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钛在牙科中具有广泛的应用前景。但由于具有较高的熔点(1670±50℃),较低的密度,与氧、氢、氮、碳的高亲和性,以及与包埋材料特别是磷酸盐结合的SiO_2基包埋料较高的反应活性,因而使钛成为一种难 于铸造的金属。两室压差铸造技术中,影响铸件完整度和孔隙率的因素包括施加于熔金上的氩气压、包埋料的透气性、熔金和铸腔的温差等。本研究考察铸造压差对钛铸件孔隙率和机械性能的影响。 材料和方法制作长20mm。直径2.9mm的哑铃形塑料铸型24个,用磷酸盐结合的SiO_2基包埋料包埋、焙烧,用双室电弧氩气压铸造机铸造。先抽真空到7.9992Pa,在焙金室充氩,分别建立6666,19998,39996,59994 Pa的铸造压差,每种压差下铸造6个铸件试件,喷砂。试件摄X片,用计算机扫描系统对内部
Titanium has a wide range of applications in dentistry. However, due to its high melting point (1670 ± 50 ℃), lower density, high affinity with oxygen, hydrogen, nitrogen and carbon, as well as with SiO 2 -based embedding materials, especially with phosphate High reactivity makes titanium a difficult-to-cast metal. In two-chamber differential pressure casting, the factors that affect the integrity and porosity of the castings include argon pressure applied to the melt, air permeability of the embedding material, temperature difference between the melt and the casting cavity, and the like. This study investigated the effects of casting pressure on the porosity and mechanical properties of titanium castings. Material and method of production length 20mm. Twenty-four dumbbell shaped plastic molds with a diameter of 2.9 mm were embedded in a phosphate-bonded SiO 2 -based material and fired. The was cast with a two-chamber arc argon pressure casting machine. First vacuum to 7.9992Pa, argon in the baking chamber, respectively, to establish the 6666, 1999, 399996, 599994 Pa casting pressure, casting each casting 6 casting specimens, sandblasting. Specimens were taken in X-ray and the system was scanned internally by a computer