抄録
There is an urgent need to establish a mold for dental precision casting of pure titanium which has an excellent biocompatibility. The present authors have already developed a useful mold composed of refractory ceramic particles as a material for the aggregate and metal particles as a material for controlling expansion due to oxidation during heating. In order to design a mold having much more excellent dimensional precision and favorable other characteristics for quality control of the casting, it is necessary to analyze fundamentally the relationship between the amount of expansion of mold and other factors, such as the void fraction, content of expansive particles, radius ratio of metal and aggregate particles, and binding strength between particles. The present investigation was undertaken to develop two kinds of personal computer programs for simulation of (i) a packing of different sized circles under a gravitational falling condition and (ii) an expansion due to specific expanding circles in such a packed bed as (i). For the simulation (ii) process, the two dimensional finite element method was used. Since there is a good correlation between the results from the present trial simulation and the experimental data, it will be possible in the future to analyze the expansion mechanism of the mold in detail, by applying these developed programs.
