Quality Assurance in metal additive manufacturing from a design perspective

Abstract

Quality by design (QbD) is a strategic approach that ensures that quality becomes a built-in feature of processes in production. It presents a systematic approach to process development and quality management. It begins with defining quality objectives and emphasises process understanding and control based on scientific analysis and quality risk management. This study proposes and demonstrates QbD principles to address quality inconsistencies and reliability challenges in the LPBF process, especially for batch production. Our findings indicate that despite recent technological advancements in laser powder bed fusion (LPBF), it still faces challenges with process control and varying quality outcomes in batch productions. Due to these challenges, quality strategies become essential. The QbD principles and Failure Mode and Effect Analysis (FMEA) were applied to identify potential quality failures in LPBF, focusing on the screwdriver bit as a case study. Hardness appeared as one of the critical to quality elements. Low hardness was identified as a critical failure mode that could lead to substrate damage during the application of the screwdriver bits. Powder quality analysis before production and development of parameter selection tool proposed as countermeasures to address these potential defects. Furthermore, this study emphasises the significance of QbD in establishing process control and ensuring consistent quality in batch production in the technology.