摘要
采用热重分析(TG)、电子探针及化学分析等法研究了Ag-0.5Ce合金在400～900℃的氧化气氛中的氧化及挥发特性,以及Ag、Ce、O_2的相互作用。结果表明在热处理中同时存在氧化及挥发过程,低温下氧化由晶界扩散控制,高温下体扩散成为主要机制。Ag、Ce、O_2的面分布、线分布及含量变化说明热处理中Ce由合金内部向外扩散,一部份与向内扩散的O_2在试样表层形成CeO_2,另一部份在表面挥发,O_2除和Ce作用外,还有相当量溶于Ag基体。在Ag中添加Ce使O_2的扩散速度加快。
The oxidation and volatilization of Ag-0.5wt % Ce alloy in oxidizing atmosphere a(?) temperaturc of 400 to 900℃, and thc interaction among Ag, Ce and O_2 have been studied by the methods of the thermal gravimetric analysis (TG), electron probe and chemical analysis. The results of TG show that there exist oxidation and volatilization simultancously in the high temperature treatment. At relatively low temperature the oxidation is controlled by the grain boundaries diffusion, and at higher temperature the volume diffusion becomes the main mechanism of oxidation. The area and line distributions, the changes of the contents of Ag, Ce and O_2 indicated that the cerium diffuses from the interior of the sample to the surface. At the surface zone, some of the cerium is combined with O_2 to form CeO_2. The oxygen diffuses from the sample surface toward the interior, part of which is resolved in the matrix of α-Ag. Part of the cerium is volatilized from the surface. The diffusion rate of O_2 in the alloy is speedcd by the addition of Ce.
出处
《贵金属》
CAS
CSCD
北大核心
1992年第1期24-35,共12页
Precious Metals
关键词
高温
氧化试验
挥发
银铈合金
Silver base alloy
Cerium additions
High temperature oxidation test
Volatilization
