多次冲击载荷下TiNiNb合金的反常磨损行为

Abnormal wear behavior of TiNiNb alloy under multiple impact loads

在往复冲击载荷下对TiNiNb合金的冲击磨损性能进行研究。结果表明:当单位面积冲击能量为1.61J/cm2时,TiNiNb合金表现出通常的耐磨行为,磨损率始终维持稳定;但当单位面积冲击能量上升到2.42 J/cm2且冲击进行到30万次后,磨损率曲线发生转折,转折后的磨损率仅为1.61 J/cm2冲击时的1/2.1。经X射线衍射分析和扫描电镜观察发现,磨损率下降的主要原因是高能冲击30万次后,表层组织中出现大量的非晶,导致通常的磨损机制在很大程度上受到抑制,使磨损率急剧下降,并因此使得高能量冲击下的磨损量最终也低于低能量冲击下的磨损量。

The impact wear test to TiNiNb alloy was carried out, and an abnormal wear phenomenon was discovered. The TiNiNb alloy exhibits common wear behavior when the energy of per unit area is 1.6 J/cm^2 , and the wear rate keeps invariable all the time. When the energy of per unit area rises to 2.4 J/cm^2 and the impacting times reach to 30 × 10^4 , the wear rate curve shows a noticeable decrease, and the decreased wear rate is only 1/2.1 of that under 1.6 J/cm^2. With the help of X-ray diffractrometry and transmission electron microscopy, it is found that after impacting with the energy of 2. 4 J/cm^2 , a lot of amorphous appear in the surface layer of specimen after 30 × 10^4 times, the appearance of amorphous restrains strongly the common wear process so that the wear rate and wearing capacity are all lower than those under 1.6 J/cm^2.