Microstructure evolution and mechanical property of powder metallurgy Ti6Al4V alloy with high oxygen concentrations

ABSTRACT

High oxygen Ti6Al4V alloys are fabricated by vacuum sintering and hot rolling using hydrogenation-dehydrogenation Ti6Al4V powder and ZrO₂ powder as raw materials. The complete dissolution of oxygen and zirconium atoms results in an increase in lattice constant and strength. As-rolled Ti64-ZrO₂ sample exhibits a bimodal structure with a fine acicular α phase of around 1 μm. Ti64-0.75 ZrO₂ alloy with equivalent oxygen content close to 0.6 wt.-% presents a good combination of the high tensile strength (1180.2 MPa) and sufficient elongation (7.3%). Therefore, the critical oxygen content for the ductile-to-brittle transition of powder metallurgy Ti6Al4V alloy can be improved by suitable preparation methods. The formation of a fine β transformation structure may be one of the reasons for maintaining sufficient ductility.

KEYWORDS:

• Powder metallurgy
• titanium alloy
• mechanical property
• high oxygen
• zirconium dioxide

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the National Natural Science Foundation of China [grant number 52004027], [grant number U21A200305], and [grant number 51925401], Innovation Group Project of Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Guangdong, China [grant number 311021013], and the Scientific and Technological Innovation Foundation of Foshan, USTB, China [grant number BK21BE001], and [grant number BK22BE007].