Ti-8Si-xZr-yY_2O_3合金的摩擦磨损性能研究

Friction and Wear Properties of Ti-8Si-xZr-yY_2O_3 Alloys

选用Ti,Si,Zr单质元素和纳米Y_2O_3粉末高能球磨-冷压烧结制备Ti-8Si、Ti-8Si-0.7Zr、Ti-8Si-1.4Zr和(质量分数,%)4种合金。利用SEM和EDS对烧结合金组织与成分进行分析,测试其硬度和摩擦系数、耐磨性等摩擦磨损性能。结果表明:4种试样烧结之后主要由相、Ti(Si)固溶体及Ti(Si、Zr)固溶体组成。Zr及Y_2O_3是通过改变高硬度的等物相的含量以及固溶体比例而起到弥散强化或固溶强化效果,改变其显微硬度;合金的显微硬度最大,其数值(约13770MPa)比Ti-8Si合金(10200MPa)提高了约35%。Ti-8Si合金(0.365)的摩擦系数最低,但Ti-8Si-1.4Zr(0.504)与相比,添加0.1%Y_2O_3后摩擦系数降低了约26%。添加Zr元素虽然提高了摩擦系数,但可以降低其磨痕宽度,一定程度上改善Ti-8Si合金的耐磨性;同时,合金的磨痕宽度最小,耐磨性最佳,Y_2O_3能够显著提高合金的耐磨性能。4种合金的磨损都以疲劳磨损为主,伴随着磨粒磨损和氧化磨损。

Ti-8Si,Ti-8Si-0.7Zr,Ti-8Si-1.4Zr and（wt%）alloys were prepared by high-energy ball milling and cold-pressure sintering with Ti,Si,Zr and Y2O3 powders as starting materials.Morphologies and phase composition of the sintered samples were analyzed by SEM and EDS,respectively.Their hardness,friction coefficient and wear resistance were also investigated.The results show that the four kinds of samples are mainly composed ofphase,Ti（Si）solid solution and Ti（Si,Zr）solid solution.Zr and Y2O3 function as a dispersion strengthening or solid solution strengthening element through changing the content ofand other phases and the proportion of solid solution,and thus improve the microhardness.Thehas the largest microhardness（13770MPa）,improved by 35%compared with 10200MPa of Ti-8Si.The friction coefficient of Ti-8Si alloy（about 0.365）is minimum;however,the friction coefficient of（about 0.375）decreases by 26% compared with 0.504 of Ti-8Si-1.4Zr.Zr element decreases the wear width of the alloy and improves the wear resistance,although it increases its friction coefficient.alloy has the best wear resistance with minimum wear width,because Y2O3 significantly improves the wear resistance.The wear mechanisms of the four alloys are mainly fatigue wear,accompanied by abrasive wear and oxidation wear.