Prediction of Formability of Aluminum Alloy 5454 Sheet

Key Words: Formability(성형성), Aluminum Alloy(알루미늄합금), Plastic Instability(소성불안정), FormingLimit Diagram(성형한계도)초록: 자동차산업에서대기오염을줄이고연비를향상시키기위해경량화가중요한과제로여겨지고있다. 이를위해알루미늄소재의적용이증가하고있다. 판재를차체에적용하기위해서는주로프레스가공공정을거치게된다. 이때, 재료, 제품설계및프레스공정의부적절한가공변수의사용으로인하여파단, 주름, 및스프링백등에의한다양한형태의가공불량이발생한다. 따라서이들변수들의적절한조화뿐만아니라엄격한공정관리가요구된다. 이에본연구에서는자동차판재에주로사용되는Al5454 재료에대한이론적으로유도한소성불안정조건을구하고, MATLAB을이용하여성형한계도를도출하였다. 또한, 장출인장실험을통해얻어진실험값과이론적으로도출한성형한계도와의비교를수행하였다.Abstract: In the automobile industry, reducing the weight is the most important objective for reducing airpollution and improving the fuel efficiency. For this reason, the application of aluminum sheets is increasing.When the sheets are applied to the automobile, using inappropriate variables for the material, product design,and press processing can generate tearing, wrinkling, and spring-back problems, which are the main types offailure in the manufacturing process. Therefore, it is necessary to reduce these failures by harmonizing themany variables and strictly managing the processes. In this research, we study the theoretical plasticityinstability of Al5454 and obtain the forming limit diagram (FLD) using MATLAB. Moreover, we comparethe theoretical FLD with an experimental FLD obtained from a stretching test.