The ceramic injection molding technique was used in the gas-pressure sintering of ultra-fine Si3N4 powder. The feedstock＇s flowability, debinding rate, defect evolution, and microstructural evolution during productio...The ceramic injection molding technique was used in the gas-pressure sintering of ultra-fine Si3N4 powder. The feedstock＇s flowability, debinding rate, defect evolution, and microstructural evolution during production were explored. The results show that the solid volume loading of less than 50vol% and the surfactant mass fraction of 6wt% result in a perfect flowability of feedstock; this feedstock is suitable for injection molding. When the debinding time is 8 h at 40°C, approximately 50% of the wax can be solvent debinded. Defects detected during the preparation are traced to improper injection parameters, mold design, debinding parameters, residual stress, or inhomogeneous composition distribution in the green body. The bulk density, Vickers hardness, and fracture toughness of the gas-pressure-sintered Si3N4 ceramic reach 3.2 g/cm^3, 16.5 GPa, and 7.2 MPa·m^1/2, respectively.展开更多
In this paper. zirconia is used as top mold material for Ti investment casting. Top mold samples are made by proper mold building technology. The effect of different sintering temperature on chemical composition, micr...In this paper. zirconia is used as top mold material for Ti investment casting. Top mold samples are made by proper mold building technology. The effect of different sintering temperature on chemical composition, microstructure and residual bending strength of the top mold sample is Studied. The volume and homogeneity of the air holes in the top mold are determined by sintering temperature. and finally determined the residual bending strength of the mold sample was determined.展开更多
基金financially supported by the National Nature Science Foundation of China (Nos. 51102024 and 21276028)
文摘The ceramic injection molding technique was used in the gas-pressure sintering of ultra-fine Si3N4 powder. The feedstock＇s flowability, debinding rate, defect evolution, and microstructural evolution during production were explored. The results show that the solid volume loading of less than 50vol% and the surfactant mass fraction of 6wt% result in a perfect flowability of feedstock; this feedstock is suitable for injection molding. When the debinding time is 8 h at 40°C, approximately 50% of the wax can be solvent debinded. Defects detected during the preparation are traced to improper injection parameters, mold design, debinding parameters, residual stress, or inhomogeneous composition distribution in the green body. The bulk density, Vickers hardness, and fracture toughness of the gas-pressure-sintered Si3N4 ceramic reach 3.2 g/cm^3, 16.5 GPa, and 7.2 MPa·m^1/2, respectively.
基金Tnts work was sureorted ac Outstanding abuts dation of Harbin institute Of Twhnology (No.99004)
文摘In this paper. zirconia is used as top mold material for Ti investment casting. Top mold samples are made by proper mold building technology. The effect of different sintering temperature on chemical composition, microstructure and residual bending strength of the top mold sample is Studied. The volume and homogeneity of the air holes in the top mold are determined by sintering temperature. and finally determined the residual bending strength of the mold sample was determined.
