摘要
针对钛合金熔模精密铸造,选用相同的低成本黏结剂,采用氧化锆和刚玉2种不同的氧化物陶瓷型壳材料进行了钛合金熔模精密铸造氧化物陶瓷型壳的制备。采用Ti-6Al-2Zr-1Mo-1V(BT20)、Ti-6Al-4V(TC4)、纯钛(TA2)3种典型牌号合金,使用LZ-5型离心铸钛机进行了钛合金的熔炼和浇注,研究了氧化物陶瓷型壳材料对钛合金组织形态的影响。对于3种不同合金,不同的型壳材料浇注出的合金组织形态有很大的差异,ZrO2作为粉料浇注出的合金组织要比以Al2O3为粉料的细小。对钛合金与型壳的界面反应进行了元素的线扫描分析,得到了ZrO2和Al2O3与钛液的反应特性。以刚玉作为材料的型壳,与钛液的反应比较明显,而且形成连续的反应层,厚度达30～40μm,且厚度分布比较均匀;以ZrO2为粉料的型壳元素Zr的扩散距离很短,约为Al的1/3,宏观表现反应层窄小且不连续。
Special mould shells for precision-casting titanium alloys were prepared with the same binder and different mould shell materials of ZrO2 and Al2O3.Ti-6Al-2Zr-1Mo-1V（BT20）,Ti-6Al-4V（TC4） and pure titanium（TA2） were melt and cast into the special mould shells with an LZ-5 centrifugal casting machine.The effects of mould shell materials on the microstructure of the titanium alloys were studied.The results showed that the microstructures of the titanium alloys prepared with different mould shells were different specially.The microstructure of the alloys prepared with the ZrO2 mould shell was finer than that with the Al2O3.The interface reaction of the titanium alloys with the mould shells was investigated by means of line scanning.Compared with the ZrO2 mould shell,the reaction between the Al2O3 mould shell and the titanium alloys was severe,the reaction layers were continuous and the thickness of the reaction layers was about 30 to 40 μm.The reaction layers of the ZrO2 mould shell were thinner and their thickness was about 1/3 as large as that of the Al2O3 mould shell.
基金
高等学校博士学科点专项科研基金资助项目(200802130014)
哈尔滨工业大学优秀青年教师培养计划资助项目(HITQNJS2009022)
关键词
钛合金
精密铸造
氧化物陶瓷
显微组织
界面反应
titanium alloys
precision casting
oxides ceramics
microstructure
interface reaction
