EFFECT OF HEAT TREATMENT ON MICROSTRUCTURE AND MECHANICAL PROPERTIES OF TI-CU-MG ALLOY FABRICATED USING SPARK PLASMA SINTERING

• Main Author: Nishura Gurusinga, Josevan
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/76496
• Institution: Institut Teknologi Bandung

One of the biomaterials that can be used as orthopedic implants is the Ti-Cu-Mg alloy. The Ti-Cu-Mg alloy is expected to be able to combine the advantages of alloying elements Cu and Mg to obtain good mechanical properties, biocompatibility, and corrosion resistance, as well as anti-bacterial properties, low modulus of elasticity, and magnesium can dissolve to form calcium phosphate. The spark plasma sintering (SPS) method was chosen to prepare the Ti-Cu-Mg alloy due to the method's limitations for forming the alloy. The Ti-Cu-Mg alloy is still relatively new, so studies related to heat treatment of Ti-Cu-Mg alloy have never been carried out, so an attempt is made to study the effect of heat treatment on the microstructure and mechanical properties of the Ti-Cu-Mg alloy with three different compositions, Ti-5Cu-1Mg, Ti-5Cu-3Mg, and Ti-5Cu-5Mg. The heat treatment begins with a solution treatment which is carried out at 900°C for 2 hours, followed by water quenching. The aging heat treatment carried out afterward was divided into 2, one-step aging, at a temperature of 400°C with a holding time of 4, 8, 24 hours, and two-step aging, at a temperature of 475°C with a holding time of 8 hours. The results of each variation of heat treatment will be analyzed for its microstructure with an optical microscope (OM) and scanning electron microscope – energy dispersive x-ray spectroscopy (SEM-EDS). The mechanical property was tested with a microhardness test, and the hardness value of the alloy could be obtained. Heat treatment of the Ti-Cu-Mg alloy affects the microstructure and mechanical properties of the alloy. One-step aging heat treatment showed that the microstructure of Ti2Cu precipitates, and the amount increased with increasing holding time. Heat treatment of two-step aging generally makes nucleation occur thoroughly and optimizes precipitate growth, but in Ti-5Cu-3Mg alloy, which is given one-step aging heat treatment for 24 hours followed by two-step aging, overaging occurs. In general, the distributed magnesium is finer the longer the holding time of one-step aging and when two-step aging is carried out, the distributed magnesium has a different tendency for each alloy composition. The hardness of Ti-5Cu-1Mg, Ti-5Cu-3Mg, and Ti-5Cu-5Mg after being heat treated sequentially can reach 677.2 HV, 654.8 HV, and 531 HV.