高温氧化膜 Cr_2O_3 和 NiO 中应力松弛过程  

Stresses Relaxation in Cr 2O 3 and NiO during High Temperature Oxidation by in Situ X ray Diffraction

作　　者：杨于兴[1] 卞玉君[1] 

机构地区：[1]上海交通大学国家教委高温材料及高温测试开放实验室

出　　处：《上海交通大学学报》1998年第2期57-61,共5页Journal of Shanghai Jiaotong University

基　　金：国家自然科学基金

摘　　要：用Ｘ射线原位应力测定了高温氧化膜Ｃｒ２Ｏ３和ＮｉＯ中的应力．结果表明，Ｃｒ２Ｏ３／Ｃｒ和ＮｉＯ／Ｎｉ体系氧化膜的生长应力分别为－１．９４９ＧＰａ和６５２ＭＰａ．在冷却过程中，Ｃｒ２Ｏ３／Ｃｒ体系发生很大的应力松弛过程，其主要表现形式为氧化膜翘曲和开裂；而在ＮｉＯ／Ｎｉ体系中，由于ＮｉＯ薄膜具有双层结构承受不同应力状态而获得松弛．The evident character of the stress measurement by in situ X ray diffraction is that sample has no need of rotating during measurement and diffraction peaks are always dedicated by a crystal face(hkl) parallel to sample surface. So the shift of diffraction peaks is completely caused by oxide growth and temperature variation. The measuring precision of diffraction peaks is determined by 2 θ scanning reappearance only(≤0.002°). The results show that the growth stress may reach -1.949 GPa in Cr 2O 3 at 920℃ and 652 MPa in NiO at 910℃. During cooling the thermal stress is superimposed on the growth stress and the appropriate stress relaxation may occur. The stress relaxation in Cr 2O 3 can be achieved by bucking and spallation of oxide scales from morphology analysis. The stress in NiO scales attains to relaxing owing to different stresses in duplex oxide structure.

关 键 词：X射线 热应力 应力松弛 氧化膜 氧化铬 氧化镍 

分 类 号：O484.2[理学—固体物理]