The Al/Si/SiC composites with medium volume fraction for electronic packaging were fabricated by gas pressure infiltration.On the premise of keeping the machinability of the composites,the silicon carbide particles,wh...The Al/Si/SiC composites with medium volume fraction for electronic packaging were fabricated by gas pressure infiltration.On the premise of keeping the machinability of the composites,the silicon carbide particles,which have the similar size with silicon particles（average 13 μm）,were added to replace silicon particles of same volume fraction,and microstructure and properties of the composites were investigated.The results show that reinforcing particles are distributed uniformly and no apparent pores are observed in the composites.It is also observed that higher thermal conductivity（TC） and flexural strength will be obtained with the addition of SiC particles.Meanwhile,coefficient of thermal expansion（CTE） changes smaller than TC.Models for predicting thermal properties were also discussed.Equivalent effective conductivity（EEC） was proposed to make H-J model suitable for hybrid particles and multimodal particle size distribution.展开更多
<div style="text-align:justify;"> The constitutive behaviors of the sintered reactive material PTFE/Al/Si, one new formulation proposed by the author, were studied systematically and found it appears s...<div style="text-align:justify;"> The constitutive behaviors of the sintered reactive material PTFE/Al/Si, one new formulation proposed by the author, were studied systematically and found it appears strain-harden, stain-rate harden and temperature-soften effects, so it is more appropriate to describe the mechanical behavior with the Johnson-Cook model. With the static and dynamic experimental results and using the nonlinear fitting method, the mechanical and physical parameters in the Johnson-Cook model were determined, which supply one basis for the future numerical simulation study. </div>展开更多
High reinforcement content Al/Si composites were fabricated by pressure infiltration technology. The composites are free of porosity and silicon particles distribute uniformly in the composites. The properties and fra...High reinforcement content Al/Si composites were fabricated by pressure infiltration technology. The composites are free of porosity and silicon particles distribute uniformly in the composites. The properties and fracture behavior of the composites were studied. The composites fracture is aroused by silicon brittle fracture and extends to the composites inward through the metallurgical structure and fracture analysis. The thermal expansion behavior of the composites was investigated by a high-precision thermomechanical analyzer,and compared with the predictions of theoretical model. The mean linear coefficient of thermal expansion(CET) of Al/Si composites ranges from 8×10-6 to 10×10-6/ ℃ and decreases with increasing silicon volume fraction.展开更多
基金Project (60776019) supported by the National Natural Science Foundation of ChinaProject (61-TP-2010) supported by the Research Fund of the State Key Laboratory of Solidification Processing (NWPU),China
文摘The Al/Si/SiC composites with medium volume fraction for electronic packaging were fabricated by gas pressure infiltration.On the premise of keeping the machinability of the composites,the silicon carbide particles,which have the similar size with silicon particles（average 13 μm）,were added to replace silicon particles of same volume fraction,and microstructure and properties of the composites were investigated.The results show that reinforcing particles are distributed uniformly and no apparent pores are observed in the composites.It is also observed that higher thermal conductivity（TC） and flexural strength will be obtained with the addition of SiC particles.Meanwhile,coefficient of thermal expansion（CTE） changes smaller than TC.Models for predicting thermal properties were also discussed.Equivalent effective conductivity（EEC） was proposed to make H-J model suitable for hybrid particles and multimodal particle size distribution.
文摘<div style="text-align:justify;"> The constitutive behaviors of the sintered reactive material PTFE/Al/Si, one new formulation proposed by the author, were studied systematically and found it appears strain-harden, stain-rate harden and temperature-soften effects, so it is more appropriate to describe the mechanical behavior with the Johnson-Cook model. With the static and dynamic experimental results and using the nonlinear fitting method, the mechanical and physical parameters in the Johnson-Cook model were determined, which supply one basis for the future numerical simulation study. </div>
文摘High reinforcement content Al/Si composites were fabricated by pressure infiltration technology. The composites are free of porosity and silicon particles distribute uniformly in the composites. The properties and fracture behavior of the composites were studied. The composites fracture is aroused by silicon brittle fracture and extends to the composites inward through the metallurgical structure and fracture analysis. The thermal expansion behavior of the composites was investigated by a high-precision thermomechanical analyzer,and compared with the predictions of theoretical model. The mean linear coefficient of thermal expansion(CET) of Al/Si composites ranges from 8×10-6 to 10×10-6/ ℃ and decreases with increasing silicon volume fraction.
