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Tungsten wire with high strength and toughness for silicon wafer cutting in photovoltaic industry is a new hot research content. In order to improve the strength and processing performance of tungsten wire, tungsten alloy containing 0.5 wt%La2O3 was prepared by powder metallurgy method. The hot deformation behavior and microstructure evolution of tungsten lanthanum alloy were studied. Studies have shown that the alloy is extruded to grow fine grains, and its texture structure mainly presents two directions. The grain size of the instability zone is too large, and there are obvious cracks. With the decrease of strain rate and the increase of temperature, the recrystallization ratio of the alloy increases gradually, showing a partial equiaxed grain structure. The recrystallization ratio reaches the maximum at 1600 °C/0.01s−1, but it is still not completely recrystallized. Lanthanum oxide gradually aggregates to the grain boundary during the hot deformation process, which improves the thermal deformation activation energy of tungsten. The Q value is about 410.018 kJ/mol, which improves the high temperature strength of tungsten alloy. The compressive strength of tungsten alloy at high temperature is about 10% higher than that of pure tungsten. Combined with the hot processing map, the optimum process parameters of tungsten alloy were determined to be 1400 °C–1600 °C, 0.01–0.05s−1. The φ35.5 μm ultra-fine tungsten wire was prepared according to this parameter. The microstructure of tungsten wire is uniform and dense, and there are no cracks and defects. The tensile strength of tungsten wire is extremely high, reaching 5723 MPa.

To explore the thermoformability of Mn–Cr–Ni–Co steel for ball mill liner, isothermal compression tests were performed on Mn–Cr–Ni–Co steel using a Gleeble-3800 thermal compressive testing machine. Flow stress curves at 900 °C–1200 °C and 0.01s−1∼10s−1 were obtained. Results show Mn–Cr–Ni–Co steel has obvious positive strain rate sensitivity, with peak stress decreasing with increasing temperature. A constitutive equation for Mn–Cr–Ni–Co steel was established using the Arrhenius model based on strain compensation, and fitted values were compared to experimental values. A hot working map for Mn–Cr–Ni–Co steel was established and analyzed. Hot working process parameters are: deformation temperature of 980∼1200 °C, strain rate of 0.04–1.78s−1, providing a basis for selecting the hot forging process of the ball mill liner. Forging and forming experiments of the ball mill liner were carried out using the optimal parameters of Mn–Cr–Ni–Co steel from the hot working map. The ball mill liner has good forming quality with a relatively uniform martensitic structure inside. Tensile and impact tests were performed on the ball mill liner. Compared to the mechanical properties of traditional cast Mn13 ball mill liners, results show the tensile strength increased by 159.75%, elongation by 18.8%, and impact capacity by about 16.7%.

Fe40Mn20Cr20Ni20 medium-entropy alloy (MEA) has a single-phase crystal structure with high strength and good ductility at room temperature. It is important to study the hot deformation behavior for this alloy at a partially recrystallized state for possible high-temperature applications. In this investigation, the tensile tests were conducted on sheet materials treated via cold rolling combined with annealing at strain rates of 1 × 10−3–1 × 10−1 s−1 and deformation temperatures of 573–873 K. And the hyperbolic sine model was used to study the relationship between the peak stress, deformation energy storage and Zener–Hollomon parameter (Z parameter) of Fe40Mn20Cr20Ni20 medium-entropy alloys under high-temperature tension. According to the Arrhenius-type model, the constitutive equation of the alloys based on the flow stress was constructed, and the deformation activation energy and material parameters under different strain conditions were obtained. Based on the power dissipation theory and the instability criterion of the dynamic material model, the power dissipation diagram and the instability diagram were constructed, and the hot working map with a strain of 0.1 was obtained. The results show that the hyperbolic sine relation between the peak stress and Zener–Hollomon parameters can be well satisfied, and the deformation activation energy Q is 242.51 KJ/mol. Finally, the excellent thermo-mechanical processing range is calculated based on the hot working map. The flow instability region is 620–700 K and the strain rate is 2 × 10−3–4 × 10−3 s−1, as well as in the range of 787–873 K and 2 × 10−3–2.73 × 10−2 s−1. The optimum thermo-mechanical window is 850–873 K, ε˙ = 1 × 10−3–2 × 10−3 s−1.