WANG Jianqiang 1, LIN Cheng 2, ZHANG Jinling 3, LI Yingwen 3, GUO Litong 2
(1. Shanxi Xijing Medical Appliance Co., Ltd., Taiyuan 030024, Shanxi, China; 2. School of Materials Science & Engineering, China University of Mining and Technology, Xuzhou 221116, Jiangsu, China; 3. Shanxi Meiyuan Dentistry Appliance Co., Ltd., Taiyuan 030045, Shanxi, China)
Abstract: The effects of the adhesive agent content on the properties of the investment for casting titanium were studied. The compressive strength and thermal expansion ratio of the investment with different adhesive agent content were investigated. The morphology and composition of the reaction layer on the titanium casting’s surface were observed by SEM and EDS. The phase composition of the investment was studied by X-ray diffraction. The compressive strength and thermal expansion ratio of the investment were significantly improved by adding the adhesive agent. The highest compressive strength of the investment was 8.61 MPa when the adhesive agent content was 7.5wt.%. The corresponding thermal expansion ratio was 1.81%, which could compensate the shrinkage of titanium in the casting process. The thickness of the surface reaction layer of the titanium cast by the investment was 10 μm, which is much thinner than that of the titanium cast by a German commercial investment. Considering the compressive strength, thermal expansion ratio and surface reaction layer, the optimal adhesive agent content of the investment is 7.5wt.%.
Key words: titanium casting; Ti investments; compressive strength; thermal expansion; surface reaction layer