Microstructure Changes in TRIP Steel/Mg-PSZ Composites Induced by Low Compressive Deformation

Authors


  • This work was financially supported by the German Research Foundation (DFG) in frame of a research project within the Collaborative Research Centre SFB 799. Ms. S. Richter and Mr. H. Ahmad are acknowledged for their experimental support. The Institute for Iron and Steel Technology in Freiberg is acknowledged for providing us with the TRIP steel powder.

Abstract

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Strength and work hardening of TRIP matrix composite materials depend strongly on the testing temperature. Due to a temperature dependent driving force for the α′-martensite formation and a changing stacking fault energy in the metastable austenitic matrix, completely different deformation mechanisms can be observed at room temperature and at 100°C. With the transition from the formation of intrinsic stacking faults at 20°C to extrinsic stacking faults at elevated temperatures, the TRIP effect is substituted by mechanical twinning. The stress induced martensitic transformation in the reinforcing zirconia particles increases the stress level of the MMC further.

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