Effect of cryogenic-thermal cycling treatment on tribological properties of Ti-based amorphous alloy

Abstract

The wear resistance of titanium alloy is poor, the preparation of amorphous alloy coating on the surface of titanium alloy moving parts is a choice to maintain the advantages of titanium alloy and improve its wear resistance. The microstructure and tribological behaviour of Ti-based bulk amorphous alloy before and after cryogenic-thermal cycling treatment were studied by XRD diffractometer, differential scanning calorimeter, SEM, friction and wear tester. The results show that after cryogenic-thermal cycling treatment, the titanium-based bulk amorphous alloy remains completely amorphous, and the relaxation enthalpy increases by 11%. After cryogenic-thermal cycling treatment, the average hardness of Ti-based amorphous alloy decreases from 6.84 GPa to 6.59 GPa and the average elastic modulus decreases from 118.70 GPa to 103.43 GPa, but the ratio of hardness to elastic modulus increases. The wear rate of titanium-based bulk amorphous alloy after cryogenic-thermal cycling treatment is reduced by about 10% under the load of 5 N and 10 N. Compared with TC4 alloy, the wear rate is reduced by 20% under 5 N load and 50% under 10 N load, respectively.TC4 alloy shows serious adhesive wear due to its low hardness. After cryogenic-thermal cycling treatment, the wear mechanism of titanium-based amorphous alloy is changed from abrasive wear of as-cast Ti-based amorphous alloy to the complex mechanism with abrasive, adhesive and oxidation wear. With the increase of load, adhesive wear decreases and abrasive wear is dominant.Generally, cryogenic-thermal cycling treatment is an effective way to improve the tribological properties of Ti-based bulk amorphous alloy.

Keywords

• titanium
• amorphous alloy
• cryogenic-thermal cycle
• wear resistance
• nano-indentation
• tribology