Defects in Metal Additive Manufacturing: Formation, Process Parameters, Postprocessing, Challenges, Economic Aspects,...

Area of Science:

• Materials Science
• Manufacturing Engineering

Background:

• Metal additive manufacturing (AM) offers design freedom and efficiency across industries like aerospace and healthcare.
• Internal stresses and microstructural defects significantly impact AM part integrity, quality, and lifespan.
• Defect identification and prediction are crucial for producing high-density, defect-free components.

Purpose of the Study:

• To provide detailed insights into common defects in powder bed fusion (PBF) and wire arc additive manufacturing (WAAM).
• To explore defect mitigation techniques and associated challenges in metal AM.
• To critically analyze methods, alloys, process parameter optimization, and postprocessing for defect reduction.

Main Methods:

• Review of common defects, including porosity, in PBF and WAAM processes.
• Analysis of factors contributing to defect formation, such as powder characteristics, preheating, and build environment.
• Examination of various mitigation techniques and postprocessing strategies.

Main Results:

• Identified key factors influencing porosity, including powder properties, thermal management, and process parameters.
• Detailed common defects and their origins in both PBF and WAAM.
• Highlighted the importance of process parameter optimization and postprocessing for defect control.

Conclusions:

• Effective defect management in metal AM requires a comprehensive understanding of formation mechanisms.
• Optimizing process parameters, material selection, and postprocessing are essential for enhancing part quality and reliability.
• Continued research into defect mitigation is vital for advancing metal additive manufacturing applications.