Direct Investment Casting For Pattern Developed By Desktop 3D Printer

Abstract

Development of RP technologies has encouraged rapid study on portable 3D Printer in which there are varieties of portable 3D printer machines in market. Nevertheless, less reports regarding its consumption of fabricated pattern to be used in direct investment casting. This study has focused on development of ABS P400 pattern in terms of collapsibility behaviour which has capability to be used as sacrificial pattern in direct investment casting. In addition, the internal built structures have been built into two designs such as square and polygon patterns respectively. The patterns were constructed in semi cylindrical geometry which comes with one side opened and one side closed together wrapped with 4 mm of ceramic shell. This experimental were conducted with variation temperature starting from 30°C until 150°C with increment of 5°C per minutes while for the numerical simulation, the temperature selected was between 30 °C to 120 °C with 10 °C increment per minutes. Moreover, the observation was made that glass transition temperature, Tg happened near 110°C. It was observed that the shell cracking happened on the ceramic shell. Other than that, the polygon pattern tends to collapsed inwardly rather than square pattern during the burnout process. A result also shows that, there is significant amount of stress reduction on both square and polygon which was 45 % respectively. Besides that, the amount of strain on pattern itself has shown about 9% reduction. Moreover, there is greater difference in terms of ceramic shell strain reduction which was 38% for square and polygon patterns respectively. Lastly, there is 11 % reduction of strain when compared square and polygon in terms of axial strain on ceramic shell