Abstract
It has been shown previously that the sintering of the plain iron powder compacts are accelerated by the small additions of phosphorus, and not accelerated by boron, sulphur or copper.
Moreover, it has been well known that iron-copper, mixtures assume different dimensional changes with the variation of copper contents and this phenomenon is called as "copper growth".
Experimental results have shown that the densification of iron-copper mixtures during sintering is accelerated by the small additions of phosphorus. Therefore, if the addition of phosphorus is enough to offset the expansion of the iron-copper compacts due to the copper growth, both the expansion and the shrinkage of the iron-copper compacts will not be observed by sintering. The addition of Cu3P also has the same effect as phosphorus.
