低弹性模量钛铌锆锡合金铸件表面反应层结构的研究

A surface reacted layer study of Ti-Nb-Zr-Sn alloy after dental casting

目的:观察铸模温度对钛铌锆锡(Ti-Nb-Zr-Sn)合金铸件表面反应层结构的影响。方法:在两种铸模温度下(室温,300°C)进行合金的铸造。对铸件表面反应层的结构及显微硬度进行测试;采用SEM下的能谱分析(EDS)对铸件抛光前后的表面元素成份进行对比研究。结果:随着铸模温度的提高,Ti-Nb-Zr-Sn合金铸件表面反应层的厚度增加,表面硬度值增大。组织金相显示铸件表面反应层结构可分为3层。铸件表面抛光前元素Si、A1含量较高,抛光后则明显减少。且随着铸模温度的提高,Si的扩散深度及渗透量均有所增加。结论:为了减少Ti-Nb-Zr-Sn合金铸件表面反应层的厚度,应尽量降低铸模温度,同时应选择无Si的包埋材料。

Objective.To investigate the influence of the mold temperature on the surface reacted layer of Ti-Nb-Zr-Sn alloy castings, Method： Ti-Nb-Zr-Sn alloy was casted at two mold temperatures（room temperture, 300 ℃ ）. The roughness and the microstructure of the surface reacted layer of the castings was studied . The surface atomic composition of the castings before and after polished was determined by EDS（Energy Dispersive Spectrometer）, Result.The surface roughness of the castings was increased significantly with the mold temperature increasing, At a higher mold temperature the hardness of the reactive layer was increased, From the micrograph of the Ti-Nb-Zr-Sn alloy casting, the surface reacted layer could be divided into three different layers, Higher level of element of Al, Si were found at the surface of the castings before polished, and were found reduced obviously after polished,Tbe higher the mold temperature during casting, the deeper the Si permeating. Conclusion：The mold temperature is one of the major factors influencing to casting quality. In order to reduce the surface reacted layer of Ti-Nb-Zr-Sn alloy castings, the lower mold temperature and the investment without Si should be chosen.