X-선 회절을 통한 적층제조 A356.2 알루미늄 합금의 잔류응력 분석

• Published in: 대한금속·재료학회지, 61(7) Vol. 61; no. 7; pp. 534 - 544
• Main Authors: 박상철, Sangcheol Park, 김인영, Inyeong Kim, 김영일, Young Il Kim, 김대겸, Dae-kyeom Kim, 오승주, Soong Ju Oh, 이기안, Kee-ahn Lee, 이빈, Bin Lee
• Format: Journal Article
• Language: Korean
• Published: 대한금속재료학회 05.07.2023; 대한금속·재료학회
• Subjects: additive manufacturing; aluminum; powder bed fusion; residual stress; XRD; 재료공학
• ISSN: 1738-8228; 2288-8241

The physical properties of metal-based structural materials, such as hardness, strength and toughness, are directly or indirectly affected by residual stress inside or on the surface of the given part. Repeated rapid heating and cooling during the additive manufacturing process causes thermal gradients and expansion and contraction in the material, which causes residual stress. Tensile residual stresses are known to exist on the surface of additive manufactured products and should be kept to a minimum as they affect the mechanical properties and lead to product deformation and product failure. Therefore, it is important to evaluate the residual stress after making the product and to control it under the desired conditions. There are limitations to using the destructive method commonly used for residual stress evaluation with additive manufacturing products, due to difficulties in repeated measurements, product size, and cost issues. Therefore, it is necessary to apply a non-destructive evaluation method and verify the validity of the method. In this study, A356.2 aluminum alloy powders were used for additive manufacturing using the powder bed fusion process, and the surface residual stress generated during the process was measured. X-ray diffraction (XRD) methods were used to observe the surface residual stress. After XRD measurement, analyses were performed using the Williamson- Hall plot, sin 2 ψ, and cosα methods. The residual stress measurement results of samples manufactured through the LPBF process and the characteristics and limitations of each method were discussed. (Received 6 February, 2023; Accepted 3 April, 2023)