HfSi2 Hafnium Silicide
The properties of hafnium disilicide Hafnium silicide is a kind of transition metal silicide, which is a kind of refractory intermetallic compound. Because of its unique physical and chemical properties, Hafnium silicide has been successfully applied in the fields of complementary metal oxide semiconductor devices, thin film coatings, bulk structure modules, electrothermal elements, thermoelectric materials and photovoltaic materials. The nano materials show special electrical, optical, magnetic and thermoelectric properties, and even have potential application value in the field of catalysis. Features of hafnium disilicide The product has high purity, small particle size, uniform distribution, large specific surface area and high surface activity. Application fields Ceramic materials, production of various high temperature resistant components and functional components. Application of Hafnium silicide in material preparation
1. Preparation of SiC – hfsi2 – TaSi2 anti ablation composite coating. Carbon fiber reinforced carbon (C / C) composite is a new kind of high temperature resistant composite material with carbon fiber as reinforcement and pyrolytic carbon as matrix. Because of its excellent high-temperature strength, ablation resistance and good friction and wear properties, in the early 1970s, the United States carried out the research work on C / C composites for thermal structures, which made the C / C composites develop from the scorching heat protection materials to the thermal structural materials. As thermal structural materials, C / C composites can be used in structural components of gas turbine engine, nose cone cap of space shuttle, front edge of wing, etc. most of these components work in high temperature and oxidation environment. However, C / C composites are easy to oxidize and cannot normally be used in oxidation atmosphere above 400 ℃. This requires proper anti-oxidation protection for C / C composites, and the preparation of anti-oxidation coating is one of the main protective measures. The results show that the ablation resistance of C / C composites can be further improved when Zr, HF, Ta, TiB2 and other refractory metals are added to the carbon matrix. In order to understand the influence of HF and TA on the ablative properties of C / C composites, SiC – hfsi2 – TaSi2 anti ablation coating was prepared by embedding method. The ablation performance of the coating was measured by oxyacetylene ablation device.
2. Preparation of an organic electroluminescent device. Which includes an anode, a light-emitting layer, a cathode and a packaging cover which encapsulates the light-emitting layer and the cathode on the anode, the packaging cover comprises a silicon nitride layer and a barrier layer formed on the surface of the silicon carbide layer; the material of the barrier layer includes silicide and metal oxide, and the silicide is selected from chromium silicide, tantalum disilicide, Hafnium silicide, titanium disilicide and disilicide The metal oxide is selected from from magnesium oxide, aluminum oxide, titanium dioxide, zirconia, hafnium dioxide and tantalum pentoxide. The life of the organic light emitting device is long. The invention also provides a preparation method of organic electroluminescent device.
3. Fabrication of a Si Ge alloy based thermoelectric element. The SiGe based thermoelectric element is composed of an electrode layer, a SiGe based thermoelectric layer and a barrier layer between the electrode layer and the SiGe based thermoelectric layer. The barrier layer is a mixture of silicide and silicon nitride, and the silicide is at least one of molybdenum silicide, tungsten silicide, cobalt silicide, nickel silicide, niobium silicide, zirconium silicide, tantalum silicide and Hafnium silicide. The interface of the silicon germanium alloy based thermoelectric components is well bonded, no cracks and obvious diffusion phenomenon are found at the interface, the contact resistance is small, the thermal contact state is good, it can withstand long-term high-temperature acceleration test. In addition, the preparation method has the advantages of simple process, high reliability, low cost, no special equipment and suitable for large-scale production.
4. A kind of high temperature resistant and anti-oxidation cermet composite coating was prepared. The composite film is characterized by that the coating is composed of refractory metal, refractory carbide and intermetallic compound, and the coating thickness is 10 μ m ~ 50 μ M. The refractory metal is one or more of molybdenum, tantalum, zirconium and hafnium; the refractory carbide is composed of silicon carbide and one or more of tantalum carbide, zirconium carbide and hafnium carbide; the intermetallic compound is composed of one or more of molybdenum silicide, tantalum silicide, zirconium silicide, Hafnium silicide, tantalum carbide, zirconium silicide and hafnium carbide; the crystal structure of the coating is formed by amorphous and / or polycrystalline nanoparticles.