含细长孔ZTC4/TA2钛合金铸件界面熔合效果研究

Interfacial Fusion Effect of ZTC4/TA2 Titanium Castings with Elongated Hole

目的研究镶铸复合机理和钛合金镶铸件的界面熔合效果。方法采用熔模精密铸造和镶铸技术复合的方法制备含细长孔的钛合金铸件,通过酸洗减薄管体壁厚的方式增加镶铸比,探讨镶铸比对铸件组织、界面及熔合率的影响,并分析管体被熔透的临界壁厚值。结果铸件基体组织主要由片状的α相和残余的β晶界构成,管体是片状的魏氏体组织。铸件界面熔合率随着镶铸比增加而增大。在本实验条件下,当铸件为8︰1时,铸件熔合率超过80%;当镶铸比超过15︰1时,铸件内部管体出现熔透现象。结论采用熔模精密铸造和镶铸技术复合的方法可制备含细长孔的钛合金铸件,并且通过减薄管体的方式可提高铸件界面熔合率。

This paper aims to research the recombination mechanism of cast in and the interfacial fusion effect of titanium alloy cast on parts. Investment casting and cast-in technology were adopted to prepare titanium alloy castings with elongated hole. An acid pickling process was introduced to slim the tube wall to increase the inlaying proportion. Effects of inlaying pro-portion on microstructure, interface and fusion rate were discussed along with the critical wall thickness of the melt through pipe body. The results show that, the microstructure of the matrix castings was mainly consisted of flake α and β grain boundary; and the tube body was a sheet widmanstatten structure. The interfacial fusion rate of castings went up with the increase of the inlay-ing proportion. When the inlaying proportion was above 8︰1, the fusion rate of the castings was more than 80%. When the in-laying proportion was above 15︰1, fusion penetration phenomenon happened in the tube body. As a conclusion, titanium alloy castings with elongated hole can be formed by investment casting and cast-in technology, and the interfacial fusion rate of cast-ings can be increased by reducing wall thickness of the tube.