PENGARUH VARIASI UNSUR AL DAN NB TERHADAP DESAIN PADUAN TI-AL-NB DENGAN SIMULASI MOLECULAR DYNAMIC UNTUK APLIKASI BIOMEDIS

• Main Author: Rosyid Ridho, Muhammad
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/69144
• Institution: Institut Teknologi Bandung

Titanium and its alloys are often used for biomaterials because it has good combination of mechanical properties and biocompatibility, and also economical in terms of price. Ti-6Al-4V extra low interstity (ELI) is often used for biomaterials, it has good strength and is widely used, but vanadium has a relatively high level of toxicity, so vanadium will be replaced by niobium that has a lower level of toxicity. Ti-Al-Nb that has been standardized for implant raw materials is Ti-6Al-7Nb, so in this study it will be seen how the influence of Al and Nb with the variation around the composition of Ti-6Al-7Nb. Conventional metal alloy designs need long time and big cost, so that by conducting molecular dynamic simulations, the predictions obtained from mechanical properties are faster and cheaper as well as with a large number of atom with variant temperatures. Molecular dynamic simulations were carried out using the LAMMPS with HCP alloy structure and composition variations of 4-8 wt.% Al and 3, 5, 7, 9, 11 wt.% Nb with random atomic distribution and at a temperature of 300 K, number of atom is 2000 with directions x [2-1-10], y [-12-10], z [0001]. The simulation begins with the optimization of the structure so that the lattice parameter values a and c are in equilibrium, then proceed with a uniaxial tensile test simulation, and a stacking fault energy (SFE) calculation. Based on result, the addition of Al to Ti metal and Ti-Nb alloys will decrease the lattice parameter a and increase the lattice parameter c. The addition of Nb to Ti will increase the lattice parameter a and decrease the lattice parameter c, while the effect of adding Nb to Ti-Al on the lattice parameter is stagnant. The effect of adding Al and Nb content to Ti metal and Ti-Al-Nb alloy will increase ultimate tensile strength (UTS) with the effect of addition of Nb to add strength is more than the addition of Al and the addition of Al to Ti-Al-Nb is more strengthening than the addition of Nb. The addition of Al and Nb to Ti metal and Ti-Al-Nb alloy reduces the stacking fault energy (SFE) with the effect of adding Nb to Ti is lowering more SFE than adding Al to Ti. As for the addition of Al to Ti-Al-Nb, SFE decreases greater than the addition of Nb.