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利用粉末冶金/放电等离子烧结技术制备了添加Mo、Cu、Ag和Nb的Ti_3SiC_2基复合材料,并察了Ti_3SiC_2/Mo、Ti_3SiC_2/Cu、Ti_3SiC_2/Ag和Ti_3SiC_2/Nb复合材料的相态组成和摩擦学性能。研究表明,金属相的添加会造成Ti_3SiC_2基体不程度的分解,生成TiC、Si和钛硅化合物,其中Mo和Cu与Ti_3SiC_2中化学反应活性较高的Si生成Mo_5Si_3、(Ti_(0.8)Mo_(0.2))Si_2、MoSi_2和Cu3Si等,而Ag和Nb未发生反应,在复合物中以金属单质相存在;四种复合物的摩擦学性能均优于纯Ti_3SiC_2,其中Ti_3SiC_2/Ag和Ti_3SiC_2/Nb复合物的抗磨损性能较好;晶粒拔出脱落造成的磨粒磨损是纯Ti_3SiC_2及其复合材料的主要磨损机制,复合材料中TiC及金属硅化物等硬质相在摩擦过程中定扎了周围的Ti_3SiC_2软基体,抑制了摩擦过程中晶粒的拔出脱落,但多物相并存又使得复合物晶间结合强度降低,导致磨损率提高;复合物中金属单质Ag和Nb的存在起到了一定程度的晶间强化作用;材料转移也是造成复合物磨损率高的一个原因。
Ti_3SiC_2 matrix composites with Mo, Cu, Ag and Nb additions were prepared by powder metallurgy / spark plasma sintering. The phase composition and friction of Ti_3SiC_2 / Mo, Ti_3SiC_2 / Cu, Ti_3SiC_2 / Ag and Ti_3SiC_2 / Learn performance The results show that Ti_3SiC_2 matrix can be decomposed to TiC, Si and Ti_xSi_4 by adding the metal phase. Mo and Cu with Ti and Si_3SiC_2 have higher chemical reactivity, and Mo_5Si_3 and Ti_ (0.8) Mo_ (0.2) )) Si 2, MoSi 2 and Cu 3 Si, etc. However, Ag and Nb did not react with each other and existed as metal element in the composite. The tribological properties of the four composites were better than that of pure Ti 3 SiC 2, in which Ti 3 SiC 2 / Ag and Ti 3 SiC 2 / The abrasion resistance of pure Ti_3SiC_2 and its composites is the main wear mechanism of the pure Ti_3SiC_2 and its composites. The hard phases of the TiC and the metal silicides in the composites are fixed around the periphery during the rubbing process Ti3SiC2 soft matrix inhibited the pull-out of the grains in the process of friction, but the coexistence of multi-phases reduced the bonding strength between the grains and led to the increase of the wear rate. The presence of Ag and Nb in the composites A certain degree of intergranular strengthening; material transfer is also a reason for the high wear rate of the composite.