Investigation of friction and wear behavior of NiAl--based alloys at room temperature
三种NiAl材料的室温摩擦磨损性能

The friction and wear properties of NiAl, NiAl--Cr(Mo)--Hf eutectic alloy and NiAl--Al2O3--TiC composite were investigated with an MRH-5A friction and wear tester. The results showed that the wear resistance of NiAl-based alloys was directional propertional to their hardness and fracture toughness and the friction coefficient ecreased with the increasing hardness. Among the above three alloys, NiAl--Al2O3--TiC composite possessed the best friction and wear properties. The wear mass loss only one-fourth to three-fourthes of that of NiAl--Cr(Mo)--Hf eutectic alloy or one-twentieth to one-tenth of that of NiAl alloy, which was attributed to the efficient transferring stress and supporting effect of reinforcing ceramic particles. The wear process of three NiAl materials is dominated by plastic deformation, and the main wear mechanism of the three NiAl--based alloys was abrasive wear. With the increase of load, the wear surfaces exhibit orderly such wear mechanisms as distinct plastic deformation, spalling and adhesion wear. The wear mechanism played an important role in the wear rate and friction coefficent.