渗碳时间对TC4钛合金显微组织和强化效果的影响

Effect of carburizing time on microstructure and strengthening effect of TC4 titanium alloy

研究了渗碳工艺对TC4钛合金表面渗碳层组织、组成相及强化效果的影响,特别对不同的渗碳时间对渗碳层厚度、微观组织、相组成及其形成机理进行了深入的探究。结果表明:钛合金表面经渗碳后均形成Ti C陶瓷层+扩散层。表面呈众多胞状结构、小沟槽及纳米微孔的形貌特征,微观组织为众多取向各异、亚微米级的Ti C相晶粒。随着渗碳时间的延长,渗碳层厚度明显增加,经3h渗碳后能获得均匀且致密的Ti C陶瓷层。Ti C陶瓷层硬度高达1195 HV0.2,可有效提高钛合金的表面硬度和耐磨性。

The effects of carburizing layer structure,phase composition and surface peening of TC4 titanium alloy by carburizing process were studied. Especially different carburizing time influence on carburizing layer thickness,microstructure,phase composition and formation mechanism of TC4 titanium alloy carbonized were deeply researched. Experimental results reveal that numerous cellular structures,small grooves and nano micro-pores are formed on TC4 titanium alloy surface. Massive sub micro level Ti C phase grains with different orientations of micro structure are found. With carburizing time prolonging,carburizing layers thickness increases obviously,meanwhile uniform and dense Ti C ceramic layer is obtained at 1050 ℃ carburizing after 3 h. The maximum micro hardness of the Ti C ceramic layer is 1195 HV0. 2,which can effectively improve surface hardness and wear resistance of titanium alloy.