Pengaruh Variasi Suhu Proses Artificial Aging 100⁰C 150⁰C 250⁰C Terhadap Kekerasan Dan Struktur Mikro Pada Aluminium Paduan (Al-Cu)

Abstract Aluminum type material has good mechanical properties, these characteristics include resistance to corrosion, light weight, and high strength. However, these properties can still be improved by several methods, one of the methods used is aging or commonly called age hardening. Age hardening is one method that can be used to improve the mechanical properties of aluminum alloy in the form of hardness or strength. This study aims to determine changes in mechanical and physical properties of Al-Cu material before and after the age hardening process at 100⁰C, 150⁰C, and 250⁰C temperature variations that are held for 1 hour, by testing the hardness with rockwell method and observing microstructure. The results of the microstructure, show that the greater temperature will be more distantly atomic grains. This is suitable with the results of the hardness testing which decreases with each increase in temperature, with the results of the average hardness at 100 ° C, 150 ° C, 250 ° C, respectively 75.63 HRB, 68.87 HRB, 58.17 HRB. But in the testing of hardness between raw material, after quench material, and after aging material, the value of hardness decreased by 35% from the average hardness of raw material of 77.27 HRB to 50.17 HRB when the material was rapidly cooled, however the material have an increase the hardness by 35% from 50.17 HRB to 67.56 HRB after the material went through an aging process. Keywords: "age hardening, aging, quenching, Al-Cu microstructure