Deformation Mechanisms and Martensitic Phase Transformation in TRIP-Steel/Zirconia Honeycombs

The mechanical and structural response of powder metallurgical square-celled honeycomb structures to quasi-static and dynamic impact loads are described. By constructing the cellular lattice with a novel metal matrix composite material based on a metastable high-alloyed austenitic TRIP-steel particle-reinforced by magnesia partially stabilized zirconia (Mg-PSZ), high specific yield and ultimate collapse strengths as well as a high ductility and an enhanced specific energy absorption were gained. In order to prove the temperature sensitivity of the honeycomb structures, a selected low-reinforced composite condition was investigated in a pre-series of quasi-static compression tests at temperatures in the range between -190 and 150 degrees C. The present study shows that the deformation mechanisms of the TRIP-matrix composite honeycomb structures can be classified with respect to strain rate and deformation temperature, including the failure characteristics and the strain-induced a'-martensite transformation in the austenitic steel matrices ensuring the TRIP effect. The evolution of the a'-martensite phase content in the central crush zone of the TRIP steel and TRIP-Matrix Composite honeycombs is demonstrated based on the results of magnetic balance measurements.