HIGH-PRECISION MEASUREMENT AND ACTIVE CONTROL OF SOLIDIFICATION

点击翻译按钮获取中文摘要

This research project aims to establish the technology for processing and manufacturing of novel materials utilizing the precise measurement and active control of melting/solidification phenomena. The project involves 4 elemental research fields divided according to the material to be processed, and the results can be summarized as follows :(1) Concerning the processing of polymeric materials, a high-precision injection-molding process was proposed by utilizing a CO_2-Laser Irradiation, and its effectiveness was confirmed in molding of polymer products of sub-mum precision. In addition, a technique for measuring the thermal resistance at the boundary between mold surface and molded polymer was developed to obtain better understandings of the heat transfer between them. As a polymeric material with novel characteristics, high-speed spinning of fibers of non-circular cross-section was tested, and the mechanism of structure development in the cross-section of fibers was discussed based on … More the molecular orientation and heat transfer around the fibers.(2) Concerning the single crystal growth for semiconductor materials, melt flow interacted with the external electric/magnetic fields was examined from the micro-macro view points. The effect of electric conductivity of the crucible wall on the melt flow and heat transfer was studied under the external magnetic field. These results were adopted to obtain high-quality single crystals.(3) About the precise control of the solidification of steel slab in continuous casting direct rolling process, effective edge-heating method utilizing the convection-radiation conversion was examined. The results enable us to obtain the relation between the edge-heating effect and properties of the slab surface and the radiation convertor.(4) Concerning the fiber-reinforced composite materials, a method for measuring the thermal properties of the composite material was developed, and a correlation estimating the relation between the thermal properties and fiber/matrix materials was deduced. The correlation can be utilized for designing the thermal properties of the composite materials.In addition to those, thermal behavior of cooling media in trans-critical state was supposed to be utilized for heat transfer control in material processing, and fundamentals of the trans-critical phenomena were studied by a molecular-dynamics approach. Less