Investigation of Pt-Dy co-doping effects on isothermal oxidation behavior of (Co,Ni)-based alloy

作     者：兰昊 张伟刚 杨志刚 

作者机构：State Key Laboratory of Multi-phase Complex SystemsInstitute of Process EngineeringChinese Academy of Sciences State Key Laboratory of New Ceramics and Fine ProcessingDepartment of Materials Science and EngineeringTsinghua University 

出 版 物：《Journal of Rare Earths》 (稀土学报（英文版）)

年 卷 期：2012年第30卷第9期

页      面：928-933页

核心收录：

学科分类：08[工学] 080502[工学-材料学] 0805[工学-材料科学与工程（可授工学、理学学位）] 

基　　金：Project supported by National Natural Science Foundation of China (51071089) 

主　　题：alloy oxidation platinum dysprosium rare earths 

摘      要：A Co32Ni21Cr8Al0.6Y （wt.%） alloy with and without doping 3 wt.% platinum, or co-doping 3 wt.% platinum and 0.1 wt.% dys- prosium was produced by arc melting. The hardness of both base alloy and composition-modified alloy was measured by using a Vickers hardness tester. Isothermal oxidation tests at 1000 ℃ in static air atmosphere were conducted to assess the isothermal oxidation behavior of the alloys. The microstructure and composition of the tested alloys before and after oxidation were investigated by means of X-ray diffraction （XRD）, field emission-scanning electron microscopy （FE-SEM） equipped with energy dispersive spectroscopy （EDS） and back scatter detec- tor. Results showed that platinum had significant influence on microstructure of the tested alloy by the formation of β-（Ni,Pt）AI phase. Addi- tion of 3 wt.% platinum could slightly increase the hardness of the tested alloy. Platinum accelerated phase transformation of alumina from metastable θ-Al2O3 to stable α-Al2O3 and suppressed the consumption of 13-phase. Co-doping both 3 wt.% platinum and 0.1 wt.% dysprosium induced the fastest transformation of θ- to α- alumina and the formation of a fine-grained oxide scales. The most effective reduction of oxida- tion rate was achieved by the Pt-Dy co-doping effects.