Investigations on Oxide Particles Formed during Sintering of CrMnNi‐Transformation‐Induced Plasticity (TRIP) Steel Powder Metallurgically Materials Using Automatic Feature Analysis

Abstract

The combination of powder metallurgical and ceramics‐derived processing enables the manufacturing of innovative metal components. Using high‐alloyed transformation‐induced plasticity (TRIP) steels facilitates the manufacturing of metal components with outstanding mechanical properties for advanced load applications. The oxygen affinity of some alloying elements promotes the formation of non‐metallic particles during sintering, which deteriorate the mechanical properties. Bulk specimens are prepared from a 17Cr7Mn6Ni‐TRIP steel powder using a ceramics‐derived extrusion process with organic binders at ambient temperature. Processing comprises the thermal binder removal in air and the sintering in pure argon or hydrogen atmospheres. The sintered specimens are analyzed for their amount and composition of non‐metallic particles using scanning electron microscopy (SEM) and energy‐dispersive spectroscopy (EDS). The focus of this article is on the automated particle identification and analysis using an automatic SEM‐EDS‐related device. The automatic feature analysis provides statistical information on the chemistry, size, and morphology. The particles mainly consist of Cr, Mn, Si, and O forming Mn2SiO4 and MnCr2O4. The number of particles mainly depends on the debinding temperature and on the sintering atmosphere. The use of a pure hydrogen sintering atmosphere significantly depresses the formation of MnCr2O4, whereas silicates remain stable under the applied atmospheric and thermal conditions.