铁粉压缩性的研究

根据Konopicky理论,铁粉在2-8tf/cm2范围内压制时,单位压力P与相对密度Rp有如下关系:P=Aln$\frac{{1-{\rm{Ro}}}}{{1-{\rm{Rp}}}}$。本文用该理论对编号为AS、AG、CD、TJ、YQ不同厂家铁粉的压缩性进行了研究。定了铁粉的粒度及其组成、松装密度、流动性,计算了铁粉退火前后A值及Ro值的变化。并以此对铁粉的压缩性进行了讨论。通过对等密度线的测定,查明了不同粒度铁粉的压坯密度变化,以及在不同压力下压坯密度变化的规律。
本工作说明,铁粉的筛分和合批对改善铁粉性能、扩大铁粉品种是有利的。而铁粉的还原退火对改善铁粉的压缩性,获得中、高密度压件是必要的。

A STUDY ON COMPRESSIBILITY oF IRON POWDER

According to konopicky's theory, the interrelation between specific pressure (P) and relative density (Rp) of iron powders compacted in a pressure range of 20-80kgf/mm2 can be defined by means of following equation:
P=Aln$\frac{{1-{\rm{Ro}}}}{{1-{\rm{Rp}}}}$
in present paper the compressibility of iron powders with the code name of AG, CD, T J, AS and YQ, etc. from different plants are studied by this theory.The composition,particle size apparent density and flowability of above iron powders have been determined and the changes of value A and Ro of iron powders before and after annealing have been calculated. The influence of above factors on the compressibility has been discussed. By measuring the equal density curves,the changes of compact density of iron powders with different particle size and different pressure were investigated.
The present has prove work that the sieve classification and blend of iron powders are useful to improve the qualities and extend the varieties of iron powders. The annealing process is necessary to improve the compressibility of iron powder and to get medium and high compact density.