Investigation of Pt-Dy co-doping effects on isothermal oxidation behavior of （Co,Ni）-based alloy
来源期刊：Journal of Rare Earths2012年第9期
论文作者：兰昊 张伟刚 杨志刚
文章页码：928 - 933
摘 要：A Co32Ni21Cr8Al0.6Y （wt.%） alloy with and without doping 3 wt.% platinum, or co-doping 3 wt.% platinum and 0.1 wt.% dysprosium 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 detector. Results showed that platinum had significant influence on microstructure of the tested alloy by the formation of β-（Ni,Pt）Al phase. Addition of 3 wt.% platinum could slightly increase the hardness of the tested alloy. Platinum accelerated phase transformation of alumina from metastable θ-Al 2 O 3 to stable α-Al 2 O 3 and suppressed the consumption of β-phase. Co-doping both 3 wt.% platinum and 0.1 wt.% dysprosium induced the fastest transformation of θto αalumina and the formation of a fine-grained oxide scales. The most effective reduction of oxidation rate was achieved by the Pt-Dy co-doping effects.
兰昊1，张伟刚1，杨志刚2
1. State Key Laboratory of Multi-phase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences2. State Key Laboratory of New Ceramics and Fine Processing, Department of Materials Science and Engineering, Tsinghua University
摘 要：A Co32Ni21Cr8Al0.6Y （wt.%） alloy with and without doping 3 wt.% platinum, or co-doping 3 wt.% platinum and 0.1 wt.% dysprosium 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 detector. Results showed that platinum had significant influence on microstructure of the tested alloy by the formation of β-（Ni,Pt）Al phase. Addition of 3 wt.% platinum could slightly increase the hardness of the tested alloy. Platinum accelerated phase transformation of alumina from metastable θ-Al 2 O 3 to stable α-Al 2 O 3 and suppressed the consumption of β-phase. Co-doping both 3 wt.% platinum and 0.1 wt.% dysprosium induced the fastest transformation of θto αalumina and the formation of a fine-grained oxide scales. The most effective reduction of oxidation rate was achieved by the Pt-Dy co-doping effects.
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