Effect of cooling mediums on mechanical properties and wear behaviour of binary β-type Ti-Mo alloy for bio-implant applications

^1* Pyrometallurgy Division, Mintek, Private Bag X 3015, Randburg 2125, South Africa, MukhethwaN@mintek.co.za
² Advanced Materials Division, Mintek, Private Bag X 3015, Randburg 2125, South Africa, MajeP@mintek.co.za, bonganing@mintek.co.za
³ Centre for Nanoengineering and Advanced Materials, School of Mining, Metallurgy and Chemical Engineering, University of Johannesburg, P.O. Box 17011, Doornfontein 2028, South Africa, mukheathwa@gmail.com, polubambi@uj.ac.za

^* Corresponding author: MukhethwaN@mintek.co.za, Mukheathwa@gmail.com

Abstract

Orthopaedic implants are increasingly used to correct skeletal dysfunctions by replacing or repairing damaged bone tissue with appropriate biomaterials. This study investigates the effect of cooling medium on the mechanical properties and wear behaviour of the solution heat-treated β-type Ti-Mo alloy. Samples were solution heat-treated at 900℃ and cooled in different cooling media, such as water quenching, air, and furnace cooling. The phases, morphology, and microstructural analyses were performed using X-ray diffraction (XRD), optical microscope, and electron backscatter diffraction (OM and EBSD). The mechanical and nanomechanical properties of the alloys were analysed using Vickers hardness and nanoindentation machines. The wear test analyses of the alloys were conducted using a tribometer. XRD and microstructural characterization showed the crystalline phase, and the microstructure of the alloys was affected by the cooling medium. The furnace-cooled sample yielded high micro-hardness (454 HV) due to the grain refinement attributed to the presence of α phase.