HiPIMS deposition of CuNiTiNbCr high - entropy alloy films: Influence of the pulse width on structure and properties

Abstract

In the process of high power pulsed magnetron sputtering, optimizing the ionization rate of plasma plays a pivotal role in enhancing the properties of films. Altering the pulse width can impact the ionization rate and particle energy in HiPIMS. In this study, we prepared the CuNiTiNbCr high-entropy alloy films by HiPIMS under different pulse widths. The influence of pulse width on target discharge and plasma ionization rate was investigated, followed by a comprehensive discussion of the films' structure and properties under various pulse widths. The film deposited at various pulse widths consisted of high-entropy alloy amorphous phase and Cu-rich FCC phase. Decreasing the pulse width resulted in an increase in the peak power of the target, elevating the ionization rate of sputtered particles and leading to higher compressive stress and a denser film structure. These increased compressive stress and dense structure make the film have higher toughness and better wear resistance. Notably, the film deposited with a pulse width of 200 μs displayed the best corrosion resistance due to its high content of the passivating element Cr and its dense structure. Consequently, adjusting the pulse width can effectively modify the ionization rate of sputtered particles and enhance the performance of the film.