THE EFFECT OF PRECIPITATION HARDENING ON WEAR RESISTANCE OF AL-SI-MG ALLOY

• Main Author: Fajar Aliya, Fayza
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/83311
• Institution: Institut Teknologi Bandung

Tribology is a branch of science that discusses friction, wear, and lubrication of interacting surfaces. High wear resistance is required for several machine components, one of which is the engine cylinder block that constantly interacts with the piston. One suitable material for use as an engine cylinder block is the Al-Si alloy, which has low density and good castability. However, the alloy has low wear resistance. By adding the alloying element Mg, the hardness of the Al-Si-Mg alloy can be increased through thermal treatment. The aim of this study is to determine the effect of different aging temperatures during the precipitation strengthening process on the hardness, microstructure, and wear resistance of the Al-Si-Mg alloy. The wear test in this study was conducted using a pin-on-disk apparatus with three mechanisms: dry sliding wear, two-body abrasive wear, and three-body abrasive wear to observe the tribological characteristics of the Al-Si-Mg alloy. Further testing, including OES (Optical Emission Spectroscopy), metallography, hardness testing, visual observation, and density testing, was carried out to assist in the analysis and conclusion preparation. The test results showed that material strengthening through the precipitation strengthening process successfully increased the hardness of the alloy and altered the microstructure. Additionally, wear resistance also increased up to an aging temperature of 175°C, as indicated by a decrease in mass loss. However, in the sample aged at 200°C, wear resistance decreased. This occurred due to the presence of defects in the form of porosity in the sample aged at 200°C.