材料期刊网

In this work, the dry sliding friction and wear properties of Ti(3)AlC(2) and Ti(3)AlC(2)/Al(2)O(3) composites against AIS152100 steel ball were investigated using a reciprocating ball on flat configuration under different normal loads. The results indicated that the friction/wear processes of both Ti(3)AlC(2) and the composites against AIS152100 steel experienced two different stages with an abrupt transition between them under all test conditions. The first stage was characterized by low coefficient of friction (It) and neglectable wear rate. While the second stage was of much higher wear rate and It. When the transition occurred, M increased dramatically accompanied with formation of a mass of debris. In Ti(3)AlC(2), the main wear mechanisms during the first stage involved surface materials transfer and oxidation accompanied with subsurface damages by grains kinking, delamination as well as transgranular and intergranular cracks. Accumulating of such contact damages under repeated sliding contact finally leaded to surface and subsurface microfracture of Ti(3)AlC(2). Then microfracture controlled severe wear started. Incorporation of Al(2)O(3) in Ti(3)AlC(2) not only improved wear resistance of Ti(3)AlC(2) but also extended the first mild friction/wear stage, because Al(2)O(3) particles borne load and restrained large-scale deformation and microfracture of Ti(3)AlC(2). (C) 2008 Elsevier B.V. All rights reserved.