Improvement of Mechanical Properties of Tantalum–Tungsten Alloy by Multi-pass Low-Pressure Reciprocating Cold-Rolling Process Combined with Annealing Treatment

Under the annealing treatment of 900 ~ 1150 °C, the multi-pass low-pressure reciprocating cold-rolling (MLR-CR) process and less-pass high-pressure unidirectional cold-rolling (LHU-CR) process of tantalum–tungsten alloy were studied. The microstructure and mechanical properties under the two conditions were characterized and analyzed. The results show that the mechanical properties of MLR-CR process were obviously improved at the same annealing treatment conditions. Even under the annealing condition of 1150 °C, the yield strength of MLR-CR process still reached over ~ 370 MPa. The microhardness was maintained at 220-240HV, and the elongation was close to 48%. Compared with LHU-CR process, the comprehensive mechanical properties of tantalum–tungsten alloy was improved under the condition of MLR-CR process, which was mainly attributed to the fine microstructure of MLR-CR process. Under the same annealing conditions, the dislocation density increased and recrystallization phenomenon was delayed in MLR-CR process compared with LHU-CR process. The mechanical properties of MLR-CR process are improved by dislocation strengthening and grain refinement synergistically.