SiC_p表面改性对Al-Si基复合材料耐磨性的影响

Effects of Surface Modification of SiCpon the Wear-resistance of Aluminium-silicon-based Composites

为了改善SiC颗粒(SiC_p)与Al-Si基体界面的润湿性,对SiC_p进行了高温氧化、NaOH溶液腐蚀、K2ZrF6溶液涂覆表面改性处理,通过粉末冶金法制备了不同表面改性状态的SiC_p增强Al-Si基复合材料。研究表明,随氧化时间的增加,SiC_p表面SiO2层的厚度增加。经过NaOH溶液腐蚀后SiC_p表面变粗糙,K2ZrF6饱和溶液处理后SiC_p表面存在一层涂层;随SiC_p氧化时间延长,试样的密度、硬度及耐磨性先增加后减小;SiC_p氧化10h时,试样磨损量最低,与未改性的SiC_p相比,磨损量降低了40%。

SiC_pwas modified by high temperature oxidation,NaOH solution corrosion and K2ZrF6 solution coating to understand effects of modification of SiC_p on the wear-resistance of aluminium-siliconbased composites,and the wear-resistance of aluminium-silicon-based composite reinforced by modified SiC_p was investigated.The phase,surface morphology,hardness and wear resistance of the composites were tested by X-ray diffractometer（XRD）,scanning electron microscope（SEM）,Brinell hardness tester and ML-10 type wear testing machine,respectively.The results show that the thickness of SiO2 at the surface of SiC_pis increased with increasing in oxidation time,and the surface of SiC_pbecome coarse after corrosion by NaOH solution,meanwhile,a coating exists on the surface of SiC_pafter treated by K2ZrF6 solution.In addition,the density,hardness and wear resistance of the samples are increased firstly and then decreased with oxidation time increase.Compared with sample reinforced by unoxidized SiC_p,the wear rate is decreased by 40%for sample reinforced by SiC_poxidized at 1 100 ℃for 10 h.