Strain‐Rate‐Dependent Flow Stress and Failure of an Mg‐PSZ Reinforced TRIP Matrix Composite Produced by Spark Plasma Sintering

A composite consisting of 5 vol% MgO‐partially stabilized ZrO 2 particles (Mg‐PSZ) and a TRIP‐steel‐matrix (CrNiMn steel; transformation induced plasticity) was produced through Spark Plasma Sintering. The processed material was tested under compression at various nominal strain rates (4 × 10 −4  s −1 ; 10 −3  s −1 ; 1 s −1 , 10 2  s −1 ). Both, the pure steel and the composite showed a considerable plasticity and high strength due to the very fine grained steel matrix. The addition of 5 vol% ceramic particles led to a rise in the offset yield strength of 60 MPa till 90 MPa according to the applied strain rate. Up to a strain rate of 1 s −1 , no change in offset yield strength was measured. A strain‐rate of 100 s −1 leads to a rise in the offset yield strength of approx. 100 MPa. Both, the ceramic and an increase in the strain rate implicate to an early generation of microdeterioration. Limited by the interfacial strength of steel and Mg‐PSZ, failure occurs early at the interfaces, which is shown in a decrease in the work hardening. During the compression, especially at higher strain‐rates, adiabatic heating occurred and counteracted to the martensitic transformation.