压痕法确定热障涂层蠕变参数  

Determination of Creep Parameters of the Thermal Barrier Coatings Using an Impression Creep Test

作　　者：闫五柱 温世峰 刘军 岳珠峰 

机构地区：[1]NW Polytech Univ, Dept Engn Mech, Xian 710129, Peoples R China

出　　处：《稀有金属材料与工程》2010年第10期1829-1834,共6页Rare Metal Materials and Engineering

基　　金：国家自然科学基金(10472094);高等教育博士点专项研究基金(N6CJ0001)

摘　　要：对单相半无限大材料和涂层/基体材料系统分别进行平头压痕蠕变试验的有限元模拟。对于每一种材料系统,分别考虑不同尺寸的压头,研究压头尺寸对涂层/基体材料系统压痕蠕变应力指数的影响规律。通过对有限元计算结果的分析,提出一个考虑压头尺寸的权重函数来量化涂层和基体对涂层/基体系统压痕蠕变指数的影响程度。基于此权重函数,提出一个确定涂层蠕变指数的分析法。最后根据压头尺寸对涂层/基体系统压痕蠕变指数的影响规律,提出确定涂层蠕变指数的外推法。An extensive accurate finite element (FE) analysis of the impression creep test was performed for two material systems, i.e. a single phase half infinite system and a coating/substrate system. For each case, the FE analysis was carried out for different classes of punch sizes aimed to develop methods to separate creep properties of a coating from a coating/substrate system. The study emphasis was placed on understanding how the punch size influenced the impression creep exponent of a certain coating/substrate system. A weight expression was proposed to quantify the coating's and the :substrate's contributions to the impression creep exponent of the coating/substrate system. The results of finite element analysis show that the value of the weight expression exhibits a good power-law dependence on the radius of the punch for a certain coating/substrate system. The weight function proposed allows developing an analytic approach to separate coating's creep exponent from a coating/substrate system. Then a numerical approach including procedures of fitting the curve of n vs R/T(c) and extrapolating to R=0 was put forward to determine the coating's creep exponent. Both of the results obtained by the two methods agree reasonably well with the input FE model.

关 键 词：压痕法 热障涂层 蠕变参数 Creep Test 材料系统 变指数 基体系统 影响规律 压头 权重函数 有限元模拟 压痕蠕变试验 蠕变应力指数 涂层和基体 影响程度 计算结果 分析法 外推法 半无限 平头 

分 类 号：TG174.4[金属学及工艺—金属表面处理]