Al 5052-H32 합금의 저항 점 용접 시 가압력 제어 방식에 따른 미세조직 및 용접특성 비교

• Published in: 대한금속·재료학회지, 60(5) Vol. 60; no. 5; pp. 350 - 359
• Main Authors: 김원호, Wonho Kim, 김재훈, Jaehun Kim, 전현욱, Hyunuk Jun, 김재원, Jaewon Kim, 이은경, Eunkyung Lee, 지창욱, Changwook Ji
• Format: Journal Article
• Language: Korean
• Published: 대한금속재료학회 01.05.2022; 대한금속·재료학회
• Subjects: aluminum alloy; defects in nugget; electrode-force control; microstructure; resistance spot welding (RSW); 재료공학
• ISSN: 1738-8228; 2288-8241
• DOI: 10.3365/KJMM.2022.60.5.350

Recently, lightweight vehicle bodies are in increasing demand to satisfy exhaust gas and environmental regulations around the world. In particular, aluminum alloys are widely used to manufacture lightweight parts, because of their excellent properties including corrosion resistance and mechanical properties. After the forming process, the welding process is important for manufacturing aluminum alloy parts. Resistance welding of aluminum alloys has several problems, due to internal weld defects such as cracks, shrinkage cavity, or porosity, which can result from the Al 2 O 3 oxide film on the surface of the aluminum alloy. This study investigated electrode-force type controls to improve the weldability of the aluminum alloy. It was found that a high electrode-force on squeeze time can collapse the Al 2 O 3 oxide film on the surface. It can reduce defects in the nugget by about 42%, by reducing heat input energy, compared to the continuous electrode-force 4 kN (reference value). Also, with high electrode-force during the hold time, defects were reduced by about 80%, by increasing the cooling rate. The weld quality has a great influence on the electrode-force type control, and internal defects in the nugget are greatly affected by the electrode-force on hold time. (Received 22 November, 2021; Accepted 10 January 2022)