Hardness and microstructure of Ti-15Mo-5Zr-3Al alloy for dental casting

Abstract Objective . The hardness and microstructures of Ti-15Mo-5Zr-3Al alloy castings were investigated for application to dental cast prostheses. Materials and methods. Cast specimens of Ti-15Mo-5Zr-3Al alloy, Ti-6Al-7Nb alloy and CP Ti were prepared using a centrifugal-type casting machine and a magnesia-based investment material. The hardness of the cross-sections of the cast specimens were measured. The microstructure of the castings was observed using an optical microscope and was then analyzed by X-ray diffractometry. Results and conclusions. The hardness of Ti-15Mo-5Zr-3Al alloy at the inner part of the castings was 361 Hv, while the hardnesses of Ti-6Al-7Nb alloy and CP Ti were 384 and 269 Hv, respectively. The thickness of the surface hardened layer for Ti-15Mo-5Zr-3Al alloy was thinner than those for Ti-6Al-7Nb alloy and CP Ti. The microstructure of the Ti-15Mo-5Zr-3Al alloy casting was confirmed to be β phase.