In this paper, a controllable porosity porous stainless steel was prepared by gel⁃casting and microwave sintering. The gel⁃casting parameters, microwave sintering parameters, the shape factor of the powder and the powder size impact on the pore structure are investigated. The results show that the fluidity of the slurry performs the best and the dried green body has high strength at volume solids content of 56%, gelatin content of 1%, sodium alginate content of 0. 8% and the mixture pH value of 7. The material has good pore morphology at sintering temperature of 1 200 ℃ and holding time of 30 min. The increase of powder shape factor and the decrease of particle size results in a decrease of pore diameter and porosity with a uniform distribution. The porous stainless steel with porosity of 20%~ 35%and pore size of 10~30μm can be obtained with the particle size of 35~ 60μm and powder shape factor of 0.85~1.0. In conclusion, the porosity and average pore diameter of porous stainless steel can be controlled accurately by selecting different powder shape factor and particle size of powder with reasonable parameters of gel⁃casting and microwave sintering.%利用凝胶注模工艺结合微波烧结的方法制备孔隙可控的多孔不锈钢，实验研究了凝胶注模参数、微波烧结参数、粉末形状和粉末粒径等因素对孔隙结构的影响．研究表明：体积固相含量达56％，明胶和海藻酸钠含量分别为1％和0．8％，混合液pH值为7时，浆料流动性好，干燥后的坯体强度较高；烧结温度达1200℃，保温时间为30 min，孔隙形貌较好；原料的粉末形状因子越大，粒径越小，则多孔不锈钢的孔径和孔隙率越小，分布越均匀；采用粒径35～60μm，形状因子0．85～1．0的粉末，制备出的多孔不锈钢孔隙率为20％～35％、孔径为10～30μm，接近现有透气模具钢水平．通过选取不同粉末形状因子和粒径的粉末，以及合理的凝胶注模和微波烧结工艺参数，可以准确控制多孔不锈钢材料的孔隙率与平均孔径．
展开▼
