Author/Authors :
Hu، نويسنده , , T. and Wen، نويسنده , , C.S and Sun، نويسنده , , G.Y. and Wu، نويسنده , , S.L. and Chu، نويسنده , , C.L. and Wu، نويسنده , , Z.W. and Li، نويسنده , , G.Y. and Lu، نويسنده , , J. and Yeung، نويسنده , , K.W.K. and Chu، نويسنده , , Paul K.، نويسنده ,
Abstract :
An ultrafine grain layer consisting of nanocrystallites as well as submicrometer grains is produced on NiTi shape memory alloy by surface mechanical attrition treatment (SMAT) and the effects of the ultrafine grain layer on the tribological properties are investigated under dry sliding conditions. Compared to the coarse grain (CG) NiTi, the SMAT NiTi has smaller friction coefficients and improved wear resistance at applied loads from 5 to 15 N due to the grain refinement effect. Examination of the worn surfaces indicates that materials delamination and particles co-exist on both the CG and SMAT NiTi samples. Our results indicate that delamination is the main wear mechanism on CG NiTi whereas abrasive particles dominate the wear process on SMAT NiTi.
Keywords :
Nickel titanium shape memory alloy (NiTi SMA) , Surface mechanical attrition treatment (SMAT) , Grain refinement , Wear resistance , ultrafine grain
