Process Optimization for Improving Multiple Quality Attributes of AlSi10Mg Alloys Manufactured by Selective Laser Melting Based on Integrated Overall Quality Index

Abstract

Selective laser melting (SLM) technique is one of the most popular advanced manufacturing techniques. The SLM process parameters affect the multiple quality-attributes of the SLM-built parts. The aim of this work is to develop a new optimization methodology of the SLM process parameters for improving the multiple quality attributes of the SLM-built parts. It is a multi-objective optimization (MOO) problem. The multiple quality attributes are converted into a single overall quality index (OQI) using multi atrribute decision making (MCDM) method, and the MOO problem converted into a single objective optimization (SOO) one. The optimization result may differ according to the applied MCDM method. To address it, this work proposed a reasonable process optimization methodology for improving multiple quality attributes of the SLM-built parts using integrated OQI (I-OQI) combined with multiple OQIs obtained from multiple MADM methods. The proposed methodology was applied to optimize the process parameters such as laser power (LP), scan speed (SS) and overlap rate (OR) for improving five quality attributes such as tensile strength, hardness, relative density, volumetric energy density, and build rate of the SLM-built AlSi10Mg alloy. The optimal values of the SLM process parameters obtained from Taguchi and grid search optimization methods were LP of 320 W, SS of 900 mm/s, and OR of 0.25. The methodology could be actively applied to the SLM process optimization for not only Al alloys but also various metal/alloys.