Growing kinetics and structural characterization of oxide film formed on La-doped Co-40Cr alloy

The isothermal and cyclic oxidizing kinetics of Co-40Cr alloy and its lanthanum ion-implanted samples were studied at 1000℃ in air by thermal-gravity analysis (TGA). Scanning electronic microscopy (SEM) and transmission electronic microscopy (TEM)) were used to examine the oxidized film's morphology and the structure after oxidation. Secondary ion mass spectrum (SIMS) method was used to examine the binding energy change of chromium caused by La-doping and its in?uence on formation of Cr2O3 film. Laser Raman spectrum was used to examine the tress changes within oxidized films. It was found that lanthanum implantation remarkably reduced the isothermal oxidizing rate of Co-40Cr and improved the anti-cracking and anti-spalling properties of Cr2O3 film. The reasons were that the implanted lanthanum reduced the grain size and internal stress of Cr2O3 oxide, increased the high temperature plasticity of oxidized film. Lanthanum mainly existed in the outer surface of Cr2O3 film in the forms of fine La2O3 and LaCrO3 spinel particles.     

注镧Co-Cr合金表面氧化膜生长规律与微观结构表征

采用热重分析(TGA)方法研究了离子注镧对Co-40Cr合金在1000℃空气中的恒温氧化和循环氧化行为的影响. 用扫描电镜(SEM)和透射电镜(TEM)对表面氧化膜的微观形貌和结构进行了研究. 用二次离子质谱(SIMS)对合金表面元素铬结合能的变化情况以及氧化膜中元素镧的深度分布进行了测试, 并用激光拉曼谱(Raman)对掺杂镧引起的氧化膜内应力改变进行了测量研究.结果表明, 离子注镧后Co-40Cr合金在1000℃空气中的恒温氧化速率显著降低, 表面Cr₂O₃ 关键词： 离子注入 镧 拉曼谱 二次离子质谱     

离子注钇对镍900℃高温氧化行为及氧化膜性能的影响研究

采用热重分析对纯镍及其表面离子注钇样品在900℃空气中的恒温氧化动力学规律进行了研究.用扫描电子显微镜和透射电子显微镜对含钇和不含钇氧化膜的微观形貌及结构进行了观测.用声发射方法对氧化膜在恒温生长阶段和空冷阶段的开裂与剥落进行了实时监测，根据相应的氧化膜开裂模型，对声发射信号在时域和数域上的分布情况进行了分析.结果表明离子注钇显著降低了镍的恒温氧化速率，提高了表面NiO膜的抗开裂和抗剥落性能.离子注钇提高镍抗氧化性能的原因主要是钇细化了表面NiO膜的晶粒、提高了氧化膜的高温塑性和蠕变能力，并显著降低了Ni/NiO界面缺陷的数量和大小. 关键词： 高温氧化 应力 声发射 离子注入     

注镧Co-Cr合金表面氧化膜生长规律与微观结构表征

采用热重分析(TGA)方法研究了离子注镧对Co-40Cr合金在1000℃空气中的恒温氧化和循环氧化行为的影响. 用扫描电镜(SEM)和透射电镜(TEM)对表面氧化膜的微观形貌和结构进行了研究. 用二次离子质谱(SIMS)对合金表面元素铬结合能的变化情况以及氧化膜中元素镧的深度分布进行了测试, 并用激光拉曼谱(Raman)对掺杂镧引起的氧化膜内应力改变进行了测量研究.结果表明, 离子注镧后Co-40Cr合金在1000℃空气中的恒温氧化速率显著降低, 表面Cr₂O₃