A newly developed calcia/titanium modified magnesia-based investment mold for titanium casting

作者：Lai Pei Ling; Chen Wen Cheng; Wang Jen Chyan; Huang Ta Ko; Hung Chun Cheng^*

来源：Materials Science and Engineering: C , 2011, 31(2): 144-150.

DOI：10.1016/j.msec.2010.08.008

• Pure titanium
• Calcia investment
• Magnesia investment
• Casting

Calcia (CaO) investment has the high stability with melted pure titanium (Ti) but the poor manipulation usually leads to low success rate of complete castings. Magnesia (MgO)-based investment can produce the high success rate of pure Ti casting though. However, the MgO-based investment should be accompanied with Ti powder to meet the accuracy of Ti castings. In this study, a pure titanium casting using Ti powder modified MgO-based investment and 0.1-0.5 wt.% CaO additive was investigated. Experimental results showed that pure Ti cast with a modified MgO-based dental investment with Ti/CaO resulted in a higher success rate of the complete casting and a decrease in the interfacial surface reaction at high casting temperatures as compared to unmodified MgO-based investments with Ti powder. This newly developed Ti modified MgO-based investment and 0.1-0.5 wt.% CaO additives had an acceptable marginal accuracy with a marginal gap of less than 50 mu m: the 0.4 wt.% CaO additive gave the best accuracy. Based on a micro-chemical analysis, the addition of 0.1-0.5 wt.% CaO to the Ti modified MgO-based investment significantly reduced the reaction layers and casting defects in pure Ti casting, which had proven to enhance Ti-porcelain bonding: the investment modified with 0.5 wt.% CaO had the thinnest reaction layer.

• 出版日期2011-3-12