Studies on Sintering and Melting Process of Powders by Laser Irradiation and Induced Heating Method

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The objectives of this research project are to establish a series of process design and control methodology which can be suitabiy applied to the material synthesis process, production process of functionally green body and sintering process. A series of researches yields results as follows.1. Development of fine ceramics as a functional material is reviewed in connection with powder technology. Significance of evaluation and standardization pointed out, and movement of hybridization in technologies and industries is introduced.2. Production of ultrafine particles by laser irradiation method has been studied from a view point of apparatus engineering. It is shown that simulation results based on Brownian coagulation model can explain particle growth mechanism. Heat transfer inside the substance is also analyzed by making use of unsteady heat transfer model.3. To characterize ceramics powders a few tens of material powders produced by different manufacturers have been subjected to the sa … More me ceramics production process. A series of data yields an empirical correlation between green density and their forming conditions. The correlation enables green densities to be predicted from tap density and compaction pressure.4. The quantitative correlation between green and sintered density has been found out to clarify the effects of process condition on them. It is shown that the sintered density can be correlated with the green density by simple expression, and that graphical analysis proposed can be help to under stand the effect of process conditions on sintered and green density.5. As a basis research of functionally gradient material, three kinds of technique are proposed which can smoothly and continuously vary the composition of formed material. In each technique the working conditions have been experimentally investigated to control the composition profile. The attractive feature of these technique is their simplicity, which thus facilitates their application to other material synthesis processes. Less