2D and 3D SIMS investigations on sintered steels

Powder metallurgy (PM) is a well-established method for manufacturing ferrous precision parts. Sintering is one of the important production steps and can be strongly enhanced (activated) by formation of a liquid phase during the sintering process. The liquid phase can be reached by the addition of alloying elements (e.g., copper) or sintering activators (e.g., phosphorus) and is formed by melting of eutectic phase mixtures or by incipient melting. The main investigations presented in this work are done by secondary ion mass spectrometry (SIMS): 2D and 3D elemental distribution. Additionally, impact energy and hardness measurements were performed in order to study the influence of phosphorus on mechanical properties. The concentration of P in different samples was varied between 0 and 1 weight percent (wt.%), the carbon content was consistently 0.5 wt.%. Nominal specimens were sintered at 1120 and 1250 °C in protective atmosphere of flowing nitrogen to determine the influence of sintering temperature.