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.

Key Words::

• castability
• hardness
• microstructure
• titanium alloy
• titanium

Acknowledgements

This work was supported in part by a Grant-in-Aid for Science Research (C) 20592283 (2008) from the Japan Society for the Promotion of Science and Special Research Grants for the Development of Distinctive Education from the Promotion and Mutual Aid Corporation for Private School of Japan (2008 and 2009). This project was also supported in part by Sato Fund, Uemura Fund and Grant from Dental Research Center, Nihon University School of Dentistry.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.