Pengaruh Artificial Aging terhadap Struktur Mikro dan Sifat Mekanik Komposit Al-4,5Cu-0,5Mg-2SiC dengan Proses Metalurgi Serbuk

Abstract

Aluminum in the form of an alloy is a type of aluminum that is used quite a lot today. All types of aluminum alloys contain two or more chemical elements that can affect the mechanical properties of the alloy. In this study, the Al-Cu-Mg-SiC alloy was subjected to heat treatment in the form of artificial aging to determine the effect on the mechanical properties of hardness, compression, density, microstructure, and macrostructure of various artificial aging time variations in powder metallurgy processes. This research with variations of holding time (2, 4, and 6 hours). Specimens were made by mixing aluminum, copper, magnesium, and silicon carbide powder with respective compositions of 93%, 4.5%, 0.5%, and 2% (wt) SiC using a horizontal ball milling machine for 1 hour. The alloy mixture was put into the mold and compacted with a pressure of 240 MPa for 15 minutes. The compacted specimens (green compact) were then sintered at 500 °C for 1 hour. The compressive strength, Vickers hardness, density, and macrostructure were tested and the microstructure was observed using an optical microscope. In the test, it was found that there was an increase in the values of density, hardness (Vickers), and compressive strength along with the increasing artificial aging time given. The results of the highest density, hardness, and compressive strength values were at 6 hours of artificial aging with a value of 1.6741 gr/cm3, a hardness value of 48.2 VHN, and a maximum compressive strength value of 119.92 MPa. The microstructural test shows that the grain boundaries are tighter and the size of the Al grain diameter is getting bigger.