Abstract
In the present study, titanium powder was chosen as an expanding agent of an experimentally prepared resin-bonded calsia investment. The effect of Ti content on the dimensional change was investigated. In addition, the effects of the heating rate and heating temperature on the dimensional change of the investment were investigated during setting and after heating. The expansion increased with Ti content and the highest expansion (1.57%±0.58) was obtained at 10mass% Ti. The highest expansion was obtained at 900°C for 30min heating and was independent of the heating rate. These findings mean that the titanium powder in the calcia investment oxidized sufficiently at that heating condition. It was found that the developed resin-bonded calcia investment was able to compensate for casting shrinkage of pure titanium by adding some Ti powder to the investment.
