Diffusion bonding of Ti-6Al-4V titanium alloy powder and solid by hot isostatic pressing
(School of Mechanical Engineering and Automation, Beihang University, Beijing 100191, China)
Abstract: The Ti-6Al-4V (TC4) alloy powder and forged solid were diffusion bonded by hot isostatic pressing (HIP) to fabricate a powder-solid part. The microstructure of the powder-solid part was observed by scanning electron microscope (SEM). The microhardness and tensile tests were conducted to investigate the mechanical properties. The results showed that the powder compact was near-fully dense, and the powder/solid interface was tight and complete. The microhardness of the interface was higher than that of the powder compact and solid. The fractures of all powder-solid tensile specimens were on the solid side rather than at the interface, which indicated that a good interfacial strength was obtained. The tensile strength and elongation of the powder compact were higher than those of the solid. It is concluded that the HIP process can successfully fabricate high-quality Ti-6Al-4V powder-solid parts, which provides a novel near net shape technology for titanium alloys.
Key words: Ti-6Al-4V alloy; powder/solid interface; hot isostatic pressing; diffusion bonding; microstructure; mechanical properties