Effect of Hot Rolling on the Microstructure and Properties of Dispersion-Strengthened W-La Alloy

The effects of different deformation processing routes (rolling and rotary forging) and temperature conditions on the microstructure and mechanical properties of W-1%La2O3 alloy wire were investigated. The results indicate that with increasing cumulative deformation (from ø22 mm to ø5.2 mm), the grain refinement efficiency of the “rolling + rotary forging” sequence is significantly superior to that of the “rotary forging + rotary forging” process. For the as-deformed ø5.2 mm W-La alloy bars, the material processed by “rolling + rotary forging” exhibited a higher Vickers hardness of 544.9 HV compared to that processed solely by rotary forging. Following annealing treatment, the hardness values of ø9.0 mm and ø5.2 mm bars produced via the “rolling + rotary forging” route were 467.2 HV and 460.4 HV, respectively. These values are notably higher than those obtained from the “rotary forging + rotary forging” process, which measured 446.1 HV and 433.5 HV for the corresponding diameters. In summary, this study systematically compares the effects of rolling and rotary forging processes on the microstructure and properties of W-La alloy, providing a valuable foundation for the future development of high-strength tungsten alloy wires.