Ti/Ni多层复合材料界面扩散行为的研究

Study on the Diffusion Behavior of Ti/Ni Multilayer Composites

摘要:

本文针对累积叠轧5道次制备的Ti/Ni多层结构复合材料试样进行热处理，采用光学显微镜和扫描电镜分析方法，对复合材料的显微组织、界面结构和扩散反应层厚度等进行观察分析，结合动力学理论研究了Ti/Ni界面的扩散行为。研究结果表明：试样经过累积叠轧5道次轧制后，Ti/Ni界面未发生扩散；在(550 ℃-750 ℃)×(0.5 h-8 h)热处理后，Ti/Ni界面发生扩散，扩散层厚度与保温时间呈幂函数关系，与加热温度呈指数关系；随着热处理温度的升高，Ti-Ni扩散层的生长方式由650 ℃以下的体扩散控制逐渐转变为晶界扩散控制。通过计算和验证得到采用累积叠轧5道次制备的Ti/Ni多层复合材料的Ti/Ni界面固相反应层生长动力学方程为：y=1.7043*104*exp(-78202/RT) *t1.2009-0.0008T。

Abstract:

In this paper, the sample of Ti/Ni multilayered composites fabricated by 5 cycles ARB were treated with different heat treatment. The microstructure, interface structure and the thickness of Ti/Ni interface diffusion layer were analyzed by the optical microscope(OM) and scanning electron microscopy (SEM) analysis technology, combined with the dynamic theory to study the diffusion behavior of Ti/Ni interface. The results show that the Ti/Ni interface did not diffusion during accumulative roll bonding processes. After heat treatment with(550 ℃-750 ℃)×(0.5 h-8 h), the Ti/Ni interface occurred diffusion, the thickness of diffusion layer was power function within the experimental time, the thickness is exponential function relation with temperature. With the increase of heat treatment temperature, the growth of Ti - Ni diffusion layer was controlled by the body diffusion under 650 ℃ gradually transformed into grain boundary diffusion controlled. Through the calculation and verification we can get the dynamics equation of reaction layer growth of Ti/Ni interface of Ti/Ni multi-layer structure composite material produced by 5 cycles accumulative roll bonding is:y=1.7043*104*exp(-78202/RT) *t1.2009-0.0008T .