The influence of different negative current density on oxidation film thickness and dense layer thickness was studied. According to the results and experimental phenomenon，the negative current was adjusted steply, and the dense layer with high rates for 70% of micro-arc oxidation film was achieved. EDS and X-ray diffraction were used to analyse the composition and phase structure of the surface layer and the dense layer of oxide film .The friction coefficient and wear of the surface layer and the dense layer of oxide film were measured by wear machine measurement ,and were compared with hard anode oxidation film. The results show that the oxidation film thickness and the dense layer thickness increase with the rising of negative current density.The micro sparks can be avoided out, through adjusting negative current and a high dense layer of MAO film is got .The dense layer of MAO film contains only oxygen and aluminum elements, so it can not be effected by the electrolyte composition .The alpha Al2O3 level of the dense layer is higher than that of the surface layer, and the friction coefficient and abrasion loss of the dense layer is the lowest among the surface layer and hard anode oxidation film.

Ti-Al-Si-N films were deposited on 1Cr11Ni2W2MoV steel at different N2 flow rates from 0 to 600 sccm by AIP using a Ti60Al30Si10 target. The effects of the N2 flow rates on the deposition rate, composition, microstructure, microhardness and adhesion property of the films were investigated by SEM/EDS, XRD, microhardness and scratch tests, respectively. The results show that the deposition rate of the films decreased initially and then began to increase at N2 flow rate higher than 300 sccm. The microhardness of the films increased with the N2 flow rate except a slight drop at 450sccm. The evolution of adhesion property of the films was very similar to that of microhardness. All the Ti-Al-Si-N films had B1 NaCl structure with (220) preferred orientation except that at 600 sccm. The effects of the N2 flow rate on the properties of the Ti-Al-Si-N films were discussed.