Al-Zn-Mg-Cu계 알루미늄 합금의 열간 균열 특성에 미치는 합금조성의 영향

• Published in: 대한금속·재료학회지, 50(9) Vol. 50; no. 9; pp. 669 - 675
• Main Authors: 김지훈, Jee Hun Kim, 조재섭, Jae Sub Jo, 심우정, Woo Jeong Sim, 임항준, Hang Joon Im
• Format: Journal Article
• Language: Korean
• Published: 대한금속재료학회 20.09.2012; 대한금속·재료학회
• Subjects: aluminum alloy; casting; hot tearing; solidification; 재료공학
• ISSN: 1738-8228; 2288-8241
• DOI: 10.3365/KJMM.2012.50.9.669

Hot tearing was the most significant casting defect when the castability evaluation of the Al- Zn-Mg-Cu alloy system was conducted. It was related to the solidification range of the alloy. Therefore, the hot tear susceptibility of the AA7075 alloy, whose solidification range is the widest, was evaluated. The hot tear susceptibility was evaluated by using a mold for a hot tearing test designed to create the condition for the occurrence of hot tear in 8 steps. According to the tearing location and shape, a hot tear susceptibility index (HTS) score was measured. The solidification range of each alloy and hot tear susceptibility was compared and thereafter the microstructure of a near tear defect was observed. As a result, the HTS of the AA7075 alloy was found to be 67. Also, the HTS in relation to a change in Zn, Mg, Cu composition showed a difference of about 6-11% compared to the AA7075 alloy.