STUDY OF HEAT TREATMENT EFFECT OF TI-CU ALLOYS MADE BY SPARK PLASMA SINTERING METHOD ON MICROSTRUCTURE AND MECHANICAL PROPERTIES

• Main Author: Mahendra, Rio
• Format: Final Project
• Language: Indonesia
• Subjects: Metalurgi
• Online Access: https://digilib.itb.ac.id/gdl/view/69868
• Institution: Institut Teknologi Bandung

Bone implants are a device to treat bone disorders by replacing or supporting the process of repairing damaged bones. The need for bone implants will increase every year. One of the alloys used for alloy in bone implants is titanium, which is an alloy that has an excellent combination of strength, Young`s modulus, and biocompatibility. The addition of copper elements to titanium can increase the antibacterial properties of the alloy. Spark plasma sintering (SPS) method is a powder metallurgy technology used to make high density solids from its constituent powders. Heat treatment of the alloy can change the microstructure and mechanical properties which can affect the performance of the alloy as an implant. This study was conducted by heat treatment of titanium copper alloy made by SPS. The variables in this experiment were the composition of copper in the SPS alloy, which were 1, 3, and 5 wt%, and the cooling process after heat treatment, which were water cooling, air cooling, and furnace cooling, and the alloy without heat treatment as a comparison. The heat treatment performed on the alloy is heating the alloy to a temperature of 900°C and holding it for 2 hours. Microstructural observations were done using an optical microscope and hardness testing using a Vickers hardness test. The results of the analysis of microstructure, grain size, and hardness properties were compared for each variation. The results showed that in general, the initial conditions of the copper-titanium alloy produced by SPS remained dominant in the hardness properties of the alloy after heat treatment. The results of the microstructure analysis showed that the grain size of the titanium copper alloy grew after heat treatment with the highest average grain size in the Ti-1%Cu alloy with furnace cooling. The observed phase transformation is the diffusion of copper into the titanium matrix after heat treatment so that the Ti2Cu phase in the SPS alloy transforms to ?-Ti phase and martensitic structure consisting ?’ martensite and the retained ? in water quenching and water cooling and also ?-Ti phase and lamellar structure between Ti2Cu and ?-Ti in furnace cooling. The heat treatment of the Ti-1%Cu and Ti- 3%Cu alloys resulted in a non-significant decrease in the hardness value, while in the Ti-5%Cu alloy there was a significant decrease in the hardness value. The relationship between grain size and hardness value is that there is a tendency for the hardness value to decrease as grain size increases for each copper grade, indicating that grain size is more dominant in influencing the hardness value.