Microstructure and deformation mechanism of Ag-12Â wt% SnO2 composite during hot compression

•Hot compression behaviours of Ag-12 wt%SnO2 composite were studied on Gleeble−3500 machine.•Hot compression induced the dispersive distribution of SnO2 particles in the Ag matrix.•Microstructure and deformation mechanism of the composite during hot compression were discussed.

Hot compression behaviours of Ag-12 wt% SnO2 composite were studied on Gleeble−3500 machine at temperatures of 700-850 °C and strain rates of 0.001-1 s−1, the flow stress constitutive equation of the composite during hot compression was established and the microstructure evolution was characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results showed that the flow stress decreased with an increase of the deformation temperature, but increased with an increase of the strain rate, and the serrated flow stress fluctuation happened on the true stress-true strain curves at a strain rate of 1 s−1. SnO2 particles were mainly distributed along the extrusion direction before hot compression, and were dispersively distributed in the Ag matrix after hot compression. Formation of the twins in the Ag matrix and some SnO2 particles was mainly responsible for the serrated flow stress fluctuation. The combined action of dynamic recrystallization and twinning was the main deformation mechanism during hot compression of the Ag-12 wt% SnO2 composite.

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