稀土元素Y对TiNi形状记忆合金基体渗铝涂层恒温氧化行为的影响  

Effect of Rare Earth Element Yttrium on the Isothermal Oxidation Behavior of Aluminide Coatings on Ti-Ni Shape Memory Alloys

作　　者：徐家文[1] 刘爱莲[1] 王永东[1] 周月波[1] 

机构地区：[1]黑龙江科技大学,黑龙江哈尔滨150022

出　　处：《稀有金属材料与工程》2016年第6期1413-1418,共6页Rare Metal Materials and Engineering

基　　金：National Natural Science Foundation of China （51201062, 51371078）

摘　　要：采用粉末法，在不同Y含量的TiNi形状记忆合金基体上制备了650℃渗铝涂层，并对Y影响涂层的形成以及涂层在700℃恒温氧化性能进行了研究。结果表明：渗铝涂层由外层TiAl3和内层NiAl3构成，涂层的生长主要由Al的内扩散控制。当Y含量低于1at%时，稀土元素Y的添加促进TiAl3外层的生长，抑制NiAl3 内层的生长。恒温氧化实验表明：添加0.5at%Y能明显降低渗铝涂层的氧化速度，但添加1 at%Y和5 at%Y却加速涂层的氧化。并对Y影响涂层的形成以及恒温氧化性能进行了分析。Ti-Ni shape memory alloys with and without Y addition were aluminized at 650 ℃ using a pack-cementation method. The influences of various amounts of Y additions on the microstructure and the isothermal oxidation behaviors of aluminide coatings in air at 700 ℃ were investigated. The results show that aluminide coatings exhibit double layer structure, and the aluminization process is mainly controlled by the inner diffusion orAl. The Y addition promotes the growth of outer TiA13 layer, but it retards the growth of inner NiA13 layer when Y content is lower than lat%. Isothermal oxidation results indicate that the scale growth rate is significantly reduced when the Y addition is 0.5at%. In contrast, the oxidation rate of Ti-Ni alloy is increased when lat% Y and 5at% Y are added, especially 5at% Y addition. The effect of Y element on the coating formation and the coating oxidation behavior was discussed.

关 键 词：TINI形状记忆合金 铝化物 恒温氧化 活性元素效应 稀土 

分 类 号：TG174.4[金属学及工艺—金属表面处理] TG139.6[金属学及工艺—金属学]