钛铝基合金离子碳氮共渗及其耐磨性的研究

为提高TiAl基合金的耐磨性及抗高温氧化性,利用渗氮在TiAl基合金表面形成氮化物,以提高耐磨性;渗碳形成致密且与基体结合牢固的碳化物层,提高抗高温、抗氧化性;将二者结合,采用辉光离子碳氮共渗的方法,研究了渗层的相结构组成、不同工艺参数对TiAl基合金离子碳氮共渗后渗层厚度以及表面硬度和耐磨性的影响.结果表明:TiAl基合金共渗层是由碳氮化合物层与过渡层组成的复合相结构;随共渗温度的升高和时间的延长,渗层厚度增加;与未经共渗处理的试样相比,表面硬度及耐磨性显著提高.X射线衍射结果显示,渗层主要由TiC,TiN,AlTi3,Al2O3等组成.

Ion Carbonitriding of TiAl Based Alloy and Its Wear Resistance

Nitriding and carbonizing were combined to increase the surface wear resistance and high temperature oxidation resistance of TiAl based alloy. Thus glowing ion carbonitriding was used to modify the TiAl based alloy surface. The correlation among the phase structure and processing parameters and the thickness, hardness, and antiwear behavior of the carbonitriding layer on TiAl based alloy was studied. The phase composition of the carbonitriding layer was analyzed using X-ray diffraction. The results showed that the carbonitriding layer was composed of carbonitride and transition layer compound. The thickness of the carbonitriding layer gradually increased with increasing process temperature and time. Moreover, the surface hardness and wear resistance of the TiAl based alloy were greatly increased by ion carbonitriding, which was attributed to the formation of the hard ceramic phases including TiC, TiN, AlTi_3, Al_2O_3, in the carbonitriding layer.