Improvement of Ti6Al4V Sintering Process using Arc Plasma Sintering (APS) on Formation of TiO2 Surface Layer
Sugeng Supriadi (a*), Fanny Arviani (b), Dhyah Annur (b) , Arbi Dimyati (c), Bambang Suharno (b)
a) Department of Mechanical Engineering, Faculty of Engineering, Universitas Indonesia, Depok 16424, Indonesia
*sugeng[at]eng.ui.ac.id
b) Department of Metallurgy and Materials Engineering, Faculty of Engineering, Universitas Indonesia, Depok 16424, Indonesia
c) Center for Science and Technology for Advanced Materials, BATAN-Indonesia
Abstract
In this study, fabrication process of Ti6Al4V implant material was developed using powder metallurgy. However, due to the high reactivity of titanium with oxygen at high temperature during sintering, TiO2 layer, which is excellent to corrosion resistance loses its protective properties and allows oxygen to diffuse into the bulk of material. This phenomenon is commonly undesirable because it can be detrimental which decreases the quality of material bonds and mechanical properties that causes brittle material. The Arc Plasma Sintering (APS) method was used to protect the material from the formation of an oxide layer (TiO2) on the Ti6Al4V surface and protects from oxygen diffusion. Sintering process was investigated using a new technology of Arc Plasma Sintering (APS). This sintering technology is carried out using both currents and plasma as a heat source which is capable of performing the sintering process with a very short time in just minutes, and low energy consumption. Sintering was performed on 50 A currents with variations in sintering time for 4 minutes, 8 minutes and 12 minutes. The results of the Arc Plasma Sintering (APS) process were compared to sintering using argon atmosphere at a temperature of 1300oC for 2 hours, 3 hours and 4 hours. The material characterization was performed using SEM-EDS and XRD. The density and hardness testing were measured between two methods of Arc Plasma Sintering (APS) and argon sintering. The results of this study indicate that with the Arc Plasma Sintering (APS) method, the material has better density and hardness with a relative density value of 98.40%, hardness value of 375 HV, and the thickness of the TiO2 surface layer continues to decrease from 16.4 µm to 12 µm without any diffusion of oxygen into the material when compared to argon sintering.
Keywords: Ti6Al4V, High Temperature, Arc Plasma Sintering, Oxidation, TiO2 layer
Topic: Theoretical and Analysis in Materials