22.10.2001 Pressing & Sintering

Improvements in Bonding of Press-Ready Low-Alloy Steel Powder Mixes

EURO PM2001, in Nice, France. Authors: Fredrik Vinnerborg, Ulf Engström, Hilmar Vidarsson, Johan Arvidsson. In order to expand the applications for sintered structural components there is a continuous demand for development of new powders and processes which result in improved mechanical properties and precision of tolerances at reduced processing costs.  A wide range of different alloying elements and ways to add these are used in PM. As the way of adding the alloying elements influences both the mechanical properties and the dimensional scatter of the components after sintering it is important that press ready powder mixes are made in such a manner that the required mechanical properties are achieved without losing the dimensional precision. One way to secure this is to bond the constituents to the iron or steel powder. By efficient bonding, powder mixes less prone to segregation and dusting and with improved filling of the press tools can be prepared In this paper, low alloy steel powder mixes prepared with this new bonding concept are compared with conventional premix, both regarding tool filling behaviour and scatter of dimensional tolerances after pressing and sintering. The results are obtained in mass production trials.