| TiAlN/Si3N4-Cu nanocomposite coatings were deposited on304stainless steelsheets by DC reactive magnetron sputtering in this paper. The effects of substratetemperature, negative bias voltage, the content of Si and Cu on the structure, hardness,adhesion property, toughness, abrasion resistance and anti-oxidation property ofTiAlN/Si3N4-Cu coatings have also been studied.The influence of deposition temperature on structure and properties ofTiAlN/Si3N4-Cu nanocomposite coatings have been studied. When the depositiontemperature increases from room temperature(RT) to250oC, it can be lead toreducing the number of micropores, increasing the density of coating, decreasing theintensity of TiN(111) and TiN(220) diffraction peak, increasing of the hardness andelastic modulus. The maximum values are15.3GPa and293.4GPa, respectively. Thescratch test shows that when the deposition temperature is RT,150oC and250oC, thecritical load of coatings is3.85N,3.45N and5.10N, respectively. The scratch curveof coating deposited at250oC is inconsecutive and low peaks of acoustic signal. Thefriction coefficient and wear rate of TiAlN/Si3N4-Cu coating deposited at250oC isthe smallest, the values are0.74and2.5×10-4mm3/N·m, respectively. The wearmechanism is main of adhesion wear, abrasive wear and oxidation wear.The effects of bias voltage on the microstructure and properties ofTiAlN/Si3N4-Cu coatings were investigated in the range of0V to-60V. With biasvoltage increased from0V to-60V, decreasing of the grain size and improving ofcompactness were observed from the SEM morphologies, and the deposition rate oftarget material is increased and then decreased. The depostition rate of coatingsdeposited at-20V is4.394×10-3mg·cm-2·min-1. Compared with others coatings, themicrohardness and elastic modulus of TiAlN/Si3N4-Cu coatings deposited at-20V is19.6GPa and256.2GPa, respectively. And its adhesion property and abrasionresistance is the best. The wear rate is2.5×10-4mm3/N·m.The influence of the Si content(0-5.9at.%) on the properties of TiAlN/Si3N4-Cunanocomposite coatings have been studied. Increasing Si content, the coating becomessmoother, denser and more refined. When the Si content is3.39at%, the propertyresistance to plastic deformation(H3/E2) of the coating reaches the maximum of0.11GPa. Indentation test indicated that its surface and cross-section morphology have many micro-cracks. The growth way of cracks is bending growing. The toughness ofcoatings is the best. The coatings of3.39at.%Si content have the best wear resistance.The main wear mechanism is adhesive. The high temperature wear resistance ofnanocomposite coatings is good.TiAlN/Si3N4-Cu coatings with different Cu contents were deposited on304stailess steel by reactive magnetron sputtering and the effect of Cu content onmicrostruture and properties of coating was investigated. With increasing coppercontent in the coatings, micropores disappear from the surface of TiAlN/Si3N4-Cucoatings and the densification of coating was improved. The preferred orientation ofcoatings changed from (111) to (220). The grain sizes reduce from46.6nm to8.2nm.The oxidation kinetic curves of coatings mainly follow parabolic rate law. Thephenomenon hints that the oxides have excellently oxidation resistance.TiAlN/Si3N4coatings have the best oxidation resistance. The incorporation of copperis weakening the oxidation resistance of coatings. High temperature wear experimentindicated that with adding of Cu content, friction coefficient of coating can reducefrom1.4to0.6, and the wear mass decrease from3.34×10-4mg/N·m to1.519×10-4mg/N·m. The reason that abrasion resistance improved with adding of Cucotent may also related to the diffusion of Al and product Al2O3. |
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