消失模铸造SiC_p/Al复合材料的制备工艺

Preparation Process of SiC/Al Composites with Lost Foam Casting

基于消失模铸造技术,以SiC_p增强铝基复合材料为研究对象,从制备工艺入手,探讨了不同SiC_p含量与粒径的泡沫复合模样充型前后断口磨粒的分布情况及胎体与SiC_p磨粒的结合情况。浇注制备的复合模样,在相同的SiC_p含量下,粒径越小,颗粒数越多,铸铝液无法完全填充复合模样中的泡沫,SiC_p成片剥落,耐磨层厚度减少。但随着粒径增大,颗粒的质量也增加,SiC_p移动的距离变小,有利于固位,耐磨层厚度增加。增大SiC_p含量,耐磨层厚度增加,磨粒在铝液中的固位效果明显提高。从断口形貌来观察,胎体对SiC_p磨粒的把持力较高,胎体与SiC_p磨粒之间结合良好,且不会因为SiC_p含量的提高而发生变化。

The SiC/A1 composites were prepared by the lost foam casting,and distribution of the abrasive grains in fracture and bonding of the carcass and SiC abrasive grains in the foamed composite pattern were discussed with the different content and particle size of SiC before and after the filling.With the smaller SiC particle size and the more SiC particle content,the liquid aluminum cannot completely replace the foam in composite pattern when the composites are poured at the same particle content.So the SiC particles are easily flak off the composites and wear layer thickness is reduced.However,with the increase of SiC particle size and the weight of the particles,the moving distance of SiC particles is reduced,which is conducive to the retention and to increasing wear layer thickness.Increasing in the concentration of SiC particles and the thickness of wear layer,the retention effect of abrasive particles in aluminum liquid is obviously improved.The observation of the fracture morphology reveals that the matrix has high bonding force with SiC particles and it will not be changed with the increase of SiC particle content.