科研之友
微信
新浪微博
Facebook
分享链接
摘要
The effect of a combined treatment including severe plastic deformation under the conditions of dry sliding friction and heating in air to temperatures of 300-480A degrees C (holding for 1 h) on the structure and wear resistance of the surface layer of the Ti49.4Ni50.6 alloy has been investigated. It has been shown that this frictional treatment results in an amorphous-nanocrystalline structure in the surface layer (of thickness to 10 mu m) of the Ti49.4Ni50.6 alloy. Heating to 300A degrees C brings about the complete crystallization of the amorphous phase; as a result, the structure of the deformed surface layer of the alloy becomes single-phase, consisting of nanocrystals of the B2 phase. At 400A degrees C, in this deformed surface layer there arises a nanocrystalline oxide (TiO2) phase whose amount reaches tens of volume percent. The sizes of crystals of the B2 phase and oxide TiO2 are in the range of 1-50 nm. The arising two-phase (B2 + TiO2) nanocrystalline structure is located just below the oxide TiO2 film, which is less than 1 mu m thick. With an increase in the heating temperature to 480A degrees C, the deformed surface layer under consideration retains the nanocrystalline two-phase (B2 + TiO2) structure, but an increase in the amount of the oxide phase and a decrease in the microhardness of this structure are observed. In some cases (heating at temperatures of 430 and 450A degrees C), the presence of the two-phase (B2 + TiO2) nanocrystalline surface layer leads to a noticeable (to similar to 25%) enhancement in the adhesive wear resistance of the Ti49.4Ni50.6 alloy upon sliding friction in pair with steel 40Kh13.
- 出版日期2012-6
