结合剂含量对纯钛支架铸造包埋料性能的影响研究

Effects of the Adhesive Agent Content on the Properties of the Investment for Casting Titanium Bracket

研究了纯钛支架包埋料中结合剂含量对纯钛铸造性能的影响,探讨了自制铸钛包埋料应用于临床的前景。测试不同结合剂含量包埋料的抗压强度和热膨胀性能,采用X射线衍射测试包埋料的相结构,将自制包埋料与德国某铸钛支架包埋料所铸造的纯钛试样同时进行SEM和EDS分析。X射线衍射结果表明,钛包埋料的主晶相为MgO。添加结合剂后包埋料的抗压强度和热膨胀率显著增加,结合剂含量为7.5wt.%时,包埋料的综合性能最优,其中抗压强度最高,达到8.61 MPa,热膨胀率为1.81%,可有效补偿钛在铸造过程中的固化收缩。自制包埋料所铸造的铸件表面较光洁,基本无粘砂,反应层厚度较薄,为10 μm,远低于德国磷酸盐系铸钛支架包埋料所铸造的纯钛试样(约110μm)。

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 signiifcantly 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 10μm, 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.%.