Microstructure And Properties Of CuCrZr Alloy Processed By Equal Channel Angular Pressing

In present work, microstructure, mechanical properties, electrical conductivity and thermo-stability of CuCrZr alloy processed by equal channel angular pressing (ECAP) with differently initial microstructure were studied by means of scanning electron microscope(SEM),electron backscattering diffraction(EBSD), X-ray diffraction (XRD)analysis, transmission electron microscope (TEM), microhardness testing, mechanical testing,electrical conductivity testing and differential scanning calorimetry (DSC).Microstructure and grain size of as-ECAP processed CuCrZr alloy were significantly influenced by initial state and pressing temperature. When the aged CuCrZr alloys was processed at room temperature, the sample is characterized by uniform microstructure and the dispersively distributed second phase. When the solution-treated CuCrZr alloy was processed at 450 ?, the second phase distributed in Cu matrix uniformly. After eight passes, the grain size of aged CuCrZr alloy was reduced to about 5 ?m.When the CuCrZr alloy with differently initial states was processed at different temperatures, the microhardness of samples increased with the increase of pass number. When processed at room temperature, the electrical conductivity of samples decreased with the increase of pass number. When processed at 450 ?,the electrical conductivity of samples increased with increase of pass number.The initially aged CuCrZr alloy processed for 8 passes at room temperature has a good combination of mechanical properties and electrical conductivity with a tensile strength of about 580MPa and a electrical conductivity of about 71% I ACS. After processed for 8 passes at 450 ?, the initially solution-treated CuCrZr alloy has a good electrical conductivity with about 81% IACS. At the same time,it still has a tensile strength of about 550 MPa. Grain refinement has a small contribution to strength of CuCrZr alloy, which is about 20MPa. When processed at room temperature, dislocation strengthening mainly contributes to the strength of the initially solution-treated CuCrZr alloy, both dislocation strengthening and precipitate strengthening contribute to the initially aged CuCrZr alloy. When processed at 450 ?,the nano-precipitate has a major contribution to the strength of CuCrZr alloys, irrespective of the initial state.After softening at 300 ? for 2 h, CuCrZr alloy processed at room temperature has good mechanical stability, and the alloy processed at 450? shows good conductive stability.