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通过重复冷轧 Ni/Ti 包覆粉末制备出 Ni/Ti 多层。使用 XRD,SEM,TEM,DSC 和磁性分析方法研究了该多层由恒速升温退火导致的固态非晶化反应。恒速升温退火时多层中首先形成非晶相,当非晶相层厚超过一临界值后,元素间将通过互扩散形成金属间化合物 Ni_3Ti 和 NiTi,最后已形成的非晶相晶化成金属间化合物 Ni_3Ti 和 Ti_2Ni。首次利用扩散控制的层长大机制和瞬时形核模型,计算了恒速升温退火处理时多层中非晶层长大厚度和金属间化合物的形成温度。
Ni / Ti multilayers were prepared by repeated cold rolling Ni / Ti coated powders. The XRD, SEM, TEM, DSC and magnetic analysis were used to study the solid state amorphization reaction of the multilayers by constant temperature annealing. When the amorphous layer thickness exceeds a critical value, the intermetallics will form intermetallic compounds Ni_3Ti and NiTi through interdiffusion, and finally the formed amorphous phase will be crystallized into metal Compounds Ni_3Ti and Ti_2Ni. For the first time, diffusion-controlled layer growth mechanism and instantaneous nucleation model were used to calculate the growth of amorphous layer and the formation temperature of intermetallics during constant temperature annealing.