31results about How to "Atomic radius is large" patented technology

The invention discloses a seven-element high-entropy alloy coating prepared by laser cladding and a preparation method thereof, belonging to the technical field of alloy surface coating modification; the high-entropy alloy powders are Al, Co, Cr, Fe, Mo, V, Ti . The matrix material is Ti-6Al-l4V (TC4) titanium alloy, and the atomic fraction of each raw material in the high-entropy alloy powder is Al (10%-16%), Co (11%-15%), Cr (9%-16%) ), Fe (6%-15%), Mo (8%-17%), V (8%-15%), Ti (12%-16%), the sum of all components is 100%. by CO 2 The high-energy laser beam emitted by the laser clads the configured alloy powder on the surface of the substrate to form a high-entropy alloy coating. The substrate and the cladding layer are metallurgically combined to achieve the purpose of surface modification, thereby increasing the hardness of the titanium alloy. , wear resistance and corrosion resistance, thereby extending the service life of titanium alloys.

The invention discloses an aluminum-silicon-magnesium casting alloy mechanical property improving method. Light rare earth is adopted and cooperates with heavy rare earth to process alloy melt, and the iron content is 0.09-0.20 wt% of the alloy melt mass. According to the improving method, based on the difference, in the aspect of physicochemical property, between light rare earth elements and heavy rare earth elements as well as the influence on the alloy crystallization process, the method of utilizing the light rare earth and the heavy rare earth to be combined and modified to control the microstructure and mechanical property of alloy is provided, the light rare earth and the heavy rare earth give play to advantage separately, namely, the light rare earth is focused on enriching on thealpha-Al and Si crystal solidification front and being adsorbed on the surface of crystal, and achieves the effects of refining and modifying; and the heavy rare earth is focused on adsorbing or conducting solid solution on iron-rich Al-Fe and Al-Fe-Si group harmful compound, influencing the microstructure of the compound, impeding growth of crystal, and promoting the compound to be decomposed into short rod-like shape or granular shape at the high temperature; and the light rare earth and the heavy rare earth achieve mutual complementarity in the aspect of controlling the microstructure of the alloy, and substantially, the quite good modifying effect is achieved.

The invention provides a preparation method of sucrose-6-benzoate, which comprises the following steps: by using sucrose as a raw material, methyl benzoate as an esterifying reagent and an alkali carbonate as a catalyst, synthesizing sucrose-6-benzoate under vacuum distillation conditions; and by using the polar difference between the sucrose and the sucrose-6-benzoate, adding a low-polarity solvent to precipitate unreacted sucrose, thereby purifying the sucrose-6-benzoate. The method can enhance the yield and purity of the sucrose-6-benzoate and recycle the unreacted sucrose, has the advantages of environment-friendly technique, low facility request and high economical efficiency, provides a new way for synthesizing sucrose-6-benzoate, and is suitable for the demands for large-scale industrial production.