Abstract
Performance improvement that can be achieved by Cu infiltration is quantified in this paper. Tensile and fatigue properties of a Fe–2·0Cu–0·7C powder metallurgy steel were compared to the same alloy infiltrated with 8 wt-%Cu. Microstructural characterisation, using optical and electron microscopies, was carried out to understand the effect of Cu infiltration on mechanical properties. Cu infiltration improves the ultimate tensile strength by 40% by increasing the load bearing structure, decreasing the stress concentrations associated to open porosity and increasing the hardness of the steel matrix. Fractographic observations show the evidence of stress transmission from the sinternecks to the steel particles due to infiltrated Cu. The beneficial effect of Cu infiltration is less pronounced for the fatigue properties as the endurance limit is increased by 10%. This lower improvement is explained by crack initiating at the Cu/steel matrix interface.
Get full access to this article
View all access options for this article.