TMMOB Metalurji ve Malzeme Mühendisleri Odas ı E ğ itim Merkezi Bildiriler Kitab ı 1177 19. Uluslararas ı Metalurji ve Malzeme Kongresi | IMMC 2018 Mould Design Optimisation of Sand Cast Magnesium İlhan Aygün¹, Erhan Körpe¹, Özen Gürsoy², Eray Erzi², Derya Dışpınar² ¹VIG Metal, Kütahya, Turkey ²Istanbul University, Faculty of Engineering, Department of Metallurgical and Materials Engineering, İstanbul, Turkey Abstract Magnesium and its alloys are very difficult to cast due its affinity to oxygen. The casting has to be carried out under protective atmosphere. Yet, the selection of casting method by itself is not good enough to produce good quality cast parts. The runner and sprue design have to be calculated in accordance with Ten Rules of Casting so that defect free cast magnesium parts can be obtained. In this work, various mould designs were investigated with MagmaSoft optimisation tool was used. The correlation between experimental castings and simulation was found to be over 90%. 1. Introduction Casting of magnesium alloys is always a challenge. Its significantly high affinity to oxygen makes it difficult to control during melting and pouring processes. Magnesium is the lightest metal almost half of density of aluminum [1]. The alloying of magnesium with various elements improves its mechanical properties which may become close to aluminum alloys. Therefore, magnesium alloys are still the attractive choice of metals and research on casting of these alloys have increased over the past decade. It has high ductility and damping properties. Thus, combined with its specific strength, major application areas are automotive and aerospace parts [2]. The current alloys are expensive and have not reached the desired mechanical properties. Therefore, high pressure die casting, particularly hot chamber applications are quite common [3-4]. In this work, Zr grain refined ZE41 alloy was sand cast and its castability and mechanical properties were evaluated. 2. Experimental Procedure The chemical composition of ZE41 alloy used in casting trials is given in Table 1. The cylindrical part geometry was selected which is given in Figure 1. Table 1. Chemical composition of ZE41 (wt. %). Zn Zr Rare Earth Mg 3.7 0.7 0.8 Rem. Figure 1. Schematic drawing of the cast part. Casting experiments were carried out in an air tight- sealed unit where the melting furnace is on top with a stopper at the bottom of the crucible, and the cast part is placed underneath the stopper connected with the runner system to the sand mould as seen in Figure 2. This original design was proposed by Prof.Ali Kalkanli (METU, Ankara, Turkey). Figure 2. The casting unit. The casting temperatures were selected as 675 and 710 o C. Alphaset resin binder was used with silica sand. Magmasoft Simulation was used for optimization of casting parameters. 3. Results and Discussion