镍钛记忆合金自补偿磨粒磨损性能研究

研究了高临界温度镍钛记忆合金一维自补偿磨粒磨损特性.结果表明,在一定温度下,镍钛记忆合金在摩擦过程中具有形状恢复能力,从而产生一维磨损自补偿作用.超弹状态镍钛记忆合金具有热弹性马氏体相变、高阻尼、应力感生马氏体、超弹性、高应变硬化指数和时效弥散析出强化等特性,这使得硬度较低的镍钛合金的耐磨性能远优于硬度较高的淬火45#钢.利用超弹状态镍钛记忆合金的磨损自补偿作用可望开发出新型抗磨形状记忆合金产品.

Study of Self-Healing Abrasive Wear Behavior of Super-Elastic Ni-Ti Shape-Memory Alloy

The self-healing abrasion behavior of super-elastic nitinol was comparatively investigated using quenched AISI-1045 steel sample as a control. The worn surface morphologies of the steel and the Ni-Ti alloy were observed on a scanning electron microscope, the temperature on the sliding surfaces was measured with a thermocouple, and the factors affecting the abrasion behavior of the alloy were discussed. It was found that the shape memory effect of the nitinol contributed to increase its abrasion resistance which was much superior to that of the AISI-1045 steel. Thus the abrasion resistance of the shape-memory alloy was not mainly determined by its lower hardness but by its excellent shape-recovering ability. The differences in the morphologies of the worn surfaces of the steel and the shape-memory alloy conformed to their different abrasion resistance as well. It was thus suggested the shape-memory alloy of super-elasticity could be used to develop the frictional devices subject to short-journey sliding, such as clutch and braking disc.