Of Ti6a14v Thermal Oxidation Process And The Performance Of The Internal Friction Of The Alloy

Titanium alloys posses excellent a desirable combination of attractive properties, and then these attractive properties of titanium alloys makes them suitable for wide range of applications, range from aerospace through defence, chemical, petrochemical, marine and offshore. On the other hand, the use of titanium alloys has been restricted by poor tribological properties and low damping capability. In order to improve the wear-resistance and the damping capability of titanium alloys, the thermal oxidation process and hot treatment have been investigated.By the use of Optical Microscope, XRD, SEM, TEM, Microhardness Tester, Pin-on-Disc Tribometer and Multifunctional Ultrason Icmeter, the modification of the thermal oxidation process on the surface of T16A14V alloy was analyzed, the influence of the thermal oxidation process on wear-resistance of the surface of Ti6A14V alloy was tested, the influence of hot treatment on microstructure and phase transformation of Ti6A14V alloy was studied, and the internal friction properties of samples under different heat treatment were compared. The main conclusions were obtained as follows:(1) Thermal oxidation (TO) process mean that Ti6A14V alloy has been oxidized for different times at 850'C under the air condition, then followed by vacuum diffusion at 850 "C for 12h. The diffusion treatment in vacuum is the essence of the thermal oxidation process.(2) TO can modify the properties of Ti6A14V surface. A strengthened layer penetrated by oxygen and special oxide have been obtained. They improve the wear-resistance of Ti6A14V alloy.(3) Under low stress and intermediate stress conditions, mass loss of TO-treated specimens were low. However, when a higher load was applied, mass loss of all specimens were almost the same. So TO can not be applied to high load.(4) Hot treatment can significantly influence the phase transformation and microstructure of Ti6A14V alloy. The volume fraction and composites of the second phase of specimens were obviously different. Aging treatment can significantly improve the hardness of the quenched specimens, but decrease the damping capability.(5) The damping capability of the quenched specimen at 900 X? is the highest, about 1.3 x 10'3.