14 results about "Phase formation" patented technology

The invention discloses a method for predicting phase forming ability based on machine learning of unbalanced data of high-entropy carbide ceramics, and belongs to the technical field of ceramic material design. The method comprises the following steps: constructing an initial data set by collecting literature data and experimental data of the phase forming ability of the high-entropy carbide ceramic in the existing research; performing oversampling on minority class samples in the data set by adopting an unbalanced learning strategy, and balancing the data set; performing feature engineering processing on the data set to obtain an optimal feature subset; a plurality of machine learning models are trained through the optimal feature subset, a prediction model is obtained through optimization, and the phase forming ability of the high-entropy carbide ceramic in the unknown phase component space is predicted through the prediction model. According to the method, the phase forming ability of the high-entropy carbide ceramic is predicted by combining unbalanced learning with a machine learning algorithm, and the prediction ability and generalization ability of the machine learning algorithm are remarkably improved.

Methods of forming patterned features on a surface of a substrate are disclosed. Exemplary methods include gas-phase formation of a layer comprising an oxalate compound on a surface of the substrate. Portions of the layer comprising the oxalate compound can be exposed to radiation or active species that form exposed and unexposed portions. Material can be selectively deposed onto the exposed or the unexposed portions.

The invention belongs to the field of material forming, and particularly relates to a method for controlling the alpha-Si3N4 phase generation rate in a silicon powder nitriding process, which is characterized in that the time t for controlling the pressure in a sintering furnace to be reduced from a high point P2 to a low point P1 is taken as a target, and different working conditions are coped by coordinately controlling N2 gas flow, Ar gas flow, temperature and pressure parameters; finally, the silicon powder nitridation generation reaction rate is controlled. The adjustable range of coordinating and controlling the N2 gas flow, the Ar gas flow, the temperature, the pressure and other parameters is larger than that of controlling a single parameter, and the technical difficulties that the alpha-Si3N4 phase generation rate is difficult to measure and the alpha-Si3N4 phase generation rate is difficult to regulate and control through the single parameter are broken through. By controlling the generation rate of the alpha-Si3N4 phase in the sintering furnace, the content of the alpha-Si3N4 phase in the sintering reaction process is increased, and a basic raw material is provided for subsequent purification breakthrough of silicon nitride ceramic powder.

The invention discloses a preparation method of a high-entropy Kagome material HEV6Sn6, which comprises the following steps of: 1, mixing Ho, Gd and Tb rare earth powder with V and Sn metal powder, and grinding and uniformly mixing under the protection of Ar atmosphere to obtain uniformly mixed powder; 2, loading the uniformly mixed powder into an Al2O3 crucible, transferring the Al2O3 crucible into a quartz tube, and sealing the quartz tube; 3, heating, sintering and preserving heat; and 4, cooling the quartz tube, and centrifugally separating the redundant Sn fluxing agent to obtain the high-entropy Kagome material HEV6Sn6. According to the method, a self-fluxing agent method is adopted, three different rare earth elements Ho, Gd and Tb are doped into the vanadium-based Kagome material at the same time, all the rare earth elements are evenly distributed on rare earth sites, obvious phase separation does not occur, the high-entropy Kagome material HEV6Sn6 is successfully constructed for the first time, introduction of new impurities can be avoided, phase formation is simple, and the method is suitable for industrial production. The method is suitable for the field of novel high-entropy spinning anti-contusion materials.

Provided is an aluminum alloy forging material having high proof stress and capable of further improving creep characteristics. An aluminum alloy forging material according to the present invention contains 0.10 mass% to 0.25 mass% of Si, 0.9 mass% to 1.3 mass% of Fe, 1.9 mass% to 2.7 mass% of Cu, 1.3 mass% to 1.8 mass% of Mg, 0.90 mass% to 1.20 mass% of Ni, 0.01 mass% to 0.10 mass% of Ti, and 0.10 mass% or less of Zn, with the remainder being Al and inevitable impurities. Further, the proof stress in a tensile test at 180°C is 220 MPa or greater and, in a DSC curve obtained by differential scanning calorimetry, the S' phase formation peak area appearing in a temperature range of 200°C to 400°C is 1.8 J / g or greater.

The application discloses a multi-principal-element low-modulus Ti-Zr-based medium-entropy alloy and a preparation method thereof. 100‑ 10x Nb 4x Ta 4x Hf 2x Wherein, 1<=x<=4. The application is based on the synergistic effect between the TiZr alloy and the Hf, Nb and Ta alloys, the alloy molar ratio between the two is controlled, the mixed entropy and the valence electron concentration of the alloy are improved, the beta phase forming ability is enhanced, the elastic modulus of the alloy is reduced, and the ductility of the alloy is improved, so that the application scenarios of the alloy material are expanded.

The invention relates to a non-linear component transition continuous gradient material additive manufacturing method and system. The problems that a traditional component linear change functionally gradient material is prone to generating a brittle phase in a component sensitive interval and is insufficient in performance can be solved. The method comprises the steps of determining a gradient step size according to the part size, and calculating the component change rate of each layer based on the printing layer thickness and height; the full-component functionally graded material is prepared in a linear transition mode, and a brittle phase generation interval is recognized in combination with a microstructure characterization means; a component nonlinear transition mode is designed for a sensitive interval, element segregation and brittle phase generation are inhibited, and the interface bonding strength and comprehensive performance are optimized. Components of the gradient material prepared through the method are continuously controllable in any direction, component distribution is free of a mutation interface, the strength, the high-temperature oxidation resistance and the thermal fatigue life of the gradient material are remarkably better than those of a traditional linear gradient material, and the gradient material is suitable for aerospace, nuclear energy heat dissipation, biological implantation and other high-performance requirement scenes.

The application discloses a design method of a nano L12 phase precipitation strengthened FCC-based high-entropy alloy, and the method is characterized in that a method for predicting the formation of a matrix phase by calculating a thermophysical and chemical parameter alpha related to phase formation is combined with CALPHAD calculation to provide calculation assistance for designing the precipitation strengthened high-entropy alloy. The method comprises the following steps: defining suitable elements for forming a matrix phase and a precipitated phase from a thermodynamic database according to the influence of different elements on phase formation; selecting 136 alloys with different component types, and dividing the 136 alloys into single-phase FCC, single-phase BCC, FCC+BCC and SS+IM; combining four parameter combinations of |ΔH mix |, ΔS mix , T melt , VEC with atomic size difference to predict the formation of the FCC phase, obtaining the parameter range of the FCC matrix phase formation, and adjusting the suitable element ratio according to the parameter range; and adding L12 phase forming elements such as Al, Ti and Cu to introduce a second phase by using the 'addition' principle of alloy design, and optimizing the content of the added alloy elements by means of CALPHAD calculation combined with experiments. Finally, the FCC-based high-entropy alloy with high density nano L12 phase precipitation strengthening is prepared.

The present application relates to a nickel-based alloy, its preparation method and application, belonging to the technical field of alloy preparation; the nickel-based alloy includes: C, Si, S, P, Mn, Cr, Co, Al, Y, Hf, Ti and H, and the rest are nickel and inevitable impurities; by adding Al, Y, Hf, Ti and Si, Al generates an Al2O3 oxide film at high temperature, which can effectively hinder the inward diffusion of oxygen, nitrogen and sulfur, and improve the high-temperature oxidation resistance of the material; Y and Hf can improve the adhesion of the oxide film, the addition of Si generates some silicon dioxide on the basis of Al2O3, which can achieve the effect of pinning the oxide film, Ti can prevent internal oxidation of the material, make the silicon dioxide only form on the surface, and cooperate with Al, which is beneficial to reducing the nitridation of aluminum and promoting the formation of Ni3Al strengthening phase, effectively improving the oxidation resistance of the nickel-based alloy, controlling the content of each element, ensuring that the material has a high melting point and improving the ignition ablation resistance.

The invention relates to the technical field of preparation of transition metal carbide materials, in particular to a synthesis method of an M '1.33 R0. 67 M ''2AlC3 MAX phase and a preparation method of a two-dimensional M' 1.33 M'' 2C3 MXene material. Aiming at specific synthesis obstacles caused by high stability of carbides of high-inertia M elements such as Ta and the like, an R element is introduced as a phase forming accelerant, and a high-purity ordered MAX phase containing Mo and Ta elements, which cannot be obtained before, is successfully synthesized. The auxiliary phase forming effect of rare earth is critical and indispensable, and the effect is not necessary in an M element (such as Nb) system with high activity. The two-dimensional M '1.33 M ''2C3 MXene material which is prepared from the specific precursor, has an ordered vacancy structure and is high in performance has excellent conductivity, can be used as a carrier to be compounded with metal phosphide, and provides excellent electrocatalytic oxygen evolution performance.

This invention relates to the field of luminescent materials and discloses a dysprosium-activated garnet-based white phosphor, comprising Na, Dy, RE, Ga, In, and Ge, wherein the molar ratio of the metal elements is Na:Dy:RE:Ga:In:Ge = 1:2x:2 - 2x:2:1:2, where 0.01 ≤ x < 0.10, and x is the doping amount of dysprosium at the inert rare earth sites. The invention also discloses the dysprosium-activated garnet-based white phosphor and its preparation method, including: a. reduced solid-state synthesis reaction temperature: novel matrix... a. The solid-state synthesis reaction temperature is significantly reduced to the range of 1200-1250℃, and phase formation is achieved in just 3 hours with excellent crystallinity, thus reducing energy consumption and preparation costs; b. No co-solvent required: The preparation process of phosphors does not require the use of co-solvents, reducing environmental impact; c. One-step sintering synthesis: The preparation process is simplified to one-step sintering, improving preparation efficiency and the feasibility of the production process; d. No specific pressure and atmosphere requirements: The preparation process does not require specific pressure and atmosphere requirements, reducing the limitations and complexity of process conditions.

The invention discloses a preparation method for promoting phase formation of an REBCO superconducting material based on induction of a nucleating agent and the REBCO superconducting material. The method comprises the following steps that S1, RE2O3, BaCO3, CuO and a nucleating agent are weighed according to the stoichiometric ratio, the nucleating agent is REBa2Cu3O7, and the adding amount of the nucleating agent is 0.5%-20% of the total molar amount of REBCO; s2, mixing the mixed powder obtained in the step S1 to obtain uniform composite powder; s3, carrying out molding treatment on the composite powder obtained in the step S2 to obtain a green body; and S4, sintering the green body obtained in the step S3, and cooling to obtain the REBCO superconducting material. According to the invention, the nucleating agent with high lattice matching degree with the REBCO superconductive phase and good wettability is introduced into the REBCO basic raw material to play a role in promoting phase formation of the REBCO superconductor.