摘要
Ｎｉ衬底用粉末包装法先扩散Ａｌ再扩散Ｃｒ时，在Ａｌ—Ｃｒ扩散层内产生了孔穴。它形成的原因是：活化剂ＮＨ４Ｃｌ加热分解时生成ＨＣｌ气体，与已形成扩散层中的Ａｌ作用，使其从扩散层中逃逸，而在原来Ａｌ的位置上产生了孔穴。含有孔穴的Ａｌ－Ｃｒ扩散层的抗氧化能力明显降低。
Aluminum-chromium diffusion coatings on pure nickel substrate were formed by two-step pack cementation process. It was found that existed many voids in the coatings which were formed by first aluminizing and then chromizing. It could be understood that aluminum in the coatings reacted with HCL gas decomposed from activator NH4CL and formed ACL3,which evaporated and resulted in formation of the voids.Oxidation resistance of Al-Cr coating with these voids was reduced signigicantly.
出处
《北京科技大学学报》
EI
CAS
CSCD
北大核心
1996年第S2期42-45,共4页
Journal of University of Science and Technology Beijing
基金
冶金部腐蚀-磨蚀与表面技术开放研究实验室资助
