생체용 마그네슘 합금은 전연성 부족과 열에 의한 팽창률 변화가 심하여 2mm 이하의 판재를 만드는 것이 매우 어려움 문제이다. 이를 해결하기 위해 압연 방식, 세이퍼 방식, 밀링 방식 등의 다양한 방법이 존재할 수 있다. 압연 방식을 적용하여 실험을 진행하였으나 Mg 합금은 전연성, 취성의 문제로 인해 파괴되는 현상이 발생하였다. 그리고 세이퍼 방식은 가공시 충격이 발생하는 단속절삭이기 때문에 표면에 자국이 남게 되고 시험편이 휘어지는 현상이 발생하는 문제가 발생하였다. 최종적으로 밀링 방식으로 전환하여 가공실험을 수행해 본 결과 매우 만족할 만한 결과값을 얻게 되었고, 이 결과는 절삭조건을 절삭회전수 1000rpm, 이송속도 127mm/rev, 절삭깊이 0.5mm로 엔드밀 사용하여 가공하였을 때 Ra = 0.44㎛의 표면거칠기값을 얻게 되었다. 본 논문에서는 생체 마그네슘 합금재료로 미소판재를 가공하였을 때 매우 좋은 표면을 유지하며 2mm 이하의 미소 두께를 지속적으로 가공이 가능하도록 하였으며, 다양한 절삭조건, 2날과 4날 엔드밀 날수 변화 등을 통해 최적의 가공조건을 알아보는 실험을 진행하였다.
Recently magnesium alloy sheet has been used as a lightweight material in transportation area. Warm forming is a forming method that improves formability and reduces springback. The magnesium alloy sheet has a characteristic that large difference of flow stress increases depending on strain rate at high temperature. These characteristics cause low dimensional accuracy of formed products. In this study, experiments were performed on the 2D-draw bending with respect to the temperature and forming speed in order to investigate the effects of strain rate and temperature. It was found that as the temperature increases, spinrgback of 2D-draw bending decreased and formability of AZ31B increased. Additionally, the effect of the punch speed was investigated. At 250°C, as the punch speed increased, the springback of 2D-draw bending decreased.
In this study, attention has been focused on magnesium materials, which are widely used for lightening of electronic products and mobile phones. Therefore, a polishing apparatus was fabricated by replacing the SiC abrasive used for polished surface of magnesium plate with a ceramic abrasive. The following conclusions were obtained. It is believed that the increase in productivity of 50% compared to the conventional cross-sectional polishing due to the double-side polishing of magnesium sheet can contribute to increase the company's sales. The surface roughness was measured by polishing the plate using a magnesium plate mirror polisher. The Ra, Rmax and Rz values were 0.43, 0.54 and 0.54, respectively. In this study, the optimum polishing speed was 800 m/s when the surface was polished with a magnesium surface polishing device designed and manufactured as a prototype.