Boron-enhanced sintering of iron-molybdenum steels

Powder metallurgy steel compositions based on Fe-M-Mo-C mixtures provide a means to sinter to near full density and to high strength levels, Using a s ingle press and single sinter process, maximum sintered densities near 7.2g /cm(3) were obtained However. higher sintered densities can be attained thr ough the addition of boron, This study examines two boron-modified alloy st eels in terms of sintering densification with attention to the determinatio n of mechanical properties, One route considered mixed elemental iron and m olybdenum powders while a second route started with a prealloyed iron-molyb denum powder. lo both cases, the powders were mixed with nickel, graphite, and boron, The difference in initial homogeneity in the molybdenum distribu tion impacted interaction with the baron, resulting in significant differen ces in densification and a large disparity in final mechanical properties, due primarily to grain boundary formation of borides in the mired elemental compositions.