Fracture Behavior of Particle Reinforced Metal Matrix Composites

2009 ◽  
Vol 79-82 ◽  
pp. 1487-1490
Author(s):  
Wei Dong Song ◽  
Hai Yan Liu ◽  
Jian Guo Ning

SEM experimental system was employed to investigate the fracture behavior of particle reinforced metal matrix composites (91%wt tungsten alloys) by in-situ experiments. The fracture patterns of tungsten alloys under tensile loading were examined. Multi-particle unit cell models containing some important microstructure characteristics of tungsten alloys were established. By using fixed point iteration method, the displacement constraint conditions were applied on the multi-particle unit cell and the mechanical properties of tungsten alloys under tensile loadings were simulated. Comparison of the experimental results and the numerical predictions shows a good agreement between them, verifying the rationality of the FE models using the fixed point iteration method.

2011 ◽  
Vol 25 (11) ◽  
pp. 1475-1492 ◽  
Author(s):  
WEIDONG SONG ◽  
HAIYAN LIU ◽  
JIANGUO NING

In situ SEM experimental system is employed to investigate the mechanical characteristics and the fracture behavior of 91W–6.3Ni–2.7Fe tungsten alloys. The crack initiation and propagation of tungsten alloys under tensile loadings are examined. Multi-particle unit cell models containing the microstructure characteristics of tungsten alloys are established. Fixed-point iteration method is firstly used for the multi-particle unit cell's boundary condition. By adopting the method, real displacement constrained conditions are applied on the multi-particle unit cell models. The mechanical and fracture behaviors of tungsten alloys under tensile loading are simulated. The effects of tungsten content, particle shape, particle size, and interface strength on the mechanical properties of tungsten alloys are analyzed. The relationship between the mechanical behaviors and the microstructure parameters is studied. A good agreement is obtained between the experimental results and the numerical predictions, verifying the rationality of the FE models using the fixed-point iteration method.


2009 ◽  
Vol 417-418 ◽  
pp. 441-444
Author(s):  
Wei Dong Song ◽  
Hai Yan Liu ◽  
Jian Guo Ning

Fixed point iteration method for multi-particle unit cell’s boundary condition is presented. On the basis of this method, the macroscopic effective material parameters can be obtained from a microscopic point of view. Multi-particle unit cell models containing some important microstructure characteristics of TP-650 titanium matrix composites are established. The real displacement constrained conditions are applied on the multi-particle unit cell using this method, and the mechanical properties and fracture behaviors of the composites under tensile loading are simulated. A good agreement was obtained between the experimental results and the numerical predictions, which verifying the rationality of the FE models based on fixed point iteration method.


Author(s):  
Partha Rangaswamy ◽  
N. Jayaraman

Abstract In metal matrix composites residual stresses developing during the cool-down process after consolidation due to mismatch in thermal expansion coefficients between the ceramic fibers and metal matrix have been predicted using finite element analysis. Conventionally, unit cell models consisting of a quarter fiber surrounded by the matrix material have been developed for analyzing this problem. Such models have successfully predicted the stresses at the fiber-matrix interface. However, experimental work to measure residual stresses have always been on surfaces far away from the interface region. In this paper, models based on the conventional unit cell (one quarter fiber), one fiber, two fibers have been analyzed. In addition, using the element birth/death options available in the FEM code, the surface layer removal process that is conventionally used in the residual stress measuring technique has been simulated in the model. Such layer removal technique allows us to determine the average surface residual stress after each layer is removed and a direct comparison with experimental results are therefore possible. The predictions are compared with experimental results of an eight-ply unidirectional composite with Ti-24Al-11 Nb as matrix material reinforced with SCS-6 fibers.


Metals ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 4 ◽  
Author(s):  
Kuan Gao ◽  
Xin Zhang ◽  
Baoxi Liu ◽  
Jining He ◽  
Jianhang Feng ◽  
...  

Multilayer metal composites have great application prospects in automobiles, ships, aircraft and other manufacturing industries, which reveal their superior strength, toughness, ductility, fatigue lifetime, superplasticity and formability. This paper presents the various mechanical properties, deformation characteristics and strengthening–toughening mechanisms of laminated metal matrix composites during the loading and deformation process, and that super-high mechanical properties can be obtained by adjusting the fabrication process and structure parameters. In the macroscale, the interface bonding status and layer thickness can effectively affect the fracture, impact toughness and tensile fracture elongation of laminated metal matrix composites, and the ductility and toughness cannot be fitting to the rule of mixture (ROM). However, the elastic properties, yield strength and ultimate strength basically follow the rule of mixture. In the microscale, the mechanical properties, deformation characteristics, fracture behavior and toughening mechanisms of laminated composites reveal the obvious size effect.


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