Ni₃Al-Ni₃V合金的室温摩擦磨损性能

Friction and Wear Properties of Ni₃Al-Ni₃V Alloy at Room Temperature

摘要: 为研究Ni₃Al-Ni₃V合金的室温磨损机理，采用固溶时效和渗碳工艺制备了不同微观组织的Ni₃Al-Ni₃V合金，通过往复式磨损实验机测试了其室温磨损性能。实验结果发现，固溶Ni₃Al-Ni₃V合金由软的Ni₃Al相和硬的Ni₃Al + Ni₃V复合相组成；渗碳Ni₃Al-Ni₃V合金表面生成了厚度约4 μm的碳化物层和约6 μm的富Ni相过渡层，组织致密，与基体合金结合良好，具有较高硬度和弹性模量的碳化物层提高了合金的摩擦磨损性能。Ni₃Al相对环境中水汽敏感，磨损过程中易与水汽反应产生环境脆性，导致Ni₃Al-Ni₃V合金发生了磨损环境脆性，Al的临界含量为5.53 at.%。随着载荷和滑动速度的增加，固溶Ni₃Al-Ni₃V合金的磨损机制由磨粒磨损和环境脆性转变为粘着磨损，渗碳Ni₃Al-Ni₃V合金的碳化物层和富Ni相过渡层逐渐被磨掉后，也发生了环境脆性。

Abstract: To study the wear mechanism of Ni₃Al-Ni₃V alloy at room temperature, the Ni₃Al-Ni₃V alloy with different microstructure was prepared by solid solution aging and carburizing process. The wear properties at room temperature were tested by reciprocating wear testing machine. The experi-mental results show that Ni₃Al-Ni₃V alloy consists of a soft Ni₃Al phase and a hard Ni₃Al + Ni₃V composite phase. After the carburization, a carbonized layer with a thickness of about 4 μm and a Ni-rich phase transition layer of about 6 μm are formed on the surface of the Ni₃Al-Ni₃V alloy. They form a wear-resistant layer, which is densely bonded and well bonded to the matrix alloy, thereby improving the friction and wear properties of the alloy. In terms of wear mechanism, the soft Ni₃Al phase leads to the wear environment embrittlement of Ni₃Al-Ni₃V alloy and the critical content of Al is 5.53 at.%. As the load and sliding speed increase, the wear mechanism of the solid solution Ni₃Al-Ni₃V alloy changes from abrasive wear and environment embrittlement to adhesive wear. The carburized Ni₃Al-Ni₃V alloy also undergoes environmental brittleness after its carbonized layer and Ni-rich phase transition layer are gradually worn away.