Preparation And Characteristics Of Multi-component Alloy Films

Traditional alloy composed of two or more kinds of metals or non-metals is defined to be a material with metal characteristics, after melting, sintering and dealing with other methods. Conventionally, alloys have been designed following the principle whereby only one major element in the main component, and then changing the properties by adding or reducing minor element. The excessive addition of alloy elements can bring about a large number of complex compounds, especially brittle compounds which can significantly reduce the mechanical properties of the alloys. Therefore, the traditional theory holds that the kinds of alloying elements should be strictly controlled. Recently, novel multi-element alloys were originated by Yeh, the multi-element alloys mainly consist of at least five principal elements, with concentrations between5at.%～35at.%and will result in high-entropy effect. This innovative theory pushes the development of alloys into a brand new area.In this study, TiWVNbMoZr and AlCrTiWNbTa metal and nitride films were prepared on Si (100) substrate by JGP-280single-target and JGP-450three-target magnetron sputtering system respectively. We have investigated the chemical composition, microstructure, surface morphology and physical behavior under different sputter power, substrate temperature, substrate bias, the flow ratio of N2by EPMA, XRD, AFM, SEM, and nano-indenter.The results from single-target magnetron sputtering system are as follows:1. It is found that the atomic fraction of all the elements in the films deposited under different sputter power, substrate temperature and the flow ratio of N2is in the range of10%-30%, in accordance with the definition of high entropy alloy;2. The films at different substrate temperatures remain an amorphous structure. The nitride films deposited at RN<20%have an amorphous structure while the films deposited at RN>20%show a FCC structure;3. The hardness and elastic modulus of the films increases with the increase of RN, the maximum hardness and modulus of TiWVNbMoZr nitride films is30.08GPa and370GPa respectively.The results of three-target magnetron sputtering system are as follows:1. The atomic contents of all the elements of the films deposited under different substrate bias is in the range of10%-30%. The deposition rate decreases with the increase of substrate bias. The hardness and elastic modulus of the films reach12.5GPa and180GPa respectively; 2. The AlCrTiWNbTa nitride films deposited at RN<20%are a metallic films with an amorphous structure. When Rn>20%,these nitride films show a FCC structure with8～15nm crystalline size;3. When Rn=0%～20%, the roughness of the films increases as the increase of RN, while the roughness shows an opposite trend when Rn>20%. The roughness keeps0.30.4nm at various N2ratio;4. The hardness and elastic modulus of the films increase as the increase of RN. The maximum hardness and modulus of AlCrTiWNbTa nitride films is22.1GPa and239.1GPa respectively.