ABSTRACT

The sintering shrinkage of tapped powders and prior cold compacted specimens of sponge and water atomised iron powders was investigated. The behaviour of the tapped powders is only determined by the driving force and that of the green compacts is strongly affected by modifications caused by cold compaction, which introduce a structural and a geometrical activity that enhance the kinetics of shrinkage. While the tapped powders display only an isothermal shrinkage, the green specimens display an additional large and anisotropic anisothermal shrinkage which is independent on the surface area of the powders. The effect of prior cold compaction tends to run out during the heating step of the sintering cycle.

摘要

研究了丝锥粉末的烧结收缩率以及海绵和水雾化铁粉的先前冷压样品的烧结收缩率。轻敲粉末的行为仅取决于驱动力，而压坯的行为受冷压引起的改性影响很大，冷压引起的结构和几何活性增强了收缩动力学。轻拍的粉末仅显示出等温收缩，而绿色样品显示出额外的大且各向异性的等温收缩，这与粉末的表面积无关。在烧结循环的加热步骤中，先前的冷压实效果趋于消失。