连续梯度不锈钢多孔材料烧结变形分析

Analysis on Sintering Deformations of Continuous Gradient Porous Stainless Steel

摘要:

采用模压成形工艺制备连续梯度不锈钢多孔材料。试验对所制备的不同厚度连续梯度不锈钢多孔试样的收缩率及微观形貌进行了分析。结果表明：通过烧结试样的几何轮廓证实连续梯度多孔试样烧结后发生变形——相邻梯度层烧结应力的不同造成圆柱状试样烧结后变成圆台状；烧结过程中连续梯度多孔试样相邻梯度层间力的作用能够促进粉末烧结，对试样的烧结收缩产生影响，并且，粉末粒度越小，这种影响越明显；选择合适的级配粉末以及梯度层间合理的粉末体积或质量搭配，通过不同梯度层间烧结应力的相互抑制作用，可以实现同步收缩烧结，有效解决连续梯度不锈钢多孔材料烧结过程中出现的变形、开裂问题。

Abstract:

The continuous gradient porous stainless steel material was fabricated by compression moulding forming technique. The shrinkage ratio and the microstructure of the prepared samples with different thickness were analyzed. The results indicate that the continuous gradient porous samples were deformed after sintering confirmed by their geometric contour, i.e. the initial cylinder samples became truncated cone shape due to different sintering stress between the adjacent gradient layers. The stress between two adjacent layers can promote powder sintering and influences the sintering shrinkage during sintering. In particular, the smaller the particle size is, the more obvious the influence is. The proper particle size distribution and the reasonable match of the bulk or mass of powders between different gradient layers can avoid the sintering deformation and cracks by the mutual suppression of the sintering stress among the different gradient layers to realize synchronous shrank sintering.