In order to predict the powder flow law of the injection molding process of MgTiO3 ceramic parts with complex structures,a constitutive model and numerical simulation method for MgTiO3 ceramic injection molding were e...In order to predict the powder flow law of the injection molding process of MgTiO3 ceramic parts with complex structures,a constitutive model and numerical simulation method for MgTiO3 ceramic injection molding were established based on the Hunt method.The material parameters of MgTiO3 such as elastic modulus,Poisson ratio,glass transition temperature,thermal conductivity and specific heat capacity were measured.Based on the fitting curve and the material parameters measured,the cross-WLF viscosity model and P-V-T model required for MgTiO3 ceramic injection molding were optimized.Furthermore,the influence of process parameters on mold filling flow and distribution of parts defects was researched.It was found that the gate position,injection speed and melt temperature have greater influence on mold filling flow and the packing process has an obvious effect on parts’defects.On this basis,the MgTiO3 ceramic parts injection molding experiment verification was carried out.By comparing the experimental results with the simulated results,it is found that the deformation error is within 1.5%and the density error is within 1%.Therefore,this research provided theoretical guidance for the engineering application of MgTiO3 ceramic parts fabricated by injection molding.展开更多
An Al-3Ti-0.2C-1RE grain refiner was prepared by in-situ reaction method.The microstructure was investigated by optical microscopy(OM),scanning electron microscopy(SEM) equipped with energy-dispersive spectrometry(EDS...An Al-3Ti-0.2C-1RE grain refiner was prepared by in-situ reaction method.The microstructure was investigated by optical microscopy(OM),scanning electron microscopy(SEM) equipped with energy-dispersive spectrometry(EDS) and X-ray diffraction(XRD).The results show that the Al-3Ti-0.2C-1RE grain refiner is composed of α-Al,TiAl3,TiC and Ti2 Al20 Ce phases.Compared with Al-3Ti-0.2C refiner,the morphology of TiAl3 phase is changed and Ti2 Al20 Ce phases form with the addition of RE.Accordingly,the refining performance is improved.The phase forming process of the refiner is as follows: Blocky Ti2 Al20 Ce and fine blocky TiAl3 form in the melt at the initial stage of reaction,then the fine blocky TiAl3 gradually disappears,and the blocky Ti2 Al20 Ce grows bigger with the increase of holding time.The predominant mechanism to synthesize TiC particles is the reaction between high concentration of solute Ti atoms and graphite particles.展开更多
基金Project(2018CFB439)supported by the Hubei Province Natural Science Foundation,China。
文摘In order to predict the powder flow law of the injection molding process of MgTiO3 ceramic parts with complex structures,a constitutive model and numerical simulation method for MgTiO3 ceramic injection molding were established based on the Hunt method.The material parameters of MgTiO3 such as elastic modulus,Poisson ratio,glass transition temperature,thermal conductivity and specific heat capacity were measured.Based on the fitting curve and the material parameters measured,the cross-WLF viscosity model and P-V-T model required for MgTiO3 ceramic injection molding were optimized.Furthermore,the influence of process parameters on mold filling flow and distribution of parts defects was researched.It was found that the gate position,injection speed and melt temperature have greater influence on mold filling flow and the packing process has an obvious effect on parts’defects.On this basis,the MgTiO3 ceramic parts injection molding experiment verification was carried out.By comparing the experimental results with the simulated results,it is found that the deformation error is within 1.5%and the density error is within 1%.Therefore,this research provided theoretical guidance for the engineering application of MgTiO3 ceramic parts fabricated by injection molding.
基金Project(51174177)supported by the National Natural Science Foundation of China
文摘An Al-3Ti-0.2C-1RE grain refiner was prepared by in-situ reaction method.The microstructure was investigated by optical microscopy(OM),scanning electron microscopy(SEM) equipped with energy-dispersive spectrometry(EDS) and X-ray diffraction(XRD).The results show that the Al-3Ti-0.2C-1RE grain refiner is composed of α-Al,TiAl3,TiC and Ti2 Al20 Ce phases.Compared with Al-3Ti-0.2C refiner,the morphology of TiAl3 phase is changed and Ti2 Al20 Ce phases form with the addition of RE.Accordingly,the refining performance is improved.The phase forming process of the refiner is as follows: Blocky Ti2 Al20 Ce and fine blocky TiAl3 form in the melt at the initial stage of reaction,then the fine blocky TiAl3 gradually disappears,and the blocky Ti2 Al20 Ce grows bigger with the increase of holding time.The predominant mechanism to synthesize TiC particles is the reaction between high concentration of solute Ti atoms and graphite particles.
