【作者】 高琳；

【导师】 刘怀喜；

【作者基本信息】 郑州大学 ， 车辆工程， 2010， 硕士

【摘要】 本文针对发动机活塞材料的现状和发展要求,通过理论分析与实验研究,制取了一种新型的铝基活塞材料,并对其进行了系统的分析与研究,它的相关性能明显优于常规的活塞材料。用搅拌铸造法制备了三种试样,以ZL101作为基体,在ZL101基体的基础上加入增强成分SiC颗粒、或者在加入SiC的同时也复合添加润滑成分MoS2。在制备前首先对SiC进行了表面高温氧化处理,可在SiC表面产生Si0：薄层,明显改善熔融铝合金基体对SiC颗粒的润湿性,所制备试样的显微组织和SEM表明加入的SiC颗粒和MoS2颗粒均匀弥散在基体内,无团聚现象,试样组织致密,无明显缺陷。说明SiC、MoS2和基体界面结合较好。对试样进行的拉伸试验的结果表明,单纯SiC颗粒增强试样和SiC颗粒增强复合添加MoS2试样较普通ZL101试样均具有更高的强度,复合添加MoS2的试样增幅较低些。对试样进行摩擦磨损试验的结果表明,单纯SiC颗粒增强试样和SiC颗粒增强复合添加MoS2试样较普通ZL101试样均具有更佳的耐磨性能。这是由于单纯SiC颗粒增强试样由于硬相承载机理的作用在短时间干摩擦情形下,磨损速率低。SiC颗粒增强复合添加MoS2试样在摩擦前期,其磨损特征与单纯SiC颗粒增强试样一样,其后由于MoS2在摩擦副表面形成润滑干膜,故磨损速率仍保持较低。更多还原

【Abstract】 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.更多还原