
Transverse thermal expansion coefficient	$α 22 f$	8.0	10^-6 K^-1	[39]

Table 2 Elastic constants, ultimate strengths, and thermal expansion coefficients of fiber^[33,39-41]

Fig.8 Predicted high-temperature (400 ^oC) mechanical behavior of the yarns under different loads based on the microscale RVE finite element model

Parameter	Symbol	Value	Unit
Axial tensile modulus	$E 11 t$	262.8	GPa
Axial compression modulus	$E 11 c$	259.4	GPa
Axial shear modulus	$G 12 s$	8.9	GPa
Transverse tensile modulus	$E 22 t$	19.8	GPa
Transverse compression modulus	$E 22 c$	20.3	GPa
Transverse shear modulus	$G 23 s$	7.2	GPa
Axial tensile strength	$X 11 t$	3027.1	MPa
Axial compression strength	$X 11 c$	1577.4	MPa
Axial shear strength	$X 12 s$	39.9	MPa
Transverse tensile strength	$X 22 t$	83.6	MPa
Transverse compression strength	$X 22 c$	86.1	MPa
Transverse shear strength	$X 23 s$	38.9	MPa

Table 3 High-temperature elastic constants and ultimate strengths of the yarn

Temperature / ^oC	α₁₁ / (10^-6 K^-1)	α₂₂ / (10^-6 K^-1)	E₁₁ / GPa	E₂₂ / GPa	G₁₂ / GPa	G₂₃ / GPa	$ν$ ₁₂	$ν$ ₂₃
25	3.11	9.94	283.28	23.98	11.03	9.34	0.28	0.41
100	3.03	10.28	282.11	23.50	10.89	8.91
200	2.94	10.39	275.99	22.80	10.54	8.68
300	2.82	10.53	269.96	22.19	9.69	8.06
400	2.68	10.78	268.11	21.86	9.42	7.86

Table 4 Linear thermal expansion coefficients and elastic constants of the yarns at different temperatures

Fig.9 Schematics of local material coordinate of yarns in the mesoscale RVE model (arrow 1—axial direction of the yarn; arrows 2 and 3—transverse directions of the yarn)
(a) warp yarn
(b) weft yarn
(c) stitch yarn

Fig.10 Thermal residual stress distributions in the aluminum matrix composites at 400 ^oC
(a) matrix pocket (b) yarn structure

Fig.11 Tensile stress-strain curves obtained from the tensile tests and predicted by the mesoscale finite element simulation at 400 ^oC (ε—strain)

Table 5 High-temperature tensile properties obtained from the experiment and simulation

Fig.12 Local damage and failure state of the component structures at the tensile strain of 0.2009% (SDEG—damage factor of the matrix pocket, FV1—failure index of the yarns)
(a) matrix pocket (b) warp yarns (c) weft yarns (d) stitch yarns

Fig.13 Local damage and failure state of the component structures at the tensile strain of 0.6185%
(a) matrix pocket (b) warp/weft yarns (c) stitch yarns

Fig.14 Local damage and failure state of the component structures at the tensile strain of 0.8504%
(a) matrix pocket (b) warp/weft yarns (c) stitch yarns

Fig.15 Low (a) and high (b-e) magnified tensile fracture morphologies of the aluminum matrix composites at 400 ^oC
(a-c) fracture morphologies of yarn structure
(d) fracture morphology of warp yarn
(e) fiber pull out and matrix tearing in warp yarn

Fig.16 Failure modes of the yarn structures after the high-temperature tensile fracture (SDV1—axial failure index, SDV2—width directional failure index, SDV3—thickness directional failure index. 1 represents principal axis, 2 and 3 represent two transverse dimensions)
(a) axial failure state of the warp yarns
(b) thickness directional failure state of the warp yarns
(c) width directional failure state of the weft yarns
(d) width directional failure state of the stitch yarns

[1]	Miracle D B. Metal matrix composites—From science to technological significance [J]. Compos. Sci. Technol., 2005, 65: 2526
[2]	Wenzelburger M, Silber M, Gadow R. Manufacturing of light metal matrix composites by combined thermal spray and semisolid forming process—Summary of the current state of technology [J]. Key Eng. Mater., 2010, 425: 217
[3]	Wang Y, Xu X, Zhao W X, et al. Damage accumulation during high temperature fatigue of Ti/SiC_f metal matrix composites under different stress amplitudes [J]. Acta Mater., 2021, 213: 116976
[4]	Ma Z Y, Xiao B L, Zhang J F, et al. Overview of research and development for aluminum matrix composites driven by aerospace equipment demand [J]. Acta Metall. Sin., 2023, 59: 457 doi: 10.11900/0412.1961.2022.00605
	马宗义, 肖伯律, 张峻凡等. 航天装备牵引下的铝基复合材料研究进展与展望 [J]. 金属学报, 2023, 59: 457 doi: 10.11900/0412.1961.2022.00605
[5]	Kim B R, Lee H K. Elastoplastic modeling of circular fiber-reinforced ductile matrix composites considering a finite RVE [J]. Int. J. Solids Struct., 2010, 47: 827
[6]	Chen Y L, Ghosh S. Micromechanical analysis of strain rate-dependent deformation and failure in composite microstructures under dynamic loading conditions [J]. Int. J. Plast., 2012, 32-33: 218
[7]	Giugliano D, Barbera D, Chen H F. Effect of fiber cross section geometry on cyclic plastic behavior of continuous fiber reinforced aluminum matrix composites [J]. Eur. J. Mech., 2017, 61A: 35
[8]	Giugliano D, Chen H F. Micromechanical modeling on cyclic plastic behavior of unidirectional fiber reinforced aluminum matrix composites [J]. Eur. J. Mech., 2016, 59A: 155
[9]	Zhu X J, Chen X F, Zhai Z, et al. Micromechanical analysis of interfacial debonding in metal matrix composites subjected to off-axis loading [J]. Fiber Compos., 2013, 3: 53
[10]	Behera N, Murari Pandey K M, Deoghare A B, et al. Modeling & simulation of interface stability in metal matrix composites subjected to off-axis loading using cohesive zone model under elevated temperature: A review [J]. Mater. Today Proc., 2018, 5: 20085
[11]	Eggleston M R, Krempl E. The transverse creep and tensile behaviour of SCS-6/Ti-6Al-4V metal matrix composites at 482 ^oC [J]. Mech. Compos. Mater. Struct., 1994, 1: 53
[12]	Aghdam M M, Morsali S R, Hosseini S M A, et al. Mechanical behavior of unidirectional SiC/Ti composites subjected to off-axis loading at elevated temperatures [J]. Mater. Sci. Eng., 2017, A688: 244
[13]	Aghdam M M, Morsali S R. Damage initiation and collapse behavior of unidirectional metal matrix composites at elevated temperatures [J]. Comput. Mater. Sci., 2013, 79: 402
[14]	Vassel A. Continuous fibre reinforced titanium and aluminium composites: A comparison [J]. Mater. Sci. Eng., 1999, A263: 305
[15]	Zhang Y H, Yan L L, Miao M H, et al. Microstructure and mechanical properties of z-pinned carbon fiber reinforced aluminum alloy composites [J]. Mater. Des., 2015, 86: 872
[16]	Zhang Y, Wu G, Chen G, et al. Microstructure and mechanical properties of 2D woven Gr_f/Al composite [J]. Trans. Noferrous Met. Soc. China, 2006, 16(spec. issue3) : S1509
[17]	Ma Y Q, Qi L H, Zheng W Q, et al. Effect of specific pressure on fabrication of 2D-C_f/Al composite by vacuum and pressure infiltration [J]. Trans. Nonferrous Met. Soc. China, 2013, 23: 1915
[18]	Zhou J M, Zheng W Q, Qi L H, et al. Investigation on compressive failure mechanism of 2D cross-ply C_f/Al composites by extrusion directly following vacuum pressure infiltration process [J]. J. Shanghai Univ. (Nat. Sci.), 2014, 20: 75
	周计明, 郑武强, 齐乐华等. 真空吸渗挤压二维正交铺层复合材料压缩失效机制 [J]. 上海大学学报(自然科学版), 2014, 20: 75
[19]	Hufenbach W, Gude M, Czulak A. Development of textile-reinforced carbon fibre aluminium composites manufactured with gas pressure infiltration methods [J]. J. Achiev. Mater. Manuf. Eng., 2009, 2: 177
[20]	Yang Q R, Liu J X, Li S K, et al. Fabrication and mechanical properties of Cu-coated woven carbon fibers reinforced aluminum alloy composite [J]. Mater. Des., 2014, 57: 442
[21]	Yang Q R, Liu J X, Li S K, et al. Bending mechanical property and failure mechanisms of woven carbon fiber-reinforced aluminum alloy composite [J]. Rare Met., 2016, 35: 915
[22]	Zhang J J, Liu S C, Zhang Y X, et al. Fabrication of woven carbon fibers reinforced Al-Mg (95-5wt%) matrix composites by an electromagnetic casting process [J]. J. Mater. Process. Technol., 2015, 226: 78
[23]	Zhang J J, Liu S C, Lu Y P, et al. Semisolid-rolling and annealing process of woven carbon fibers reinforced Al-matrix composites [J]. J. Mater. Sci. Technol., 2017, 33: 623 doi: 10.1016/j.jmst.2017.01.002
[24]	Lee S K, Byun J H, Hong S H. Effect of fiber geometry on the elastic constants of the plain woven fabric reinforced aluminum matrix composites [J]. Mater. Sci. Eng., 2003, A347: 346
[25]	McWilliams B, Dibelka J, Yen C F. Multi scale modeling and characterization of inelastic deformation mechanisms in continuous fiber and 2D woven fabric reinforced metal matrix composites [J]. Mater. Sci. Eng., 2014, A618: 142
[26]	Sheng G F, Wang Z J, Liu F H, et al. Quasi-static tensile behavior and failure mechanism of laminated puncture CF/Al composites [J]. Acta Aeronaut. Astronaut. Sin., 2021, 42(12): 345
	沈高峰, 王振军, 刘丰华等. 叠层穿刺CF/Al复合材料准静态拉伸力学行为与失效机制 [J]. 航空学报, 2021, 42(12): 345
[27]	Feng J P, Yu H, Xu Z F, et al. Bending properties and failure analysis of laminated puncture structural C_f/Al composites [J]. Chin. J. Nonferrous Met., 2020, 30: 2597
	冯景鹏, 余欢, 徐志锋等. 叠层穿刺结构C_f/Al复合材料的弯曲性能及失效分析 [J]. 中国有色金属学报, 2020, 30: 2597
[28]	Gu S, Cai C C, Yu H, et al. Residual compression mechanical properties after low-speed impact for laminated stitched carbon fiber reinforced aluminum matrix composite [J]. J. Aeronaut. Mater., 2022, 42(3): 80
	顾姝, 蔡长春, 余欢等. 叠层缝合碳纤维增强铝基复合材料低速冲击及冲击后剩余压缩力学性能 [J]. 航空材料学报, 2022, 42(3): 80
[29]	Nie M M, Xu Z F, Yu H, et al. Micro-defects of 3D-C_f/Al composites by vacuum pressure infiltration [J]. Rare Met. Mater. Eng., 2018, 47: 1266
	聂明明, 徐志锋, 余欢等. 真空气压浸渗3D-C_f/Al复合材料微观缺陷分析 [J]. 稀有金属材料与工程, 2018, 47: 1266
[30]	Wang L, Wu J Y, Chen C Y, et al. Progressive failure analysis of 2D woven composites at the meso-micro scale [J]. Compos. Struct., 2017, 178: 395
[31]	Li S G. Boundary conditions for unit cells from periodic microstructures and their implications [J]. Compos. Sci. Technol., 2008, 68: 1962
[32]	Xia Z H, Zhang Y F, Ellyin F. A unified periodical boundary conditions for representative volume elements of composites and applications [J]. Int. J. Solids Struct., 2003, 40: 1907
[33]	Wang Z J, Zhao W H, Wang F, et al. Tensile behavior and failure mechanism of 3D woven fabric reinforced aluminum composites [J]. Int. J. Mech. Sci., 2023, 244: 108043
[34]	Hidnert P. Thermal expansion of aluminum and various important aluminum alloys [J]. J. Franklin Inst., 1925, 199(4): 539
[35]	ABAQUS. Version 6.12 Documentation. Dassault Systemes Simulia Corp. Providence, RI, USA, 2012
[36]	Wang Z J, Wang Z Y, Xiong B W, et al. Micromechanics analysis on the microscopic damage mechanism and mechanical behavior of graphite fiber-reinforced aluminum composites under transverse tension loading [J]. J. Alloys Compd., 2020, 815: 152459
[37]	Xu Q, Qu S X. Irreversible deformation of metal matrix composites: A study via the mechanism-based cohesive zone model [J]. Mech. Mater., 2015, 89: 72
[38]	Lou J H, Yang Y Q, Luo X, et al. The analysis on transverse tensile behavior of SiC/Ti-6Al-4V composites by finite element method [J]. Mater. Des., 2010, 31: 3949
[39]	Rupnowski P, Gentz M, Sutter J K, et al. An evaluation of the elastic properties and thermal expansion coefficients of medium and high modulus graphite fibers [J]. Composites, 2005, 3A: 327
[40]	Kawabata S. Measurement of the transverse mechanical properties of high performance fibres [J]. J. Text. Inst., 1990, 81: 432
[41]	Zhou Y X, Jiang D Z, Xia Y M. Tensile mechanical behavior of T300 and M40J fiber bundles at different strain rate [J]. J. Mater. Sci., 2001, 36: 919
[42]	Kaddour A, Hinton M. Maturity of 3D failure criteria for fiber-reinforced composites: Comparison between theories and experiments: Part B of WWFE-II [J]. J. Compos. Mater., 2013, 47: 925
[43]	He Q Q, Zhou C W, Zhou C. Micro-mechanical model of thermal expansion/contraction for damaged fiber reinforced composites [J]. Acta Mater. Compos. Sin., 2014, 31: 1077
	何乾强, 周储伟, 周灿. 纤维增强复合材料考虑损伤的温度胀缩细观力学模型 [J]. 复合材料学报, 2014, 31: 1077
[44]	Schapery R A. Thermal expansion coefficients of composite materials based on energy principles [J]. J. Compos. Mater., 1968, 2: 380
[45]	Yates B, McCalla B A, Sargent J P, et al. The thermal expansion of carbon fibre reinforced plastics: Part 3 The influence of resin type [J]. J. Mater. Sci., 1978, 13: 2217
[46]	Hopkins D A, Chamis C C. A unique set of micromechanics equations for high-temperature metal matrix composites [A]. The First Symposium on Testing Technology of Metal Matrix Composites [C]. Nashvilley: ASTM STP, 1985, 159
[47]	Li D G, Chen G Q, Jiang L T, et al. Effect of thermal cycling on the mechanical properties of C_f/Al composites [J]. Mater. Sci. Eng., 2013, A586: 330
[48]	Zhou L, Zhang P F, Wang Q Z, et al. Multi-scale study on the fracture behavior of hot compression B₄C/6061Al composite [J]. Acta Metall. Sin., 2019, 55: 911
	周丽, 张鹏飞, 王全兆等. B₄C/6061Al复合材料热压缩断裂行为的多尺度研究 [J]. 金属学报, 2019, 55: 911

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