FATIGUE PROPERTIES OF SINTERED IRON AND SINTERED STEEL DISTALOY AE+0.7C AFTER DEFORMATION AND COPPER INFILTRATION
Abstract
The influence of copper infiltration and cold deformation of 4 % on the fatigue properties of sintered iron (WPL) and sintered steel of the Distaloy AE type is analysed. The results showed that the above mentioned degree of deformation had only a moderate influence on the fatigue properties and strength in both of the investigated materials. In the case of the copper infiltrated sintered iron compacts the increase of the density from 7.1g.cm-3 to 7.6 g.cm-3 resulted in a twofold increase of the fatigue limit, i.e. from 75 MPa to 150 MPa, the ultimate tensile stress increased from 175 MPa to 382 MPa, while the hardness from 70 to 100 HV10. In the case of the copper infiltrated sintered steel Distaloy AE +0.7C the density also increased from 7.1 to 7.6 g.cm-3 but the fatigue properties and strength remained on the level of the as-sintered values, i.e. fatigue limit 220 MPa, tensile strength 650 MPa, hardness 200 HV10. Copper infiltration in this type of material resulted in microstructure modification, where a copper network was formed along the grain boundaries. The negative effect of the copper network on fatigue properties is eliminated by the positive effect of pores volume decrease and by pores morphology change.
Editors and press
AMS online
