Microstructure Evolution of Tin Coatings Prepared by Dual-Pulse Power Magnetron Sputtering

Abstract

The type of power source and the deposition parameters directly determine the growth structure of the coating during the magnetron sputtering, resulting in the difference of the mechanical properties of the coating. High power impulse magnetron sputtering (HIPIMS) generates high-density plasma by high power pulsed power source, which leads to the coating with dense structure and excellent mechanical properties. However, the low deposition rate of HIPIMS reduces the coating preparation efficiency and affects its industrial application. Therefore, dual-pulse power magnetron sputtering technology has been developed to improve the deposition rate and quality of coatings. In this study, TiN coatings were prepared using DPPMS at different deposition times. The microstructure, deposition rate, residual stress and adhesion of TiN coatings were analyzed. The results showed that when only one target was used for deposition, the deposition rate of TiN coatings increased first and then decreased during the coating growth. When the deposition time was 80 min, the deposition rate reached the maximum value of 52 nm/min. After the deposition time of 80 min, the residual stress in the TiN coatings changed from compressive stress to tensile stress, resulting in a significant decrease in the deposition rate of TiN coatings. The microstructure of TiN coatings gradually changed from fibrous structure to dense columnar structure with the prolongation of deposition time. In addition, when the deposition time was 80 min, the TiN coating had low residual compressive stress (-0.2 GPa), high hardness (27.5 GPa) and elastic modulus (340 GPa), and excellent adhesion between the coating and the substrate.