Research Of The New Al Matrix Composites Piston Material

According to the present situation and developmental requirement of engine pistons material, the author of this paper made a new type of new piston material based on aluminum matrix composites on the basis of theoretical analysis and experimental research.The results of the systematical study indicated that the related performance of the new materical was superior to that of the qeneral piston material obviously.Three samples prepared by stir-casting method have been investigated.The first sample regards ZL101 as matrix,the second one is blended with SiC particles in the ZL101,the last one is combined with enhancement ingredient SiC particles and the lubrication ingredient MoS2 particles in the ZL101 at the same time.The results showed that the wet ability of molten aluminum alloy solution to SiC particles is obviously improved after high heat treatment because of the thin layer SiO2 on the surface of SiC particles.the microstructure and SEM of the sample indicated that the SiC particles and MpS2 particles were evenly distributed and preferably combined without SiC particles agglomerates in the composites.There are not major defects in the samples with compact structure.The results indicated that the viscidity between SiC,MpS2 and substrate is well.The stretching test showed that the strength of SiC particle reinforced sample and SiC and MoS2 particle reinforced composite sample are higher than that of ZL101 matrix and the strength of SiC and MoS2 particle reinforced composite sample has a slow graining rate.The friction and wear characteristics of composite of the sample have been studied.The results indicated that the wear-resisting performance of SiC particle reinforced sample.SiC and MoS2 particle reinforced composite sample were superior to that of ZL101,for there existed a slow friction and wear speed in a short period resulting from hard phase load-bearing mechanism.The friction and wear characteristics of the three sample is the same in the previous experiments,but the wear rate of SiC particle reinforced sample is keeping slow in the latter experiment owing to the formation of a MoS2 dry film lubrication in friction surface.