Investment casting of semi-solid 6063 aluminum alloy using the GISS process

Abstract

Investment casting has long been known as a process that can produce complex parts with fine details. However, it has not been used widely for parts that need to be anodized and whose nonuniform color is affected by the type of cast aluminum. Although 6063 aluminum is widely used in color anodizing for decoration purposes, it is almost entirely wrought. Some studies have used aluminum 6063 in cast aluminum, but no investment casting studies have been reported. The objective of this work is to develop a new semi-solid investment casting process using 6063 aluminum alloys to achieve a cosmetic anodized workpiece. To study the feasibility of the gas-induced superheated slurry (GISS) investment casting process, the effects of rheocasting time, mold temperature, and vacuum assistance were investigated. The results showed that the samples produced using the GISS process had a uniform microstructure and less porosity. The uniform color after anodizing and coloring also confirmed these processes. From the results, it can be summarized that the GISS process is feasible for application in aluminum 6063 investment casting for anodizing and coloring purposes.