Effect of nanoscale multilayered structurization on hardness and wear resistance in Al-Cr-N coating

Abstract

Al-Cr-N coatings were deposited on Si substrate by unbalanced magnetron (UBM) sputtering with Al and Cr targets and Ar and N-2 reactive gases at substrate bias of -50V. At a fixed chamber pressure of 0.8 Pa, the microstructure of the coatings was changed from AlN/CrN nanoscale multilayered structure to (Al,Cr)N mixed single layered one with the increase of rotation speed of substrate holder. The residual compressive stress of AlN/CrN nanoscale multilayered coating was higher than that of (Al,Cr)N single layered coating. For the AlN/CrN nanoscale multilayered coating, the residual compressive stress was reduced with increase in total pressure of reactive gases. The AlN/CrN nanoscale multilayered coatings with higher residual compressive stress showed higher hardness and wear resistance.