摘要
本文利用感应凝壳熔炼（ISM）法，在金属型中离心浇铸了Ti-48AL-2Cr-2Nb（at，％）合金汽车排气阀，并利用SEM、XRD和EMPA等检测方法对排气阀的表面层结构进行了分析。结果表明，排气阀表面上的铁含量约为0．3wt，％，渗铁层厚度为3μm左右。由于金属型与合金熔体之间的反应，以及铸型的强冷却作用，使得排气阀表面上出现了一定厚度的硬化层，其厚度要远大于渗铁层，这对于提高铸件表面的耐磨性和强度是非常重要的。
Ti -48Al -2Cr- 2Nb （at. % ） alloy exhaust valves have been formed in permanent mold during centrifugal casting process with Induction Skull Melting （ISM） method, and the reaction at TiAl alloy/permanent mold interface have been analyzed by SEM, XRD and EMPA. Results show that the content of Fe on valve surface is about 0. 3wt. % , which thickness is about 31μm. Certain thick hardness layer exists on the cast valve surface because of the reaction at alloy/mold interface and the powerful heat conduction of the mold, which thickness is more larger than that of Fe - diffusion layer. It is very important to improve the resistance and intensity of the cast surface.
出处
《中国材料科技与设备》
2006年第6期91-93,共3页
Chinese Materials Science Technology & Equipment
关键词
金属型
离心浇铸
排气阀
表面层结构
Permanent mold
Centrifugal casting
Exhaust valve
Surface layer
