多孔不锈钢的制备及其在注塑模具中的应用

摘要

通过凝胶注模与微波烧结方法制备多孔不锈钢,研究粉末固相含量对浆料和生坯性能的影响,比较冷冻干燥与传统干燥的效果,对比本文制备的多孔不锈钢与PM35多孔模具钢的内部孔隙与宏观性能,并将其用于注塑模型芯.实验结果表明:粉末固相含量为56％时,浆料流动性好,生坯强度高;与传统干燥方法相比,冷冻干燥后的生坯收缩更均匀,不易产生裂纹;与PM35多孔模具钢相比,本文制备的多孔不锈钢具有相近的孔隙形貌、孔隙率、平均孔径和透气率;利用多孔不锈钢型芯制作的注塑件表面粗糙度可达Ra1.1.凝胶注模与微波烧结法制备的多孔不锈钢可以很好地解决困气问题,同时保证注塑件的表面质量,简化模具结构,降低生产成本.%Porous stainless steel was prepared by gel casting and microwave sintering.Effects of solid content on the properties of slurry and green body were studied,and different results between freeze drying and traditional drying were compared.Macroscopic properties and internal porosities of the porous stainless steel were investigated and compared with PM35 porous mold steel,which was then served as injection mold core.The results show that optimum fluidity of slurry and high strength of green body can be accessed when solid content is 56％.Compared with traditional drying,shrinkage of the green body achieved by freeze drying is more uniform,and crack is seldom occurred.Pore morphology,porosity,average pore size and permeability of the porous stainless steel are similar to that of PM35 porous mold steel.Surface rough of injection part that produced via the PSS core can be up to Ra1.1.The porous stainless steel,prepared by gel casting and microwave sintering,can solve trapped gas problem.Meanwhile,it can ensure surface quality of injection parts,simplify mold structure,and reduce production cost.