The critical resolved shear stress is the shear stress along the slip direction on the slip plane due to the effect of yielding when the single crystal starts plastic deformation. Under the action of critical resolved shear stress, dislocations can overcome resistance, start to multiply and move, and lead to the beginning of plastic deformation. Therefore, the critical resolved shear stress depends on the resistance (such as lattice resistance) encountered when the dislocation starts to move. It is a constant of materials and is related to the structure and purity of materials. The test temperature and deformation speed can also affect the measured critical resolved shear stress.
Fundamental of Material Science -> Performance basis of materials