214 results about "Al element" patented technology

The invention discloses an ultra-wideband carbon / boron doped high-entropy alloy wave-absorbing material which is prepared by adjusting Fe and Ni elements, adding Si and Al elements and doping a small amount of C or B. The specific component of the wave-absorbing material is (FeaCobSicAldNie) 100-xMx. In addition, the invention also discloses a preparation method of the wave-absorbing material, and the preparation method comprises the following steps: 1, high-entropy alloy smelting; 2, preparing high-entropy alloy spherical powder; 3, carrying out flaky treatment; and 4, stress relief annealing. On the basis of FeCoNi medium-entropy alloy, the content of the Fe element with low cost is increased, the content of the Ni element with high cost is reduced, the Si element and the Al element are added at the same time, then a small amount of non-metal C and B elements are doped to serve as interstitial atoms, lattice distortion is increased, the wave-absorbing performance and corrosion resistance are improved, and the ultra-wideband carbon / boron doped high-entropy alloy wave-absorbing material is obtained.

The invention discloses a nuclear zirconium alloy cladding high-temperature oxidation resistant composite coating and a preparation method thereof, and belongs to the technical field of nuclear zirconium alloy coatings. According to the preparation method disclosed by the invention, through component gradient structure design, Cr ion pretreatment activation, deposition of a pure Cr inner coating, deposition of a Cr70Al30 intermediate coating and deposition of a Cr50Al50 outer coating are sequentially carried out on the surface of a nuclear zirconium alloy cladding, and the Cr-Cr70Al30-Cr50Al50 composite coating zirconium alloy cladding with a three-layer structure is obtained. According to the method, outward migration of the Al element is effectively limited while the excellent anti-oxidation characteristics of the Cr and Al elements are fully utilized, the coating has the excellent high-temperature oxidation performance, and the requirement for the service performance of the surface coating of the zirconium alloy cladding at the extremely high temperature is met.

The invention discloses die steel powder with high corrosion resistance. The die steel powder comprises the following chemical components in percentage by mass: 17.0%-18.5% of Ni, 8.0%-9.5% of Co, 4.5%-5.0% of Mo, 1.8%-2.5% of Cr, 0.4%-0.7% of Cu, 0.06%-0.12% of Y, 0.6%-0.9% of Ti, 0.06%-0.12% of Al and the balance of Fe. The invention further discloses a gas atomization preparation method of the high-corrosion-resistance die steel powder. The gas atomization preparation method comprises the following steps: (1) burdening and charging; (2) vacuumizing and gas replacement; (3) staged smelting: carrying out medium-frequency induction heating on the smelting crucible, raising the temperature to 1650-1720 DEG C at the speed of less than or equal to 10 DEG C / min, and keeping the temperature for 15 minutes after the matrix alloy is molten; adding high-purity elemental metals of Y, Ti and Al elements through a secondary feeding device 5-8 minutes before pouring is started, and realizing uniform diffusion of the elements by matching with argon covering and stirring; (4) argon atomization; and (5) powder post-treatment. According to the powder, the corrosion resistance is greatly improved by reasonably designing the components and the percentage thereof. According to the powder obtained through the gas atomization preparation method, the corrosion resistance is larger than or equal to 700 hours, the oxygen content is smaller than or equal to 50 ppm, the density is larger than 99.8%, and therefore the requirements of high-end optical molds are met.

The invention discloses a low-temperature high-toughness austenitic stainless steel welding wire and a preparation method thereof, and relates to the technical field of welding materials, in particular to a welding wire with high-toughness mechanical properties of formed cladding metal in a low-temperature environment and a preparation method of the welding wire. The Ti element is introduced into the welding wire, the dosage relation of the Al element and the Ti element is controlled, and the mass ratio of Al to Ti is kept to be (5-10): 1; a proper amount of Al element can play a role in purifying a molten pool during welding work, a proper amount of Ti element can effectively stabilize an austenite phase, and therefore it is guaranteed that the welding wire has the basic welding capacity, and meanwhile after the welding wire is converted into cladding metal, the welding wire is not prone to deformation. The material characteristics and the like of the material can meet the use requirements at room temperature and ultralow temperature environment, that is, the material has and keeps good tensile property, impact property and the like, so that pipelines, containers and the like prepared from the material can be used for transmitting or loading special low-temperature materials such as liquid hydrogen, liquid helium and the like.

The invention belongs to the technical field of aluminum alloy materials and preparation thereof, and relates to a high-strength and high-toughness die-casting aluminum alloy and a preparation technology and application thereof.The aluminum alloy comprises Si, Mg, Cu, Mn, Zn, Fe, Cr, Ti, Zr, Sr, Sb, B, La, Ce, Be, P, smaller than or equal to 0.05% of other single elements, smaller than or equal to 0.15% of other impurity elements in total and the balance Al element, the content of Sr and the content of Sb cannot be larger than or equal to 0.005% at the same time, and the balance Al element. According to a singly-cast sample prepared from the high-toughness die-casting aluminum alloy, the tensile strength at the room temperature is 380-450 MPa, the yield strength is 250-350 MPa, the ductility is 3-8%, the brinell hardness is larger than or equal to 105 HB, the electric conductivity is larger than or equal to 19 MS / m, and the heat conductivity is larger than or equal to 140 W / m.K; and at the temperature of 200 DEG C, the tensile strength ranges from 280 MPa to 350 MPa, the yield strength ranges from 220 MPa to 290 MPa, and the ductility ranges from 5% to 10%.

The present invention belongs to the technical field of metal material design and preparation, and specifically relates to a double heterogeneous structure high-strength plasticity low-density steel and a preparation method thereof. The double heterogeneous structure high-strength plasticity low-density steel proposed in the present invention includes the addition of a large amount of Al elements, which can greatly reduce the material density, and introduces the non-shearable NiAl type B2 phase through Ni alloying, and forms a double heterogeneous structure through multiple rolling and annealing processes. The double heterogeneous structure low-density steel can have higher strength, greater plasticity and higher work hardening rate at a lower density. And the addition of Al and Ni elements can greatly improve the corrosion resistance of steel materials, and the preparation method is simple and economical, and can realize large-scale industrial production. The research and development and application of the finished steel have important economic value and social significance for promoting lightweight material design, improving strength and plasticity, reducing energy consumption, and reducing greenhouse gas emissions.

The invention mainly provides a nuclear fuel cladding composite material and a preparation method thereof. The nuclear fuel cladding composite material comprises a zirconium alloy matrix, the niobium-rich diffusion barrier layer is formed on the surface of the zirconium alloy matrix; the Cr coating covers the niobium-rich diffusion barrier layer; and an Al-rich layer formed on the surface of the Cr coating. The preparation method comprises the following steps: firstly, carrying out surface pretreatment on the zirconium alloy matrix; a niobium-rich diffusion barrier layer is formed on the surface of the zirconium alloy matrix through ion implantation; then depositing a Cr coating on the niobium-rich layer; and finally, an Al element is injected into the surface of the Cr coating, and an Al-rich layer is formed so that an Al2O3 protective layer can be formed under the high-temperature working condition. According to the technical scheme, interface mutual diffusion can be effectively inhibited, the stability of the coating is improved, meanwhile, the Cr coating structure is optimized, the oxidation process is delayed, a gradient protection system is constructed, and the oxidation resistance of a high-temperature material is enhanced.

The invention relates to a TiAl alloy additive manufacturing method. The TiAl alloy additive manufacturing method comprises the steps that TiAl alloy powder is selected; establishing a three-dimensional model; a scanning path is planned; when the section width of the part is smaller than the preset partition width, a standard scanning line length is adopted for scanning; on the contrary, the section of the part is subjected to region division, and the partition scanning line length is adopted for scanning; the standard scanning line is longer than the partition scanning line; and the TiAl alloy powder is loaded into a powder bin of electron beam additive manufacturing equipment, and scanning melting is carried out. According to the method, the content of the Al element in the TiAl alloy powder is controlled, so that the alloy solidification process is carried out according to a beta solidification path, and formation of fine isometric crystals is facilitated; by controlling the content of the B element, borides which are distributed in a dispersed mode are formed, and the effect of refining the microscopic structure is achieved; by setting the preset partition width, the partition lap joint width and the partition offset width, the structure and performance difference caused by remelting at the partition scanning lap joint is solved.

The invention provides an aluminum alloy wire and a preparation method thereof. The aluminum alloy wire comprises the following elements in percentage by mass: 0.1 to 7.0 percent of Zn element, 0.2 to 9.6 percent of Mg element, 0.1 to 6.0 percent of Cu element, 0.01 to 1.2 percent of Mn element, 0.1 to 2.0 percent of Fe element, 0.1 to 2.5 percent of Si element, less than or equal to 0.15 percent of inevitable impurities and the balance of Al element, the surface brightness L of the aluminum alloy wire is greater than 60, and the surface brightness color difference E is less than or equal to 0.5; the average roughness Sa is less than or equal to 0.4 mu m, and the maximum peak height Sp is less than or equal to 2.0 mu m; the aluminum alloy wire does not crack after 85% compression deformation; under the test conditions that the temperature is 35 DEG C, and the aluminum alloy wire is placed in a mixed solution of a 57g / L NaCl solution and a 10mL / L H2O2 solution to be soaked for 6 hours, the corrosion depth of the aluminum alloy wire is smaller than or equal to 10 micrometers.

The invention relates to the technical field of material protection, in particular to a lead-bismuth-resistant coating and a preparation method thereof.The coating is composed of a metal bonding layer, a functional transition layer and a corrosion-resistant layer, the metal bonding layer is formed by compounding a high-entropy alloy and a medium-entropy alloy, a component gradient transition structure is formed, the high-entropy alloy is a near-equal-atomic-ratio alloy of Fe, Co, Ni, Cr and Al, and the medium-entropy alloy is a near-equal-atomic-ratio alloy of Fe, Co, Ni, Cr and Al. %, and the medium-entropy alloy is a FeCoNiCr system quaternary alloy, and the content of the Al element is 5-10 at. The functional transition layer is a transition metal nitride layer; and the corrosion-resistant layer is an eutectic composite layer of rare earth oxide and stabilized oxide. Therefore, the problems of insufficient bonding strength, limited corrosion resistance, poor process stability and the like in the prior art are solved.

The invention discloses a preparation method of an ultralight high-performance flame-retardant magnesium-lithium alloy bar, which comprises the following steps: 1) smelting a magnesium-lithium alloy raw material, and casting and molding; (2) the magnesium-lithium alloy cast ingot is preheated and subjected to hot extrusion forming; and (3) the magnesium-lithium alloy extruded bar is subjected to deformation treatment of cold rotary swaging, and the ultra-light high-performance flame-retardant magnesium-lithium alloy bar is obtained. The Al element for improving the mechanical property of the alloy and the Ca element for improving the flame retardant property of the alloy are added into an Mg-Li alloy system, the comprehensive performance of the magnesium-lithium alloy is cooperatively regulated and controlled, meanwhile, the atomic number of the Al element and the atomic number of the Ca element are low, and when the Al element and the Ca element are added into the magnesium-lithium alloy, the characteristics of the ultra-light structure alloy of the magnesium-lithium alloy are kept; meanwhile, the subsequent extrusion-rotary swaging composite deformation process is combined to improve the mechanical property of the alloy, the alloy has excellent mechanical property at room high temperature, and the room temperature tensile strength of the alloy series is 210-240 MPa; the elongation rate is 4.1 to 5.1 percent; the performance is stable at the medium-high temperature of 100 DEG C, and the tensile strength is 160-240 MPa; and the elongation rate is 17.2 to 22.1 percent.

The invention discloses a high-strength and high-conductivity copper alloy and a preparation method thereof. The high-strength and high-conductivity copper alloy is prepared by mixing Cu-Al pre-alloyed spherical powder and CuO powder according to the mass ratio of (100-400): 1. The mass fraction of Al in the Cu-Al pre-alloyed spherical powder is 0.1-0.5%, and the balance is copper; the Al element in the solid solution state in the high-strength and high-conductivity copper alloy is partially oxidized into Al2O3 through CuO and exists in a Cu matrix in the form of Al2O3. The preparation method comprises the following steps: (1) powder mixing: firstly mixing Cu-Al pre-alloyed spherical powder with CuO powder, and then carrying out vacuum drying; (2) isostatic pressing treatment is conducted, specifically, the mixture is injected into a mold, and hot isostatic pressing treatment is conducted after cold isostatic pressing forming is conducted; and (3) carrying out hot extrusion to obtain the high-strength and high-conductivity copper alloy. The high-strength and high-conductivity copper alloy is good in conductivity and mechanical property. The method is simple in process, environmentally friendly, low in cost and suitable for industrial production.

The invention discloses a positive electrode material with a coating layer, a preparation method of the positive electrode material and a lithium ion battery. The positive electrode material with the coating layer comprises a positive electrode inner core and the coating layer coated on the surface of the positive electrode inner core, wherein the chemical composition of the positive electrode inner core is Li [alpha] Ni [x] Co [y] Al [z] A [m] O [2]; the coating layer contains an element Co and an element X, and the mass ratio of the element X in the coating layer to the element Co in the coating layer is 50%-100%; x is a metal element different from Co, and 50 wt.% or more of X is an Al element; the positive electrode core comprises a coating layer, the coating layer comprises a lithium cobalt oxide, the lithium cobalt oxide comprises specific contents of Li Co < 1-a > Co < 2 > O < 4 >, Li Co < 1-b > O and Li < Co > O < 2 >, and by taking the total mass of the positive electrode core as a reference, the content of Co element in the coating layer is 1000-4000 ppm. According to the invention, the positive electrode material can give consideration to both low heat production and gas production.

The invention provides an electron beam selective melting printing TiAl alloy and an Al element loss inhibition method, and relates to the technical field of engine material design and preparation. According to the Al element loss inhibition method, the phase change path and the single-phase region temperature range of the alloy are optimized through reasonable component adjustment, and the Al element loss is inhibited by controlling factors such as bottom plate preheating, current and speed, scanning line arrangement and the like in the preheating stage and factors such as return time, current and speed, scanning line arrangement and the like in the melting stage. And the loss of the Al element in the printing process is effectively controlled. According to the method, the temperature difference between the powder and the molten pool is reduced, and a fine full-lamellar structure with uniform elements and crystal grains is obtained. The structure has good high-temperature performance, and a brand new idea is provided for blade materials and machining. And moreover, room-temperature and high-temperature mechanical properties can be synergistically improved, Al element loss is inhibited, the resource utilization rate is high, the process is short, efficiency is high, and industrial large-scale production and popularization are facilitated.

The invention discloses a preparation method of a multistage strengthened coating on the surface of zirconium alloy, a multilayer film with CrTaNbSiO multi-component oxide layers and CrAlTaNbSi multi-component metal layers distributed alternately is prepared on a Zry-4 substrate through a magnetron sputtering method, and the thickness of each layer is 0.8-1.2 microns. The CrAlTaNbSi layer provides plasticity and toughness buffering through a high-entropy effect; the CrTaNbSiO layer takes amorphous SiO2 as a matrix, and a CrTaO4 / CrNbO4 nanocrystalline phase is embedded, so that the cooperation of oxygen diffusion blocking and nanometer strengthening is realized, and relatively high hardness and wear resistance are provided; the Al element in the multi-component metal layer diffuses into the oxide layer under the specific oxygen partial pressure to form a continuous Al2O3 layer, diffusion of the element is further hindered, the interface self-strengthening effect is achieved, and the coating is prevented from being peeled off.

Disclosed are a MAX-Ag conductive composite coating and a preparation method therefor. The conductive composite coating comprises a MAX phase and an Ag phase. The chemical formula of the MAX phase is Mn+1AXn, where M is a transition metal element, A is an Al element, X is a C or N element, and n is an integer ranging from 1 to 3. The MAX phase is of a strip-shaped structure, and the Ag phase is of a nanotwinned structure. The Ag phase aggregates at the grain boundaries of the MAX phase, and the conductive composite coating is of an Ag-wrapped MAX phase structure as a whole. In the present invention, the MAX phase coating is designed, by means of Ag doping, to have a heterogeneous grain shape. The doped Ag affects the growth of MAX phase grains, so that the MAX phase grains are of the strip-shaped structure. Furthermore, the doped Ag is of the nanotwinned structure, and fully wraps the MAX phase grains. Ag is continuously distributed at the MAX grain boundaries. Such a special structure may effectively reduce the scattering of electrons, provide a strong conductive path, and enable the coating to have excellent conductive properties.

The present invention belongs to the field of new material design, and the alloy provided is Al‑Cu‑Mg‑Ag‑Si‑Sc‑Mn‑Zr, and its composition range is: Cu is 3.8-4.6wt%, Mg is 0.5-1.0wt%, Ag is 0.5-1.0wt%, Si is 0.3-0.5wt%, Sc is 0.05-0.25wt%, Mn is 0.2-0.5wt%, Zr is 0.05-0.15wt%, and the balance is Al element. The basic preparation method of the alloy provided by the present invention is: vacuum induction melting → iron mold casting → homogenization treatment → hot rolling deformation → solution aging. After all the process treatments, the alloy provided by the present invention has high yield strength and tensile strength at room temperature and 210°C, and has high durability at 210°C.

A high-toughness and high-thermal-conductivity die-cast magnesium alloy and a preparation method therefor. The high-toughness and high-thermal-conductivity die-cast magnesium alloy comprises the following components in percentage by weight: Al: 2.5-4.0%, RE: 3.5-5.5%, Mn: 0.1-0.3%, Be: 0.002-0.003%, Ca: 0.1-1.0%, Gd: 0.05-0.3%, Re being one or two of La or Ce, and the balance comprising Mg and other inevitable impurities. The described elements need to simultaneously satisfy: 0.7≤Al / RE≤0.8. Introduction of a new acicular Al3RE second phase enables the mechanical properties of the material to be improved with a better second phase strengthening effect. Formation of the second phase reduces the adverse impact of the Al element on the thermal conductivity of a magnesium alloy, and also inhibits generation of brittle phase Mg17Al12 and prevents the thermal conductivity from being significantly reduced, thereby obtaining a magnesium alloy having both high thermal conductivity and high room-temperature mechanical properties. The obtained magnesium alloy has a room-temperature yield strength of 140-150 MPa, an elongation rate of 8-12%, and a thermal conductivity of 100-110 W / (m·K).

The invention provides an anodic oxidation die-casting aluminum alloy and a preparation method thereof. The anodic oxidation die-casting aluminum alloy comprises the following elements of, by mass, 0.01%-1% of Mg element, 0.01%-2% of Zn element, 0.01%-2% of Si element, 0.01%-1% of Ni element, 0.2%-0.5% of Fe element, 1.6%-2.4% of Mn element, 0.1%-0.2% of Cu element, 0.02%-0.2% of Ti element, the total content of inevitable impurities smaller than or equal to 0.2%, and the balance Al element. Wherein the sum of the mass content of the Mg element and the mass content of the Zn element is 1-3%, the sum of the mass content of the Si element and the mass content of the Ni element is 0.1-2.5%, and the sum of the Fe element, the Si element and the Ni element is 0.1-3%. The aluminum alloy can be better used for producing thin-wall piece products with the thickness of 0.8-1.8 mm.

The invention discloses a preparation method of a TC4 titanium alloy cast ingot. The preparation method comprises the following steps: determining a used residual waste component range according to target components of the TC4 titanium alloy cast ingot; the residual waste materials and the aluminum bars are evenly arranged in a feeding groove of the electron beam cold bed furnace; primary smelting is conducted through an electron beam cold bed furnace, and a primary cast ingot is prepared; and the primary cast ingot is smelted through a vacuum consumable electric arc furnace, and the TC4 titanium alloy cast ingot is prepared. Before material distribution, the loss amount in Al element smelting is calculated, and supplementation is carried out during material distribution, so that excessive loss of the Al element in EB smelting is made up, and the ingot casting quality is improved; the aluminum bars are uniformly distributed in the feeding groove, so that the burning loss of the aluminum element is balanced, the aluminum element in the cast ingot is uniformly distributed, and the phenomenon of macrosegregation is improved.

The invention belongs to the field of selective laser melting rapid prototyping, and discloses a TiCN nanoparticle-containing magnesium alloy for selective laser melting and application thereof, and the TiCN nanoparticle-containing magnesium alloy powder for selective laser melting comprises the following components by mass: 8.5-9.5% of Al element, 0.5-0.9% of Zn element, 0.2-0.4% of Mn element, 1.5-2.5% of TiCN nanoparticles, less than or equal to 0.1% of impurity, and the balance of Mg element. The TiCN nanoparticles are introduced into the magnesium alloy, the selective laser melting process is matched, the mechanical property of the correspondingly obtained SLM magnesium alloy forming part is good, the ductility of the forming part is further improved through the refined and uniform magnesium alloy grain structure and dispersively distributed nano TiCN, and the tensile strength, the yield strength and the creep fracture life of the forming part are all improved.

The invention relates to the field of titanium alloy materials, in particular to an inactive eutectoid element regulated alpha + beta type titanium alloy and a preparation method thereof. The titanium alloy comprises the following chemical components in percentage by mass: 5.0 to 7.0 percent of Al element, 2.0 to 4.0 percent of Nb element, 1.0 to 3.0 percent of Mo element, 1.0 to 3.0 percent of V element, 1.0 to 2.0 percent of Zr element, 0.5 to 3.0 percent of Fe element and the balance of Ti. The preparation process of the titanium alloy comprises the steps of electrode pressing, cast ingot preparation, high-temperature homogenization treatment, forging, rolling, solution treatment and aging treatment. The strength and toughness of the titanium alloy are adjusted by regulating and controlling the content of the non-active strong beta stable element Fe, the alpha + beta type high-strength and high-toughness titanium alloy with different strength levels is obtained, and the alpha + beta type high-strength and high-toughness titanium alloy can be widely applied to the important fields of aerospace, ocean engineering, weaponry, petrochemical engineering, automobile industry, biomedical treatment and the like.

The invention relates to the technical field of anode steel claws, and discloses a method for preparing an anode steel claw alloy material through a powder metallurgy vacuum sintering method, and the method comprises the following steps: S1, adding an Al element and a B element on the basis of a ZG2000-400 formula; and S2, all the element components are mixed and then subjected to compression molding and sintering treatment, and the alloy material is obtained. The anode steel claw alloy material provided by the invention not only meets the basic requirements of ZG200-400, but also is added with two elements of Al and B for microalloying on the basis, and the strength, hardness, corrosion resistance and the like can be improved by utilizing Al and B microalloying.

The invention relates to the technical field of metal material additive manufacturing, in particular to an additive manufacturing TiAl alloy structure homogenization method. According to the method, 1.5 at.%-2.5 at.% of an Al element is added into a TiAl alloy for compensation, then TiAl alloy powder is prepared, electron beam selective melting printing is carried out, short-time circulating heat treatment is carried out after hot isostatic pressing treatment is carried out, the temperature in the short-time circulating heat treatment process is 5-20 DEG C higher than T alpha / (alpha + gamma), and heat preservation is carried out for 3-10 min; according to the method, the problem of non-uniform structure of the TiAl alloy formed by SEBM is synergistically solved by compensating the content of Al element and a short-time circulating heat treatment process, a uniform and fine lamellar structure can be obtained without a complicated process parameter optimization process, the size of a lamellar cluster is smaller than 100 microns and is far lower than that of a lamellar cluster prepared by conventional heat treatment, and the method is suitable for large-scale production. The room-temperature tensile strength of the alloy is at least improved by 150MPa, and the tensile strength at 750 DEG C is at least improved by 80MPa. The process method is simple and high in adaptability, and can be widely applied to additive manufacturing of the TiAl alloy.

The invention discloses a liquid phase growth method of n-type silicon carbide crystals, and belongs to the technical field of semiconductors. By changing the formula of a growth raw material for silicon carbide growth, the growth raw material is configured to be SixCryMz, the molar ratio x of Si to the raw material is 40-70%, the molar ratio y of Cr to the raw material is 20-60%, and the molar ratio z of M to the raw material is 1-10%; m is one or more of Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Ce, La, Tb, Nd, Ta and Pr. According to the method, other elements M are doped on the basis of a Si-Cr system, the liquid growth method is matched to replace an Al element to improve the crystal morphology, meanwhile, evaporation of solution components can be inhibited, and the growth system can be kept stable for a longer time, so that the n-type silicon carbide crystal with more uniform surface steps can be grown.

The invention belongs to the technical field of non-ferrous metal materials, and particularly relates to a high-strength and high-thermal-conductivity magnesium alloy and a preparation method thereof. The high-strength and high-thermal-conductivity magnesium alloy comprises Zn, mischmetal, Al, X elements and the balance Mg and inevitable impurity elements, the X elements are at least one of Sb, Sn and Y. The high-strength and high-thermal-conductivity magnesium alloy is obtained by melting Mg ingots, Al ingots, Zn ingots, mischmetal and Mg-X, refining, deslagging and casting. Alloy elements such as Zn and La / Ce mixed rare earth which have small influence on the thermal conductivity of the magnesium alloy are added into the alloy, the negative influence of the alloy elements on the thermal conductivity is reduced, the casting performance of the alloy is optimized, grains are refined, the mechanical property of the alloy is improved by adding the La / Ce mixed rare earth and the Al element, a large number of second phases are formed at the grain boundary, and the thermal conductivity of the magnesium alloy is improved. And secondly, compared with pinning of the grain boundary, the mechanical property of the alloy is further enhanced.

The invention provides an Er-Zr microalloyed AlSi10Mg alloy powder material, a preparation method of the Er-Zr microalloyed AlSi10Mg alloy powder material, an aluminum alloy workpiece and a preparation method of the aluminum alloy workpiece. The Er-Zr microalloyed AlSi10Mg alloy powder material comprises the following elements in percentage by mass: 9.50 to 10.60 percent of Si element, 0.35 to 0.55 percent of Mg element, 0.70 to 1.30 percent of Er element, 0.70 to 1.30 percent of Zr element, less than or equal to 0.15 percent of total content of inevitable impurities, less than 0.05 percent of single impurity and the balance of Al element. And the Zr element and the Er element can form a dynamically stable L12Al3 (Er, Zr) phase, and the second phase strengthening effect and the recrystallization inhibition effect are achieved, so that the mechanical property of the aluminum alloy workpiece is improved.

The application discloses a gallium oxide vertical device and a preparation method thereof. The gallium oxide vertical device comprises an epitaxial structure, a cathode and an anode matched with the epitaxial structure, the epitaxial structure comprises a heavily doped n-type Ga2O3 substrate, a lightly doped n-type Ga2O3 drift region, an interlayer and a p-type nitride epitaxial layer which are sequentially stacked, the lightly doped n-type Ga2O3 drift region, the interlayer and the p-type nitride epitaxial layer form a p-i-n structure, the cathode forms an ohmic contact with the heavily doped n-type Ga2O3 substrate, and the anode forms an ohmic contact with the p-type nitride epitaxial layer, wherein the material of the interlayer is an Al-containing compound, and the surface layer region of the lightly doped n-type Ga2O3 drift region close to the interlayer also has Al elements, the Al elements are diffused into the lightly doped n-type Ga2O3 drift region in the bonding process under high pressure.

The application discloses a preparation method of a high-strength cast magnesium alloy, the alloy containing two non-rare-earth strengthening alloy elements of Sr and Ti, wherein the Ti element is preferentially combined with Al to form AlTi or Al3Ti intermetallic compounds and is gathered along the grain boundary, hindering the growth of alpha-Mg grains, the remaining Al element is combined with Mg to form a beta phase, the grain size is reduced, the morphology of the beta phase is improved, and thus the mechanical properties are improved; the Sr element can strengthen the beta phase on one hand, and can consume the Al element at the solidification front by forming a new Al4Sr phase, so that the volume fraction of the beta phase is reduced; in addition, the Sr element can form an adsorption film of strontium on the grain growth interface as a surface active element, so that the grain growth speed is reduced, the alloy has more time to generate more crystal nuclei when solidifying, and the grains are refined; under the synergistic effect of the two elements, the strength of the magnesium alloy is significantly improved.

The present invention belongs to the technical field of cemented carbide manufacturing, and discloses a cemented carbide with a cobalt-aluminum intermetallic compound CoAl as a bonding phase and a preparation method thereof. The cemented carbide is composed of a cobalt-aluminum intermetallic compound CoAl as a bonding phase and a hard phase WC. When the molar ratio of the added Co element and the Al element is 1:1 or 3:2, respectively, a cemented carbide with the intermetallic compound CoAl as a bonding phase is obtained. The mixed powder is evenly mixed by ball milling, and then spark plasma sintering is performed to finally obtain a dense cemented carbide with the cobalt-aluminum intermetallic compound CoAl as a bonding phase. The material composition of the present invention is reasonably designed, the preparation process is simple and controllable, the production cost is low, and large-scale industrial production and application are possible.