Last modified: 2015-09-21
Abstract
This study presents an analysis of cracking on ceramic shell during burnout process to determine the maximum value of the hoop stress towards pattern itself and also hoop stress on ceramic shell. There are two types of the internal pattern structure whereby hollow and square in which built from portable Fused Deposition Modeling (FDM) technique with same thickness of ceramic shell. The technique used is Fused Deposition Modeling (FDM) machine was built based on ABS P400 material. Strain gauge is viable tool in which was attached on patterns and ceramic shells to determine the maximum value of hoop stress during experimental burnout process. This experimental were conducted with variant temperature started from 30°C until 150°C with increment of 5°C per minute. Moreover, experimental result shows that ABS P400 material strain was rose when subjected to increment of temperature and pressure. This phenomenon happened due to the different value of Coefficient Thermal Expansion (CTE) between the patterns and ceramic shell. In addition, experimental results shows that the maximum hoops stress is higher on the square internal structure compared to the hollow internal structure. The observation was made that glass transition temperature, Tg between 70°C to 110°C. It was observed that the shell cracks happened on ceramic shell.