Yield strength temperature dependence of tungsten nanosized crystals: experiment and simulation

Abstract

Regularities of the temperature effect on yield strength of nanosized tungsten crystals are ascertained. Experimental values of the yield strength of nanoneedles in the direction [1 1 0] are obtained using the high-field technology at the temperature range 17,4–862 K. It is found that in this range, decrease in strength of tungsten nanoneedles is about 30%. So low, compared with ordinary single crystals, susceptibility of nanoneedles’ strength to change in temperature is due to specific feature of mechanism of transition from elastic to plastic deformations in defect-free nanocrystals. To analyse this mechanism, molecular dynamic simulation of tensile of tungsten nanowire over the temperature range 3–2400 K has been utilized. The thermal fluctuation model of the temperature effect on the strength of nanosized crystals is offered.

Keywords:

• Nanosized crystals
• tungsten
• nanoneedles
• MD-simulation
• strength temperature dependence