A Finite Element Analysis for Improvement of Shaping Process of Complex-Shaped Large-Size Silicon Carbide Mirrors

Abstract

In the gel-casting process, the proper selection of technological parameters is crucial for the final quality of a green body. In this work, the finite element method is used to investigate the mold characteristics in the gel-casting process, and the typical flow behaviors under different conditions are presented. Based on the distribution characteristics of temperature, pressure and flow field of gel polymer, the simulated results provide some possible reasons for the generation mechanisms of defects. Then, a series of simulations were performed to investigate the effect of process parameters on the molding quality of green gel-cast bodies. The results show that the decreasing loading speed can effectively reduce the number of defects and improve the molding quality. In addition, this paper presents a new technique by applying the exhaust hole to decrease the number of defects and, hence, improve structural integrity. The influence of the loading speed on the mold characteristics is well understood for the gating system with an exhaust hole, which suggests to us appropriate parameters for optimizing the molding design. This work provides a theoretical basis to explicate the generating mechanism of defects involved in the gel-casting process and acquires an optimized technique to produce a silicon carbide green body.

Advanced Casting Techniques for Complex-Shaped Components: Design, Simulation and Process Control

“…The reduction of defects and rework is achieved by the implementation of advanced casting processes that prioritise precise process control and simulation-driven approaches [9]. Consequently, the occurrence of flaws such as porosity, shrinkage, and inclusions can be mitigated.…”

Thermal Debinding Kinetics of Gelcast Ceramic Parts via a Modified Independent Parallel Reaction Model in Comparison with the Multiple Normally Distributed Activation Energy Model

“…With the continuous expansion of the application field of ceramic materials, higher requirements have been put forward for the shape, size, and forming accuracy of ceramic components. − Gelcasting technology has been confirmed to be the most effective method to achieve near net shaping of ceramic products with larger sizes and more complex shapes because it can improve the deformation shrinkage and post-processing difficulties of traditional ceramic green body molding methods. − …”