Research On Preparation And Properties Of ZrN/Al-Si-N Multilayer Films And Al-Si-C-N Composite Films

A series of Al-Si-N composite films, ZrN/Al-Si-N multilayer films, Al-Si-C-N composite films were prepared by reactive magnetron sputtering method. The effect of Si content on the microstructure and properties of Al-Si-N composite films were studied. The effect of modulation period and modulation ratio on the microstructure and properties of ZrN/Al-Si-N multilayer films, the mechanisms of hardening had also been investigated. The effect of C target sputtering power on the microstructure and mechanical properties of Al-Si-C-N composite films, the hardening mechanisms had been discussed.The main conclusions in this work are summarized as follows:The studies on the Al-Si-N composite films indicated that the intensity of diffraction peak of AlN (100) and AlN(110) first enhanced with the increase of Si content, then weakened and broadened gradually and diffraction peaks shifted to high angle as Si content exceeding 15.36at.%, coatings turned into nano-crystal gradually; The maximum hardness of the composite films was 27.9GPa when the Si content is 9.91at.%, solid solution strengthening and interface composites resulted in the increase of hardness of Al-Si-N composite films; The property of oxidation resistance of Al-Si-N composite films was enhanced as increasing of Si content which could exceed the temperature of 950℃when Si content was 20.12at.%; As the increasing of Si content, the average COF of Al-Si-N composite films at RT first descended and then ascended in small range, the COF reduced was mainly influence of the friction layer mixed by a-Si3N4, SiO2 and Si(OH)2, and the average COF at 750℃increased at beginning and then decreased, was smaller than the COF of the same Si content at RT, which was mainly influence of lubrication layer of oxides produced at the elevated temperature.The studies on the ZrN/Al-Si-N multilayer films indicated that there wasn't"template effects"of ZrN thin films changing lAl-Si-N from 0.36nm to 3.6nm when the thickness of ZrN was 5.0nm, and the non-isostructural coherent and epitaxial growth had been found between fcc-ZrN and hcp-Al-Si-N layers. The maximum hardness of the multilayer films was 35.31GPa when the thickness of Al-Si-N was 0.36nm, and the hardness of the films decreased gradually with the increase of the thickness of Al-Si-N layers. The average COF of the multilayer films at RT first ascended and then descended in small range, the minimum average COF of the films was 0.1873 when the thickness of Al-Si-N layers was 0.36nm; There was still the structure of the non-isostructural coherent and epitaxial growth between fcc-ZrN and hcp-Al-Si-N layers changing modulation periods from 2nm to 10nm when modulation ratio was 1. The hardness of the films increased at beginning and then decreased with the increase of the modulation periods, The maximum hardness of the films was 29.52GPa when the modulation periods was 6nm, the average COF at RT ascended slowly. The coherence stress mechanism and the different slip systems in the non-isostructure resulted in the increase of hardness of the multilayer films.The studies on the Al-Si-C-N composite films indicated that the chemical states of the films was still in the form of hexagonal phase in the addition of C element, the intensity of diffraction peaks of AlN (100) and AlN(110) weakened rapidly while there were the stronger peak of AlN (002), the weaker peaks of AlN(101), AlN(102) and Al3C4(104), the films grew in AlN (002) preferential orientation. All the diffraction peaks shifted to low angle as the increase of power of C target sputerring, then broadened and weakened gradually. The hardness of the films increased at beginning and then decreased with the increase of sputerring power of C target, the maximum hardness of the films was 41.78GPa when the power of C target sputerring was 50w. Grain refinement, interface composites and solid solution strengthening resulted in the increase of hardness of Al-Si-C-N composite films. C element of the Al-Si-C-N composite films could perfect the COF.