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 assistedmid-frequency magnetron sputtering working at 40 kHz.The deposition rate,structure.andmicrohardness of the coatings were strongly influenced by the negative bias voltage(V_b).Thedeposition rate reached 8.96 μm/h at a V_b of-150 V.X-ray diffraction measurement revealedstrong CrN(200)orientation for films prepared at low bias voltages.At a high bias voltage of V_bless than-25 V both CrN(200)and(111)were observed.Large and homogeneous grains wereobserved by both atomic force microscopy and scanning electron microscopy in samples preparedunder optimal conditions.The samples exhibited a fibrous microstructure for a low bias voltageand a columnar structure for V_b less than-150 V.