Optimization of the Heat Treatment Parameters for Al-Mg-Si Wrought Alloys Using Taguchi Approach

Abstract

This paper describes a heat treatment process using Taguchi’s robust design method to determine the optimal heat treatment conditions for Al-Mg-Si wrought alloys, which is an alloy used in automotive body panels. Important factors influencing the optimization criteria include solution temperature, solution time, pre-aging temperature, and pre-aging time. The optimal heat-treatment conditions for both microhardness and paint-bake response of the Al-Mg-Si wrought alloys are a solution temperature of 550°C, solution time of 30 min, pre-aging temperature of 90°C, and pre-aging time of 60 min. The optimal conditions for tensile strength are a solution temperature of 530°C, solution time of 60 min, pre-aging temperature of 90°C, and pre-aging time of 30 min. Experimental results indicate that solution temperature is the most significant factor for both microhardness and alloy elongation, solution time is the important factor for yield-strength, and pre-aging temperature is the most significant factor for paint-bake response and ultimate tensile strength.