The Influence Of Peak Power On Mechanical Properties On Cr And CrN Films Depositied By High Power Impulse Magnetron Sputtering

High power impulse magnetron sputtering (HIPIMS) technology can generate high ionization degree of target due to low duty cycle and high peak power of target. During the deposition process, the high ion bombardment to substrate makes the deposition of film with good quality and improved performance, such as high hardness and good adhesion strength etc... As a consequence, HIPIMS is widely used in deposition applications. The purpose of this paper was to explore the main factor that affect power of target and metal ionization degree mostly, and then chromium (Cr) and chromium nitride (CrN) films were deposited to study the influence of the peak power of film structure and mechanical properties.First in this work, the technological parameter like air pressure and the supply parameter like pulse width, frequency, voltage, current limiting resistor were changed to study the discharge characteristics and plasma components. The results showed that the current limiting resistor played a significant role on the regulation of peak power of target and it was the main factor influencing the ionization rate of target.Second, by adjusting the current-limiting resistor in the circuit, different peak power can be obtained. Then Chromium (Cr) films were deposited on Silicon (100) wafer and 316L SS substrates using HIPIMS at different peak power. The influence of target peak power on Cr films structure and mechanical properties were explored in detail. It was found that both the ionization degree of target metal and ion-atom flux ratio increased with the increasing peak power. From the XRD result, all Cr films were observed to have the same structure. The grain size and the surface roughness decreased with increasing peak power. At low ionization degree of metal target and low ion-atom flux ratio, the deposited Cr film had low compressive residual stress and low hardness but good adhesion strength. At higher ionization degree, Cr film was fabricated with a higher residual compressive stress in the film and high hardness but decreased adhesion strength.At last, chromium nitride (CrN) films were deposited at different peak powers based on the work of Cr films deposition. The influence of peak power on CrN film microstructure, surface morphology and mechanical properties were studied in detail. It was found that the ionization degree of target metal increased with increasing peak power. At different peak powers, all CrN had the diffraction peak of (200) and CrN (220). At higher peak power, a weak Cr2N (111) diffraction peak also appeared. With increasing the peak power, the grain size of CrN film increased gradually due to the rising of temperature on substrate. All CrN films deposited at different peak powers showed a good adhesion with 316 L stainless steel substrates. At higher peak power, the CrN film with good wear resistance and improved toughness were fabricated.