If you are looking for high-quality products, please feel free to contact us and send an inquiry, email: brad@ihpa.net
iron foam is a metal structure which combines much of the strength of solid metal with its lighter, porous microstructure. It is being explored for its potential to improve weight-stiffness ratio as well as energy dissipation and mechanical damping characteristics, among others.
Foamed steel is created by inserting hollow glass spheres into metal powder used in conventional metal injection molding (MIM). This type of PM process enables the fusion of the spheres with the surrounding iron particles without significant demixing under normal shaping temperatures and pressures.
The present study investigates the influence of thermo-chemical surface hardening treatments, in particular carburizing and carbonitriding – both of which are frequently employed in gear wheel technology – on the structural integrity and performance of iron matrix syntactic foam. The results show that, despite the pore size difference between the metal matrix and the spheres, the foam can be subjected to both processes at parameter settings typical for non-porous materials. Moreover, the effect of these processes on the metallurgical properties is comparable to that on non-porous materials.
In terms of the bending test results, both the carburized and carbonitrided foam samples achieve higher bending limits than the as-sintered reference samples. This is due to the fact that both heat treatment processes significantly increase the elastic modulus of the porous samples, which allows the bending stresses to be transferred with a greater degree before the material starts to exhibit plastic instability and crush. The resulting force-deflection curves illustrate this behavior, with the curved area increasing at a constant rate after the elastic region has been reached.