In situ tensile deformation of TRIP steel / Mg-PSZ composites

摘要

Composite material on the basis of a TRIP (TRransformation Induced Plasticity) steel with zirconia particles as reinforcement was produced by powder metallurgical technology and conventional sinter process. The goal of such type of material is to obtain exceptional mechanical properties like high deformation energy absorption due to the combination of martensitic phase transformations both in steel and ceramic. The steel matrix was made of the commercial steel AISI 304, which shows a deformation-induced martensitic phase transformation from the austenitic phase (fcc) into the a'-martensite (bcc). The zirconia particles were partially stabilized with MgO and show a stress-assisted martensitic phase transformation from the tetragonal to the monocline phase. Flat specimens were tensile deformed in-situ in a scanning electron microscope in order to follow the damage behaviour of the material. Some zirconia particles were characterized before and after tensile testing both by backscattered electron contrast as well as by electron backscatter diffraction (EBSD) in combination with energy dispersive X-ray spectroscopy (EDS).