Precise measurement of physical properties of high melting point melts using microgravity environment

采用地球上最长、10秒、最高质量的微重力环境悬浮滴法测量高温熔体特别是液态硅的表面张力和密度。结果可概括如下：(1)微重力环境下高温熔体表面张力和密度的测量方法。(2)分析了表面张力引起熔体表面振荡模式。(3)本工作获得的表面张力值比以往的工作更可靠。(4)表面张力由于采用无容器工艺，在过冷条件下测量了液体硅的表面张力。(5)在本实验条件下，液体硅的表面张力不受气氛中氧分压的影响。(6)液体硅的表面张力和温度系数在熔点处分别为734 mN/m和0.069 mN/mK。(7)获得了计算表面张力的修正方程的适用范围。(8)必须控制液滴的位置来测量密度。悬浮滴法。

Surface tension and density of high temperature melts, especially liquid silicon were measured with the levitated drop method using microgravity environment which is the longest term, 10 seconds, and the highest quality on the earth.The results can be summarized as follows ;(1) A measurement method for surface tension and density of high temperature melts under microgravity environment.(2) Surface oscillation mode of melt caused by surface tension was analyzed.(3) Surface tension values obtained in this work were more reliable than those in previous works.(4) Surface tension and density were measured under supercooled condition because of containerless process.(5) Surface tension of liquid silicon was not affected by an oxygen partial pressure in an atmosphere in the present experimental condition.(6) Surface tension and its temperature coefficient of liquid silicon were 734 mN/m at the melting point and 0.069 mN/mK, respectively.(7) An applicable range of correction equation was obtained for a calculation of surface tension.(8) Positioning of liquid drop must be controlled to measure the density by the levitated drop method.