Two improvements have been made on the calculation of plastic strain ratio(r value)inBCC monocrystals by considering the differences in the critical shear stres
50 keV B<sup>+</sup> ions was implanted to polycrvstalline with 50 keV B<sup>+</sup> to a dose o/ 3x10<sup>1</sup>7 ions/cm<sup>2</sup> at room temperature.The