钨粉经高压扭转后韧性及热稳定性观察（英文）

Observations on the Ductility and Thermostability of Tungsten Processed from Micropowder by Improved High-pressure Torsion

采用高压扭转法,在440℃对纯钨进行大塑性变形(HPT)。硬度测试表明试样表面纯钨经高压扭转后硬度HV高达11 500 MPa。差热分析(DSC)结果表明等效应变较小的试样再结晶温度较高(高于1450℃),等效应变较大的试样再结晶温度较低(约800℃)。XRD分析结果表明试样晶格应变达0.35%,晶格常数达0.3177 nm,位错密度达2.4×10^(15) m^(-2)。高压扭转可以使纯钨在低温下实现固结并具有高强度,一定的韧性和热稳定性。

Tungsten was subjected to severe plastic deformation at 440 °C using high pressure torsion（HPT） with an improved die-set. Microhardness measurements suggest an appreciable ductility level in tungsten after HPT with Vickers microhardness HV as high as -11 500 MPa. Differential scanning calorimetry（DSC） analyses show that samples with less strain have a higher recrystallisation temperature（greater than 1450 °C） than samples with more strain（-800 °C）. X-ray diffraction analyses indicate increases in lattice strain up to 0.35%, lattice parameter up to 0.3177 nm and dislocation density up to 2.4 × 10^15 m^-2. The current study introduces the improved HPT process as an effective route for the production of ultrahigh strength W with significant ductility and specified thermostability.