A Stydy about Investment for Titanium Alloy.

用氩弧熔炼压铸机在350 ℃下将纯钛浇注到五种不同的磷酸盐结合SiO_2熔模材料中。研究了嵌体铸件的网格铸造性能、嵌体铸件的匹配性、努普硬度和横截面显微组织。还测量了该投资品的凝固和热膨胀、抗压强度以及X射线衍射分析。尽管是同一种磷酸盐结合SiO_2型包埋料，但不同包埋料的浇注性、配合性和反应层厚度都有不同程度的差异。这一结果可能与这些投资的方石英/石英比，估计从热膨胀曲线。制作了石英型和方石英型磷酸盐粘结包埋料。熔融钛反应更严重的方石英型比石英型投资模具。

Pure titanium was cast into five different phosphate-bonded SiO_2 investment mold materials (at 350^ﾟC) with an argon-arc melting and pressure casting machine. The mesh castability, the fit of the MOD inlay castings, and the Knoop hardness and the micro-structure in cross-sections of castings were examined. The setting and thermal expansion, the compressive strength, and the x-ray diffraction analysis of the investments were also measured. The castability, the fit, and the thickness of reacted layer differed in degree among these investments, in spite of the same phosphate-bonded SiO_2-type investment. This result may be related to the cristobalite/quartz ratios of these investments, as estimated from the thermal expansion curves. Quartz-type and cristobalite-type phosphate-bonded investments were made. Molten titanium reacted more severely with the cristobalite-type than with the quartz-type investment molds.