连续梯度不锈钢多孔材料的制备及性能

Fabrication and properties of continuous gradient porous stainless steel

利用离心沉积工艺制备连续梯度不锈钢多孔试样时,没有使用基体,而是直接在模具中成形,然后脱模、烧结。试验对制备出的连续梯度不锈钢多孔材料的微观形貌、透气度及最大孔径等进行了分析,结果表明,选择合理的烧结制度可以有效避免试样在烧结过程中因各梯度层收缩率不同而引起的变形、开裂问题;国标规定的厚度范围内,最大孔径<60μm时,连续梯度多孔不锈钢试样的透气度要高于相同最大孔径条件下均匀多孔材料的透气度;另外,在保持相对较高透气度的前提下,连续梯度多孔材料有较大的试样厚度选择空间,此试验结果为连续梯度多孔材料在某些应用领域取代均匀多孔材料提供了试验依据。

304L stainless steel powder was used as raw material and the powder suspension with good rheology, appropriate solid content and suitable for centrifugal molding technique was prepared. Continuous gradient porous metal samples were fabricated without substrates by centrifugal molding technique and the microstrueture, maximum pore size and air permeability of the samples were analyzed. The results indicated that selecting appropriate loading pattern and rational sintering system can efficiently avoid deformations and cracks of the samples which easily occurred during sample sintering. The air permeability of the continuous gradient sample is higher than that of the homogeneous porous sample with the same maximum pore size. In addition, the continuous gradient porous materials have a wide thickness arrangement to choose with the relative high air permeability.