72results about How to "Hinder dislocation movement" patented technology

The invention discloses a method for regenerating a dental prosthetic material and an acidic amino acid-induced demineralized dental enamel outer enamel prism thereof in situ, and belongs to the technical field of in-situ regeneration of dental enamel outer enamel prisms. The preparation method is as follows: firstly, carrying out surface calcium activation onto a dental enamel surface, i.e., grafting calcium ions; then, forming calcium carbonate stable calcium ions step by step; finally, taking calcium carbonate stable calcium ions as foundation forms to synthesize hydroxyapatite crystals. Amino acid participates in the whole process, concentration of the amino acid added in a two-step process is consistent. The hydroxyapatite crystals deposited on the surface of the demineralized dental enamel are orderly and compact in sequence, and uniform in crystal morphology, so that obvious continued growth tendency of an artificial layer can be seen. The preparation method disclosed by the invention lowers protein extracting cost and harsh restrictions on an application environment, and is wide in prospect. The material prepared by the method disclosed by the invention can be applied to cosmetic dental for filling demineralization gaps, also can be used for repairing early-stage enamel demineralization, and can be used as a combined material for bottom pulp capping pit and fissure sealing, and the like.

The invention discloses high-strength and high-toughness cast magnesium alloy. The high-strength and high-toughness cast magnesium alloy is Mg-Bi-Ca-Zn alloy and composed of, by weight, 3.0-8.0% of Bi, 0.1-1.2% of Ca, 0.1-2.0% of Zn and the balance Mg. According to the invention, Bi serves as the main alloy element, lots of Mg3Bi2 phases are formed through the simple alloying way, few Ca elements and Zn elements are adopted for improving the strength of the alloy, the Ca elements effectively improve the morphology and distribution of the Mg3Bi2 phases so as to improve the plasticity of the alloy, and therefore the high-strength and high-toughness cast magnesium alloy can be developed for the Mg-Bi alloy series. The cast magnesium alloy is high in strength and plasticity, the tensile strength of the alloy with the components optimized reaches about 270 MPa, the yield strength of the alloy reaches about 145 MPa, and the ductility of the alloy reaches about 10%. Thus, the strength can be as high as that of rare earth magnesium alloy, and the ductility is high.

The invention provides a heat treatment method of a GH 4780 alloy forging, and relates to the technical field of alloy manufacturing. The method comprises the following step: carrying out solution heat treatment on the GH 4780 alloy forging, wherein the temperature of the solution heat treatment is 1020-1170 DEG C. The GH 4780 alloy forging subjected to heat treatment not only can effectively eliminate the segregation of alloy elements such as Ti, Al and Cr in the smelting process and eliminate metallurgical defects such as cavities, but also can break columnar crystals and promote dynamic recrystallization, thereby refining the crystal grains and improving the strength and plasticity of the alloy forging.

The invention provides a high-strength deformation magnesium alloy containing rare earth samarium, and a preparation method thereof, belongs to the technical field of metal materials, and solves the problem of overhigh rare earth content and poor mechanical property of traditional magnesium alloy. The magnesium alloy disclosed by the invention is prepared from the following ingredients in parts byweight: 1.0-6.6wt% of Sm, 0.5-3.5wt% of Zn, 0.15-1.5wt% of Zr and the balance of Mg. The invention also provides a preparation method for the high-strength deformation magnesium alloy containing rareearth samarium. The high-strength deformation magnesium alloy containing rare earth samarium disclosed by the invention has excellent mechanical property. Mg-3.5Sm-0.6Zn-0.5Zr is taken as an exampleto show that the indoor temperature yield strength and the tensile strength are respectively 415MPa and 423MPa.

The invention provides a method for improving Mg-Al-Zn magnesium alloy thermoforming and service performance. The method comprises the steps that Mg-Al-Zn magnesium alloy is subjected to pre-deformation treatment at 25 DEG C to 300 DEG C, twin crystal or low-angle crystal boundaries are introduced, and then aging treatment is conducted. According to the deformation heat treatment method, precipitation of a continuous precipitation phase of the Mg-Al-Zn magnesium alloy can be effectively promoted, and alloy tissue with a uniform, small and dispersively distributed precipitation phase is obtained finally; and alloy strength and plasticity are synchronously improved, and thermoforming performance and service performance of the alloy are improved. The method for improving the Mg-Al-Zn magnesium alloy thermoforming and service performance is reasonable in design, simple in equipment requirement, convenient to operate, low in cost and high in efficiency, distribution of the precipitation phase of the Mg-Al-Zn magnesium alloy is reasonably controlled, the thermoforming performance and service performance of the alloy are improved, and the method has a good industrial application prospect.

The invention relates to a preparation method of an intermetallic compound Al3-M particle reinforced aluminum matrix composite and belongs to the technical field of aluminum matrix composite preparation and metal smelting. The invention aims at providing the preparation method of the intermetallic compound Al3-M particle reinforced aluminum matrix composite, and provides the intermetallic compound Al3-M particle reinforced aluminum matrix composite prepared by the method at the same time. The invention adopts the technical scheme that the preparation method of the intermetallic compound Al3-M particle reinforced aluminum matrix composite well solves the problem of no infiltration between an intermetallic compound reinforced particle and molten metal by a stepped method of firstly increasing the magnesium concentration in aluminum melt and adding the intermetallic compound particle.

The invention provides a high-strength titanium alloy and a preparation method thereof. The high-strength titanium alloy comprises, by mass, 4.5%-5.5% of Al, 3.5%-4.5% of Mo, 3.5%-4.5% of Cr, 1.5%-2.5% of Sn, 10%-50% of Zr and the balance Ti. According to the high-strength titanium alloy and the preparation method thereof, the content of all the elements is strictly controlled, and the mechanicalproperty of the titanium alloy is improved; the Cr element is added, therefore, a beta phase is stabilized, and the room-temperature strength of a titanium alloy matrix can be significantly improved;the Al element greatly improves the stability of an alpha phase and increases the beta-alpha conversion temperature, the uniform and fine alpha phase can be conveniently obtained after quenching in the solution treatment process, and the specific strength of the titanium alloy can be significantly improved; and in addition, lattice distortion can be caused due to addition of the Zr element, the defects can cause nucleation point increasing and nucleation density increasing in the nucleation process, the grain refinement effect is achieved, and then fine crystal strengthening is achieved.

The invention provides a high-strength wrought aluminum alloy containing rare earth samarium and a preparation method of the high-strength wrought aluminum alloy, and belongs to the technical field ofmetal materials. The problem that an existing aluminum alloy is poor in mechanical property is solved. The aluminum alloy is prepared from the following chemical components of, in percentage by mass,1.5wt.% - 2.5wt.% of Mg, 0.5wt.% - 1.5wt.% of Si, 0.2wt.% - 1.2wt.% of Cu, 0.1wt.% - 0.5wt.% of Sm and the balance Al. The high-strength wrought aluminum alloy containing the rare earth samarium hasexcellent mechanical properties, and by taking Al-2Mg-Si-0.9Cu-0.5Sm as an example, the room-temperature yield strength and the tensile strength of the Al-2Mg-Si-0.9Cu-0.5Sm is 315MPa and 423MPa respectively.

The invention provides a low-density high-strength magnesium-lithium alloy and a preparation method thereof. The components and mass percentages of the magnesium-lithium alloy are: 11-15% Li, 0.5-4% Al, 0.05-0.5% Zr, 0.2~1.2%La, 0.1~0.6%Ce, the total amount of impurity elements Fe, Ni, Cu, Si≤0.2%, and the balance is Mg. The preparation method of the magnesium-lithium alloy involved in the present invention includes vacuum induction melting and plastic deformation treatment. The magnesium-lithium alloy processed by means of alloying, crystal grain refinement and deformation treatment in the present invention has high strength and plasticity under the premise of ensuring low density, and at the same time has excellent machining performance.

The invention discloses a high-performance arc spraying Zn-Al powder core wire and a preparation method thereof, belonging to the technical field of metal surface protection. The wire is mainly composed of an outer cladding and a powder core, wherein the outer cladding is a Zn-Al alloy strip; the powder core is mainly composed of the following components in percentage by weight: 60-70% of nano Al2O3 powder, 10-20% of nano TiO2 powder and the balance of nano Y2O3 powder; and the nano powder core accounts for 5-20% of the total weight of the wire. The novel Zn-Al nano powder core wire can be prepared into a Zn-Al nano composite coating through an arc spraying method; and the ocean climate corrosion resistance and the hardness of the coating are far higher than those of the common arc spraying Zn-Al coating.

The invention discloses a copper-based aerogel enhanced copper alloy and a preparation method thereof, and belongs to the technical field of metal materials and preparation thereof. The copper-based aerogel reinforced copper alloy comprises, by mass, 0.5%-10% of zinc, 2%-8% of silicon dioxide and the balance copper. The preparation method comprises the following steps of burdening, ball milling, material mixing, cold pressing forming, pressure sintering and finished products. According to the copper-based aerogel enhanced copper alloy, the tensile strength of the prepared copper-based composite material is higher than 300 MPa, the yield strength is equivalent to that of a common copper-based aluminum oxide composite material, the wear rate is lower than 1*10<-9>cm<3>.J<-1>, the heat resistance coefficient is higher than 35000, and the heat resistance and the wear resistance can be better than those of the copper-based aluminum oxide composite material, so that the wear-resistant part made of the material can meet the requirements of long-term normal operation of products or equipment under the condition of high temperature.

The invention relates to the field of powder metallurgy, in particular to a preparation method of a high-temperature-softening-resistant high-strength high-conductivity copper-based composite material molded part, which comprises the steps of precursor powder preparation, nano molybdenum carbide-copper composite powder preparation, green body forming and combined densification. Nano molybdenum carbide particle reinforced copper-based composite powder is prepared through a co-precipitation-co-reduction-selective carbonization process, a composite material blank is prepared through a cold isostatic pressing forming process, and a copper-based composite material forming part with high strength, high conductivity, high wear resistance and high softening temperature is obtained after high-temperature sintering and deformation machining combined densification. The nanoscale molybdenum carbide particles in the copper-based composite material are stable at high temperature, can hinder dislocation movement at room temperature and high temperature, are remarkable in dispersion strengthening effect, have small influences on the electric conduction and heat conduction performance of the material and are excellent in comprehensive performance, and the copper-based composite material has important application prospects in the fields of heat dissipation grooves, electric resistance welding electrodes, nuclear reactor high-temperature-resistant high-heat-conduction components and the like.

The invention provides a method for increasing copper tensile strength. The method comprises the step of performing torsion and plastic deformation on copper. According to the method disclosed by the invention, the copper is performed with the torsion and plastic deformation, so that the copper tensile strength can be increased by forming high-density nanoscale laminated dislocation interface structures in a graded distribution manner inside the copper; in addition, the shear rate, the deformation temperature and the deformation amount of the torsion treatment can be limited, the spaces among the laminated dislocation interfaces can be further fined, and the copper tensile strength can be increased.

The invention belongs to the related technical field of laser additive manufacturing, and discloses aluminum alloy mixed powder, and a method and product for improving the density of an aluminum alloy product. The mixed powder comprises aluminum alloy powder and transition element carbide ceramic powder, wherein the aluminum alloy powder serves as matrix powder, and the mass fraction of the transition element carbide ceramic powder in the mixed powder does not exceed 10%. The mixed powder is used for laser additive manufacturing; when the mixed powder is molten by laser, the aluminum alloy powder and the transition element carbide ceramic powder are metallurgically bonded, and due to the difference of melting points, the aluminum alloy powder is molten while the transition element carbide ceramic powder is not molten; and thus, the transition element carbide ceramic powder forms similar pinning in the aluminum alloy powder, and strengthening of the aluminum alloy matrix powder is achieved. By means of the mixed powder, the mechanical property of the aluminum alloy product is improved, pores are reduced, and the density is improved.

The invention discloses a method for preparing an Al-Mg3Sb2 composite coating on the surface of magnesium alloy. After being mixed, Mg powder and Sb powder are ball-milled in a ball milling machine, so that Mg chemically reacts with Sb to form an Mg3Sb2 intermetallic compound, Mg3Sb2 powder and granulated Al powder are thermally sprayed to the surface of a magnesium alloy workpiece subjected to sandblasting treatment, and the Al-Mg3Sb2 composite coating is obtained; after the Al-Mg3Sb2 composite coating is heated, the coating is hot-pressed on a press machine. The Mg powder and the Sb powder have a solid-phase reaction in the ball milling process to generate the Mg3Sb2 intermetallic compound, Mg3Sb2 melting point is high, heat stability is good, dislocation movement can be effectively hindered, a substrate and a grain boundary are remarkably reinforced, and high-temperature mechanical properties and creep resistance of the workpiece are improved. Pores and layered structures in the thermally sprayed Al-Mg3Sb2 composite coating disappear in the hot press process because the composite coating plastically deforms and is compacted, compactness of the coating is remarkably improved, and the high-temperature mechanical properties and creep resistance are given full play to.

The invention discloses a high-strength anti-fatigue aluminum alloy and a preparation method thereof. The alloy is prepared from, by mass percent, 3.6%-4.1% of Cu, 0.6%-1.1% of Mg, 0.57%-0.69% of Mn,0.35%-0.72% of Ti+La, 0.15%-0.31% of Ni, 0.41%-0.53% of Fe, 0.11%-0.27% of Si, 0.04%-0.13% of Zr, 0.12%-0.26% of Ce, 0.1%-0.18% of W, 0.12%-0.19% of Y, 0.32%-0.46% of Ge, 0.03%-0.12% of Sn, 0.16%-0.29% of Pr+Nd+Er, 0.05%-0.09% of V and the balance Al. The preparation of the aluminum alloy is simple in process, and the obtained aluminum alloy is high in strength, good in toughness and excellent inheat stability and fatigue resistance.

The invention discloses improved low-silver Sn-Ag-Au solder for microelectronic packaging and a preparation method thereof. The solder comprises the following components of, by mass of 0.3%-1.0% of Ag, 0.5%-1.0% of Cu, 0.05%-0.5% of Nb and 97.5%-99.07% of Sn. The solder alloy has the advantage that the Nb element is added in trace on the premise of maintaining the good anti-drop performance of thelower-silver Sn-Ag-Cu solder alloy, so that dislocation movement is hindered, the normal temperature mechanical property of the solder is improved, and the creep resistance is greatly improved; an Zrelement is added, so that the synergistic effect of the Zr element and the Nb element can be achieved, further dispersed distribution of the Nb is promoted, meanwhile, the alloy structure is refined,and the strength and the hardness of the solder are improved; and the liquidity of liquid solder can be improved by addition of a rare earth element Yb, the wettability can be improved, and the creepresistance of brazing filler metal can be improved.

The invention belongs to the technical field of heat treatment of aluminum alloys, and specifically relates to an aging heat treatment method for a high-zinc aluminum alloy containing scandium. The method comprises the following steps: firstly, preserving heat for the high-zinc aluminum alloy containing scandium for 3.5-4.5h at the temperature of 455-465 DEG C, then, 10s later after heat preservation, transferring the high-zinc aluminum alloy containing scandium into water at room temperature for quenching for 5min, and further carrying out two-stage aging heat treatment: preserving heat for 5.5-6.5h at 100-120 DEG C, then, heating up to 155-175 DEG C in furnace and preserving heat for 6-8h, finally cooling to room temperature, and thereby obtaining the high-zinc aluminum alloy containing scandium subjected to aging heat treatment. With the method provided by the invention, hardness, tensile strength, yield strength and elongation of alloy are all improved remarkably, and application range of the high-zinc aluminum alloy containing scandium in the industrial circle is extended.

The invention discloses a nitrogen-vanadium-titanium-niobium rare earth microalloyed high-strength deep-drawing cold-rolled steel plate and a production method thereof. According to the invention, microalloyed elements are fully utilized to be combined with residual interstitial atoms carbon and nitrogen in steel and added trace nitrogen atoms to generate different types of carbonitrides; the solid solubility of free interstitial atoms carbon and nitrogen in the steel is reduced to the minimum, a very small amount of solid solution rare earth elements is guaranteed, formation of {111}//ND texture is promoted, and the r value and the n value of the cold-rolled steel sheet are greatly increased; under the action of factors such as temperature, deformation and cooling rate, the sizes and distribution of different types of carbonitride precipitates are controlled, thicker micron-sized precipitates are beneficial to formation of {111}//ND textures, and dispersed and uniformly distributed nanoscale vanadium carbonitride, titanium carbonitride, niobium carbonitride and rare earth carbonitride hinder dislocation movement, so that the strength of the steel is improved; and under the condition of ensuring proper coarsening of the crystal grains, formation of cake-shaped crystal grains is promoted, and the deep drawing performance is greatly improved.