Fabrication And Microstructures And Thermal Physical Property Of SiCp/Al Electronic Packing Materials Made Through Subsonic Flame Spraying Technique

Sprayed SiCp/Al composites with high SiC volume fraction were fabricated by subsonic flame spraying technique, which met the demand of electronic packing materials(EPMs). The influences of ball milling process on the AlSiC complex powder were discussed, the effects of spraying technology on the microstructures of SiCp/Al EPMs were investigated, the roles of hot pressing in microstructures and thermal physical properties of sprayed SiCp/Al EPMs were analyzed. The thermal expansion behaviors and thermal conductivity of SiCp/Al EPMs were determined. The ball milling and spraying and hot pressing processes were optimized. The study laid the first stone for application of sprayed SiCp/Al EPMs in the future.The results show that, the longer ball milling time, the finer and more uniform the SiC and Al powder distribute; relatively time, running speed of ball milling is more helpful to the homogeneity and fine; with The mass ratio between the ball to powder increasing, the complex powder get finer and finer, and more Al coating SiC particles.The results demonstrate also that, the SiC volume fraction in the sprayed SiCp/Al EPMs increases with spraying distance decreasing and acetylene pressure increasing; with compressed air pressure decreasing, the rate and probability of SiC deposit drop.The results present further that, the density of sprayed SiCp/Al EPMs rises and gets a certain value with temperature and temperature increasing. The microstructures get more even and densified after hot pressing.The results revealed that the microstructures of the composite were uniform and dense. At the same time, the interfaces between SiC particle and Al bonded well; the XRD test proves that SiC and Al were main phases in the flame sprayed composite, and a few Al2O3 was found in the composite. a few nano-grain and particle were seen in the flame sprayed composites; the cavities and dislocations and pores are main defects in the aluminum matrix, the dislocations and stacking faults and a few of fine cracks in the SiC particles. Certain interface relationships exists between SiC and Al matrix.The results proves that, the thermal expansion coefficients of SiCp/Al EPMs decreases with SiC volume fraction and pores increasing and temperature decreasing. Compared to as-sprayed, the thermal expansion coefficients and thermal conductivities of SiCp/Al EPMs all increase obviously after hot pressing, moreover thermal conductivities of SiC EPMs decreases firstly with SiC volume fraction increasing after hot pressing. But it will increase, when SiC volume fraction of SiCp/Al EPMs is over 40%.