38results about How to "Control interface response" patented technology

The invention discloses a low temperature glass phase enhanced SiCp / Cu composite material and a preparation method thereof, and belongs to the technical field of ceramic enhanced metal-based composite material preparation. SiC particles coated by a glass phase are dispersed in Cu matrix of the SiCp / Cu composite material; and the glass phase comprises SiO2 and K2O, wherein a molar ratio of SiO2 to K2O is 2-6 and a volume ratio of SiC to SiO2 and Cu in the glass phase is 1:(0.2-1.2):(2-4). On one hand, the low temperature glass phase has good interface wettability with the SiC particles in melting, a certain amount of Cu2O is formed on the Cu-based particle surfaces during a sintering process of the composite material, and Cu2O participates in formation of interface glass phase, so that the Cu matrix has good adhesion with the glass phase. On the other hand, the introduction of the interface glass phase can prevent direct surface contact of a plurality of SiC particles in aggregation and prevent mutual diffusion of reactant atoms in an interface solid-phase reaction, thereby effectively inhibiting formation of interface solid-phase reaction products and enabling the composite material to gain excellent comprehensive mechanical properties.

The present invention relates to one kind of gradient Ti / Al2O3 composite material for the intermediate layer of wave impedance flying plate. The gradient composite material is produced through the steps of mixing material, pressure forming, setting the gradient material inside graphite mold and fast plasma discharge sintering. The material contains Ti in 45-69 wt%, alpha-Al2O3 in 30-50 wt%, and Nb in 0.5-5 wt%. In the gradient material, Ti content is decreased gradiently from maximum value to zero, alpha-Al2O3 content is increased from zero to maximum, and Nb content is decreased, with the Ni content in both the top and bottom layers being zero. The composite material of the present invention has tightly combined interface, integral structure, high compactness, wave impedance distribution index of 2-3, capacity of obtaining good quasi-isoentropic compression waveform, excellent weldability and other advantages.

The invention provides a method for laser wire-filling welding of medium-thick aluminum / steel dissimilar metals, which comprises the following steps: (1) making Y-shaped grooves and V-shaped grooves respectively on aluminum plates and steel plates of equal thickness to be welded, and Deep cleaning of the Y-shaped groove, V-shaped groove, and the upper and lower surfaces of the aluminum plate and steel plate; (2) Place the aluminum plate and steel plate to be welded on the welding fixture for clamping and fixing, and the welding joint form is a butt joint; (3) Adjust The position of the main beam and the auxiliary beam, setting the beam power; (4) setting the process parameters, and once the welding process parameters are determined, they will remain unchanged during the welding process. The welding method uses laser wire filling to increase the absorption rate of the aluminum alloy, stabilize the welding process, prevent the conditions for crack formation, and improve the mechanical properties of the weld, and the welding method can effectively adjust the temperature field distribution of the welded joint, which is beneficial to control Interfacial reaction, while solving the defect of unfused sidewall, improving the strength of welded joints.

The invention provides a low-cost rare-earth-free nanocomposite permanent-magnetic material and a preparation method thereof. A chemical formula of the low-cost rare-earth-free nanocomposite permanent-magnetic material is Mn<53-x>Al<45>C<2>W<x> / (Fe<l-y>Co<y>)<2>B. The preparation method comprises the steps of: burdening a pure metal raw material according to the name of an Mn<53-x>Al<45>C<2>W<x> alloy to obtain a master alloy ingot and fabricating a thin strip; carrying out vacuum heat treatment on a quick quenched strip to obtain a tau-phase Mn<53-x>Al<45>C<2>W<x> alloy; carrying out burdening according to (Fe<l-y>Co<y>)<2>B alloy ingredients to obtain the master alloy ingot and fabricating the thin strip; carrying out high-energy ball-milling on the quick quenched strip of the Mn<53-x>Al<45>C<2>W<x> alloy and the quick quenched strip of the (Fe<l-y>Co<y>)<2>B alloy which are subjected to heat treatment to prepare nanocrystalline alloy powder; carrying out spark plasma sintering on the obtained nanocomposite powder to obtain a full-dense nanocomposite permanent-magnetic material; and carrying out thermal deformation on the sintered nanocomposite permanent-magnetic material, improving the degree of orientation and obtaining the low-cost rare-earth-free anisotropic nanocomposite permanent-magnetic material. The prepared permanent-magnetic material does not contain a rare-earth element; the raw material cost is effectively reduced; and meanwhile, the technology is simple, easy to operate and suitable for large-scale mass production.

A method for preparing a ferric oxide ceramic thin film on the surface of three-dimensional network silicon carbide belongs to the material technical field, and comprises the following steps: (1) a sol-gel method is adopted for preparing iron sol; (2) a vacuum impregnation method is adopted for coating on 3D-SiC; and (3) the three-dimensional network silicon carbide coated by the iron sol is sintered. The invention uses the low-cost raw material, the simple preparation method and the short preparation period to prepare the uniform and compact ferric oxide ceramic thin film with low porosity onthe 3D-SiC matrix surface; the thin film has stronger bonding strength with the matrix and has excellent thermal shock resistance, thus realizing to control the interface reaction of the 3D-SiC / steel.

The invention provides a preparation method of a high-coercive-force and high-stability neodymium iron boron magnet. The preparation method comprises the following steps: preparing materials according to components of a NdFeB alloy to obtain a master alloy ingot and rapidly quenching to prepare a thin strip; preparing the rapidly-quenched thin strip into nano-crystal alloy powder; weighing and preparing materials according to an alloy nominal composition Sm2Fe17; carrying out high-energy ball milling to obtain nano-crystal alloy powder; carrying out nitriding treatment on the Sm2Fe17 nano-crystal alloy powder in high-purity N2 gas or NH3 gas to obtain Sm2Fe17Nx nano-crystal alloy powder; mixing the NdFeB and the Sm2Fe17Nx nano-crystal alloy powder at a ratio to obtain compound powder which is uniformly mixed; carrying out magnetic field orientation on the compound powder and press-molding to form a blank; and carrying out spark plasma sintering on the blank to prepare a NdFeB / Sm2Fe17Nx magnet. With the adoption of the preparation method of the high-coercive-force and high-stability neodymium iron boron magnet, the use amount of rare earth is reduced and the cost is relatively low; and high-temperature-resisting neodymium iron boron magnet can be prepared through the preparation method, so that the market requirements are met.

The invention relates to a preparation method of a high-electromagnetic-shielding hollow micro-sphere enhanced AZ91 magnesium matrix composite and relates to a preparation method of a hollow micro-sphere enhanced AZ91 magnesium matrix composite. The preparation method is used for solving the problems that structures of hollow micro-spheres are seriously damaged in the preparation process of an existing composite material. The method comprises the following steps: firstly, adding water into quick lime to react, aging, and calculating the weight of Ca(OH)2 and water in a Ca(OH)2 solution; secondly, adding the hollow micro-spheres and water to obtain a mixed solution, cleaning the hollow micro-spheres after reaction, and drying to obtain surface-coated hollow micro-sphere particles; thirdly, melting an AZ91 magnesium alloy, removing surface oxide scales, cooling, preserving heat, adding the hollow micro-sphere particles, stirring, rising temperature, and molding to obtain the magnesium matrix composite of which the hollow micro-sphere surface appearance is relatively complete. According to the prepared composite disclosed by the invention, the appearance of the hollow micro-spheres in the composite is kept relatively well, and the electromagnetic shielding effectiveness reaches 79-82dB. The preparation method disclosed by the invention is used for preparing the magnesium matrix composite.

The invention discloses a method for coating a surface of reinforcement in a composite material, and relates to a method for coating a surface of reinforcement. The method can be used for solving the problems of coated tissue non-uniformity, poor compactness and coverage incompleteness in the conventional method for coating the surface of the reinforcement. The method comprises the following steps: 1, mixing reinforcement with metal powder, and obtaining mixed powder after ultrasonic cleaning; 2, pouring the mixed powder into distilled water or a salt solution, heating, coating, and then taking out the reinforcement; and 3, sintering the reinforcement. According to the method for coating the surface of the reinforcement in the composite material, a netlike structural coating is uniformly covered on the surface of the coated reinforcement, and the coating has small and compact tissues; and in the later composite material preparation process, the wetting property between the reinforcement and a substrate is greatly promoted, and the interface reaction between the reinforcement and the substrate is effectively controlled. By utilizing the method for coating the surface of the reinforcement in the composite material, the surface state of the reinforcement can be preferably regulated, and a technical guarantee is provided for the later prepared composite material to achieve excellent mechanical property.

The invention provides a method for preparing a titanium aluminum compound base composite material, which is characterized by comprising: firstly, alternatively depositing a simple substance layer Ti and a simple substance layer Al on the external surface of SiC fiber; and secondly, performing pressing by adopting vacuum heat pressing or hot isostatic pressing at a certain temperature, and forming a composite material by diffusion bonding. The method effectively reduces the preparation temperature of the Ti-Al compound base composite material, remarkably reduces the thermal stress crack caused by the difference between the coefficients of thermal expansion in the process of cooling a basal body, and ensures that the interface reaction between the basal body and the fiber is controlled well. The method has great expected economical values and social values.

The invention discloses a method for modifying a high-wettability coating on the surface of a metal-based compound material reinforcement. The method comprises the following steps of: 1, by a common coating preparation method, forming a metal oxide coating, of which reducibility is lower than that of magnesium, on the surface of the reinforcement; 2, and placing the reinforcement coated with the metal oxide coating and pure magnesium in a vacuum furnace in a way of placing the pure magnesium on the bottom of the furnace and placing the reinforcement above the pure magnesium, vacuum-pumping the furnace, keeping the vacuum degree below 10Pa, heating the furnace to 600 to700 DEG C, and keeping the temperature for 5 to 60 minutes so as to allow the magnesium steam and the metal oxide coating on the surface of the reinforcement to undergo an oxidation-reduction reaction to generate a compound layer formed by an inner layer made of compounds and an outer layer made of reduced metal. The method has the advantages of simple and controllable process, low equipment requirements, low cost, wide application range, high mechanical and physical properties and the like.

The invention discloses an ultrasonic-assisted laser spot welding device and method. The device comprises: a laser welding head, a C-shaped frame, a six-axis linkage robot, a laser, an ultrasonic vibration device and a pneumatic transmission system; the laser welding head is installed on a six-axis On the linkage robot, it is connected with the laser; the C-shaped frame is installed under the laser welding head, and the upper end of the C-shaped frame is provided with an opening. The laser emitted by the laser welding head can pass through the opening and irradiate the metal material to be welded below the opening; The pneumatic transmission system is fixed on the lower end of the C-shaped frame, and the ultrasonic vibration device is installed on the pneumatic transmission system. The invention introduces high-frequency ultrasonic energy into welding, effectively controls interface reaction and strengthens melt flow, improves interface wettability, refines weld grains, and subsequent ultrasonic vibration is more helpful to reduce or eliminate weld and The residual stress of the connection surface improves the connection strength.