Tribological performance of additively manufactured CoCr and Ti64 Alloys

• Main Author: Goh, Clinton Peng Hwee
• Other Authors: Liu Erjia
• Format: Final Year Project
• Language: English
• Published: 2018
• Subjects: DRNTU::Engineering
• Online Access: http://hdl.handle.net/10356/74707
• Institution: Nanyang Technological University

Biomedical implants are medical apparatus manufactured to replace or enhance damaged biological structures. One such application is hip implantation. Hip joints/implants which made up of a ball and a socket when in contact for a period of time, metal debris formed and are detrimental to a human’s body. Two of the properties that mainly contribute to the formation of wear debris are corrosion and wear of the materials used. Biomaterials that are widely used are titanium and cobalt chromium. As Additive Manufacturing (AM) is increasingly being applied and slowly replacing conventional manufacturing, complicated designs unable to achieve through traditional manufacturing can now be easily manufactured with AM. Hence, by incorporating the use of AM to produce biomaterials, studies of wear and corrosion were carried out in comparison with biomaterials produced by conventional casting methods. This report aims to study the tribological behaviours of additively manufactured CoCr and Ti64 alloys when submerged in simulated bodily fluids undergoing wear. There were 3 different types of samples which consisted of As-cast and EBM built 10mm and 1mm samples used for each type of biomaterial. The use of triboelectrochemical method such as open circuit potential measurement was applied to access the microstructural differences between different sample thickness and how the coefficient of friction relates to the corrosion and wear rate differed in the simulated bodily fluid. Furthermore, Vickers hardness test were carried out to determine the hardness of samples and compared with wear rate, microstructure and COF to determine the relation.