Effects of Bias Voltage on the Structure and Mechanical Properties of Thick CrN Coatings Deposited by Mid-Frequency Magnetron Sputtering

摘要

Thick CrN coatings were deposited on Si (111) substrates by electron source assisted mid-frequency magnetron sputtering working at 40 kHz. The deposition rate, structure, and microhardness of the coatings were strongly influenced by the negative bias voltage (V-b). The deposition rate reached 8.96 mu m/h at a V-b of -150 V. X-ray diffraction measurement revealed strong CrN (200) orientation for films prepared at low bias voltages. At a high bias voltage of V-b less than -25 V both CrN (200) and (111) were observed. Large and homogeneous grains were observed by both atomic force microscopy and scanning electron microscopy in samples prepared under optimal conditions. The samples exhibited a. fibrous microstructure for a low bias voltage and a columnar structure for V-b less than -150 V.