Surface Analysis of Prealloyed Steel Powders: Qualitative and Quantitative Aspects

Paper in proceeding, 2010

The amount of oxides, and their composition and spatial distribution within a particle, determine the usefulness and subsequent processing requirements of a powder. The present work summarizes possibilities of qualitative and quantitative analysis of powder surface chemistry and its changes during sintering by a variety of methods, starting from surface-sensitive chemical analyses by XPS, Auger spectroscopy, HR SEM+EDX analysis etc. Utilizing modern thermoanalytical techniques such as DTA, DSC and TG combined with continuous chemical analysis through mass-spectroscopy allows identification of temperature ranges within which degassing and deoxidation of powder occur. The aim of this study was to establish a relationship between the surface composition of the powder and the type and extent of surface chemical reactions during degassing and deoxidation studied by thermoanalytical techniques performed on the same material. A number of water-atomized powders prealloyed with manganese (0.3-1.8%) were chosen as model materials for which qualitative and quantitative analysis of oxides is presented.