MA-SPS制备超细晶Ti-8Mo-3Fe合金的摩擦磨损性能

以机械合金化+放电等离子烧结(MA-SPS)制备的超细晶Ti-8Mo-3Fe合金为研究对象,研究了合金在模拟体液(SBF)中的摩擦磨损性能,并与放电等离子烧结制备的微米尺寸晶粒的Ti-8Mo-3Fe合金、铸造纯Ti及Ti-6Al-4V(TC4)合金进行了对比.结果表明:采用MA-SPS工艺可制备出高致密度、组织均匀的超细晶Ti-8Mo-3Fe合金,合金由β相及少量α相组成,平均晶粒尺寸为1.5μm,显微硬度为448 HV;在相同摩擦磨损条件下,超细晶Ti-8Mo-3Fe合金的摩损程度明显低于微米晶粒Ti-8Mo-3Fe和铸态的纯Ti及TC4合金,具有最低的磨损体积和较稳定的摩擦系数.超细晶Ti-8Mo-3Fe合金的磨损机制为磨粒磨损,而微米晶粒Ti-8Mo-3Fe和铸态纯Ti及TC4合金的磨损机制为磨粒磨损和黏着磨损并存的混合磨损.

Friction and wear properties of ultrafine grain Ti-8 Mo-3 Fe alloys fabricated by MA-SPS

The friction and wear properties of ultrafine grain Ti-8Mo-3Fe alloy fabricated by mechanical alloying (MA) and sub-sequent spark plasma sintering ( SPS) were investigated in SBF simulated body fluid. It was compared with those of as-SPSed micron size grain Ti-8Mo-3Fe alloy and as-casted Ti and TC4 alloy. The results show that ultrafine grain Ti-8Mo-3Fe alloy with high density and uniform microstructure can be fabricated by MA- SPS, and the alloy mainly consists of β-Ti phase and a small amount of α-Ti phase. The average grain size is 1. 5μm, and the microhardness is 448 HV. In the same wear condition, the wear degree of ultrafine grain Ti-8Mo-3Fe alloy is significantly lower than those of micro-crystalline Ti-8Mo-3Fe, as-casted Ti, and TC4 alloy, so it has the lowest wear volume and stable friction coefficient. Ultrafine grain Ti-8Mo-3Fe alloy is mainly characterized by abrasive wear, but micro-crystalline Ti-8Mo-3Fe, as-casted Ti and TC4 alloy are characterized by abrasive and adhesion wear.