15 results about "Equal channel angular extrusion" patented technology

The invention discloses a graphene reinforced copper alloy bar and a preparation method thereof, and belongs to the technical field of copper alloys. The preparation method comprises the following steps: preparing a Cu-C master alloy bar; the first copper strip penetrates through a graphite box body, the surface of the first copper strip is covered with a layer of graphene, and the graphene on the surface layer is thinned and evenly coated through a polishing wheel; the treated first copper strip is wound on a Cu-C master alloy rod, sealing welding is conducted on the side face, the two ends are sealed and covered with copper materials, and a first copper roll is obtained; and the copper roll is subjected to equal-channel angular extrusion treatment, repeated extrusion and drawing are conducted, and the graphene reinforced copper alloy bar is obtained. According to the preparation method of the graphene reinforced copper alloy bar, graphene copper (Cu-C mother alloy) is put into a core part of a copper strip coil coated with graphene, then vacuum seal welding is carried out, equal-channel angular extrusion is utilized, so that the graphene can be uniformly distributed, the process is simplified, the efficiency is improved, and rapid mass production is realized at low cost.

The application discloses a preparation process of superplastic magnesium alloy, which comprises the following steps: magnesium alloy waste is treated by low-temperature ball milling to prepare nanoscale powder, the low-temperature ball milling temperature is less than or equal to 200 DEG C, the powder particle size after ball milling is less than or equal to 100 nm, and argon gas is introduced to protect the ball milling process to inhibit oxidation; the nanoscale powder is mixed with 5-8% mass ratio of Mg-Zn-Ca alloy powder, densification is carried out by adopting spark plasma sintering (SPS) at 350-400 DEG C, the sintering pressure is 20 MPa, the holding time is 10 min, and the density after sintering is greater than or equal to 98%; the sintered blank is subjected to equal channel angular pressing (ECAP) treatment, the extrusion temperature is 300 DEG C, the extrusion pass is 4 times, the mold channel included angle is 90 DEG, and the superfine-grained magnesium alloy with an average grain size of 2.1 mu m is obtained; the application realizes grain superfine of 1.5-2.1 mu m through a multi-field coupling process, activates a non-basal slip system at room temperature, the strain rate sensitivity index m is greater than or equal to 0.35, the elongation at 250 DEG C reaches 280%, and the superplastic magnesium alloy has high strength and superplastic deformation capacity.

A method for manufacturing an equiaxed crystal target material, comprising the following steps: a metal bar is made into a forged base material by a radial forging process; the forged base material is made into a first plate material by a rolling process and a plate forging process, the rolling process is rolling along the axial direction of the forged base material; a second plate material is obtained by reciprocating an equal channel angular extrusion process on the first plate material with an equal channel angular extrusion die, the cumulative average equivalent strain of the second plate material is greater than 10, wherein the feeding direction of the first plate material into each equal channel angular extrusion die is the same as the rolling direction of the forged base material; and an annealing and recrystallization heat treatment process is performed on the second plate material to obtain an equiaxed crystal target material. Through the above steps, an equiaxed crystal target material with a grain size of not greater than 20 μm can be obtained for use in the semiconductor industry.

The invention discloses a preparation method of a high-strength and high-conductivity lamellar heterogeneous copper-chromium-zirconium alloy, and belongs to the technical field of preparation and modification of copper alloy materials. According to the method, equal channel angular pressing (ECAP) and an accumulative ply rolling process are combined, CuCrZr alloy subjected to solid solution state and different passes of ECAP treatment is sliced, overlaid, fixed and subjected to one-time ply rolling, metallurgical bonding of the two layers of alloy is achieved, the steps are repeated on metal sheets subjected to ply rolling, accumulative ply rolling can be carried out multiple times, and finally annealing treatment is carried out again. According to the process, an ideal lamellar heterogeneous structure with alternate coarse and fine crystals can be obtained by controlling the size of crystal grains in each layer of alloy, meanwhile, the deformation far larger than that of common rolling can be obtained through multi-pass accumulative ply rolling, the crystal grains are refined to the nanoscale, meanwhile, the influence of a high-density crystal boundary on the electric conductivity is balanced, the tensile strength and the electric conductivity are synchronously improved, and the service life of the alloy is prolonged. The deformation aging process is far beyond the conventional deformation aging process.

The invention provides a high-entropy alloy composite material with a gradient structure and a three-dimensional interpenetrating network reinforced phase as well as a preparation method and application of the high-entropy alloy composite material, and belongs to the technical field of high-entropy alloy preparation. According to the method, entropy alloy matrix powder and functional ceramic reinforced particles are compounded through magnetic field assisted ball milling; directionally arranging the reinforced particles in a mold through a magnetic field-stress synergistic effect to form a cold-pressed preformed blank; implementing multidirectional asynchronous thermal deformation and pulse current auxiliary recovery; double laser beams and a three-dimensional ultrasonic field are adopted for cooperation for selective remelting and gradient regulation and control; densification is carried out in a double-temperature-zone gradient field through reactive infiltration, and a three-dimensional interpenetrating network structure is formed; gradient temperature field hot extrusion and rotation path equal channel angular extrusion are carried out. The high-entropy alloy composite material prepared by the method has a multi-scale gradient structure, shows high strength, high plasticity and excellent high-temperature oxidation resistance and fatigue performance, and is suitable for aero-engine turbine blades, nuclear reactor cladding materials and spacecraft thermal protection systems.

The invention discloses a preparation method of a thermal bimetal strip, which specifically comprises the following steps: step 1, a copper strip or an aluminum bar sequentially penetrates through a sliding sleeve and a sleeve on a base, and then a liquid pump pumps a pickling solution and pure water in a liquid tank into an inner cavity through a liquid conveying pipe; the water flows into the sliding sleeve through the overflow hole to be in contact with the surface of the copper strip or the aluminum bar, so that the oxidation film on the surface of the copper strip or the aluminum bar is removed and rinsed; secondly, the cleaned copper strip or aluminum bar enters a sleeve, and through movement of an arc block and a sliding block, the technical field of metal composite materials is achieved, and the problem that when an existing copper-aluminum bimetal composite material is prepared, due to the fact that dense oxidation films exist on the surfaces of pure copper and aluminum materials, the pure copper and the aluminum materials are subjected to continuous equal-channel angular extrusion after coating is solved; and due to large differences of plasticity, hardness and deformation behaviors, cracking or stripping is easily generated at an interface, so that the forming quality and the mechanical property of the composite material are influenced.

The invention relates to the technical field of magnesium alloy large-size cast ingot preparation, in particular to a large-size rare earth magnesium alloy cast ingot hot crack defect synergistic inhibition method which comprises the following steps: S1, intermediate alloy pretreatment: placing an Mg-30Zr intermediate alloy blank in an equal-channel angular extrusion die, applying 70%-80% of deformation, and carrying out equal-channel angular extrusion on the Mg-30Zr intermediate alloy blank; the Zr clusters with the original size larger than or equal to 762 micrometers are crushed into discrete particles with the particle size ranging from 1 micrometer to 5 micrometers; s2, smelting and modification treatment: preparing materials according to a target alloy ZK61, and smelting industrial pure Mg and Zn and the Mg-30Zr intermediate alloy pretreated in the step S1 under a protective atmosphere; through electromagnetic oscillation and forced convection, the melt convection speed is increased, center melt heat dissipation is accelerated, temperature field / solute field homogenization is achieved, the structure component consistency is improved, casting stress generated in the solidification process is reduced, the generated axial circulation speed exceeds the rare earth sedimentation speed, and the bottom sedimentation phenomenon is effectively restrained; and the distribution uniformity and the yield of the rare earth are improved.

The invention discloses a reciprocating T-shaped variable channel angular extrusion semi-solid rheoforming aluminum alloy and an integrated forming method, and belongs to the technical field of metal material machining. According to the method, the semi-solid rheoforming technology and the reciprocating type T-shaped variable channel angular extrusion technology are integrated, and slurry preparation, structure modification and part forming are continuously completed in the same die system. The core of the die is that the die is provided with a T-shaped channel and three extrusion barrels which are communicated with the T-shaped channel and have larger sections, pressure is alternately applied through a punch, so that semi-solid slurry flows between the extrusion barrels and the channel in a reciprocating mode and is sequentially subjected to forward extrusion densification and equal-channel angular extrusion shearing refinement, grains are ultra-refined to be micron, and casting defects are eliminated. And finally, directly pressing and forming by replacing the cavity die. The method solves the problem that the structure and the shape of a traditional process are difficult to consider at the same time, achieves near-net-shape, high-efficiency and low-energy-consumption integrated manufacturing of high-performance complex parts, and is particularly suitable for production of high-performance aluminum alloy parts in the fields of aerospace, new energy automobiles and the like.

The invention discloses a semi-solid metal slurry preparation method based on equal channel angular pressing, and belongs to the technical field of metal semi-solid forming. The method comprises the following steps: (1) carrying out homogenizing annealing treatment on a metal as-cast blank to obtain an annealed blank; (2) cutting a bar, putting the bar into an equal channel angular extrusion die channel, and carrying out graded speed regulation equal channel angular extrusion on the bar; (3) rotating the extruded blank by taking the axis of the blank as a rotating shaft, and repeating the step of graded speed regulation equal channel angular extrusion until the total rotating angle of the blank reaches 360 degrees, so as to obtain a deformed blank; and (4) the deformed blank is subjected to semi-solid isothermal treatment, and semi-solid slurry is obtained after water cooling. According to the method, by optimizing the corner angle of the equal channel angular extrusion die channel and combining graded speed regulation control in the extrusion process, stress concentration and severe plastic deformation of the as-cast blank can be well generated, and crystal grains are broken and fine, so that element segregation of the semi-solid slurry is improved, and the slurry with uniform solid and liquid and fine crystal grains is obtained.

The invention provides a preparation method of an aluminum alloy and a product thereof. According to the method, the anti-fatigue performance of the aluminum alloy is improved by adjusting the process sequence of multidirectional forging and pressing; the yield strength is improved through stabilizing treatment and differential temperature equal channel angular pressing; the uniformity of the anodic oxidation appearance of the aluminum alloy is improved by adding Cr and Mn elements; the corrosion resistance of the aluminum alloy material is improved through the dispersed phase pre-precipitation step; by reducing the viscosity of a molten aluminum alloy liquid phase, the pore generation rate of an aluminum alloy material during pulse laser welding is reduced.

A method for manufacturing an equiaxed crystal target includes steps. A bar-shaped metal material is formed to a forged material by using a radial forging process. The forged material is formed to a first plate material by using a rolling process and a plate forging process, wherein the rolling process is to roll the forged material along an axial direction thereof. An equal channel angular extrusion mold is used to reciprocally perform an equal channel angular extrusion process on the first plate material to obtain a second plate material, wherein a cumulative average equivalent strain of the second plate material is greater than 10, and a feeding direction of the first plate material into the equal channel angular extrusion mold is the same as the axial direction of the forged material. A recrystallization annealing / heat treatment process is performed on the second plate material to obtain an equiaxed crystal target.

The present invention belongs to the technical field of aluminum alloy rivet processing and discloses a method for preparing high-strength, corrosion-resistant rivets using 7050 aluminum alloy. The method comprises five process steps: homogenization heat treatment, equal channel angular extrusion, cold heading, aging heat treatment, and nano-coating spraying. The method improves the mechanical properties of the rivets after forming, integrates and simplifies the process flow in the rivet manufacturing process, and shortens the production cycle. The method not only ensures that the rivets after forming have a yield strength of 550 MPa, a hardness of 190 HV, and an elongation of 8-10%, and have good corrosion resistance, but also greatly shortens the aging time after forming.

The invention discloses a corrosion-resistant spoke forming process which comprises the following steps: firstly, refining an austenitic stainless steel wire into an ultra-fine grain / nanocrystalline structure through equal-channel angular extrusion in combination with low-temperature rolling, and improving the grain boundary density; then, surface pollutants are sequentially removed by adopting pulse fiber laser, an amorphous / nanocrystalline mixed activation layer is formed, and the surface activity is enhanced; mixed reaction gas is introduced into a closed reaction chamber, a gradient composite permeation layer composed of a ceramic phase outer layer, a mixed middle layer and a Cr / Ni-rich inner layer is formed at the temperature of 450-650 DEG C, and metallurgical bonding with a base body is achieved; finally, a porous ceramic membrane is generated on the surface of the permeation layer, and an indicator sensitive to Cl <-> or pH is filled through vacuum impregnation, so that the corrosion early warning function is achieved. The gradient infiltrated layer binding force critical load of the spoke obtained through the method is larger than or equal to 80 N, the salt spray test corrosion resistance time is larger than or equal to 2000 hours, and the spoke has the self-repairing capacity and the rapid corrosion early warning response, is suitable for various scenes such as bicycles, automobiles and ocean engineering and has the remarkable industrial application value.

The preparation technology comprises the following steps that magnesium alloy waste is subjected to low-temperature ball milling treatment to be made into nanoscale powder, the low-temperature ball milling temperature is smaller than or equal to 200 DEG C, the particle size of the powder obtained after ball milling is smaller than or equal to 100 nm, and argon is introduced in the ball milling process for protection so as to inhibit oxidation; the nano powder is mixed with Mg-Zn-Ca alloy powder with the mass ratio of 5-8%, spark plasma sintering SPS is adopted for densifying at 350-400 DEG C, the sintering pressure is 20 MPa, the heat preservation time is 10 min, and the density after sintering is larger than or equal to 98%; and performing equal channel angular pressing (ECAP) treatment on the sintered blank, wherein the extrusion temperature is 300 DEG C, the extrusion pass is four times, the included angle of a mold channel is 90 degrees, and the ultra-fine grain magnesium alloy with the average grain size of 2.1 microns is obtained. According to the preparation method disclosed by the invention, grain ultra-fining of 1.5-2.1 microns is realized through a multi-field coupling process, a non-basal plane slip system is activated at room temperature, the strain rate sensitive index m is greater than or equal to 0.35, the elongation at 250 DEG C reaches 280%, and the tensile strength of the magnesium alloy is greater than or equal to 250MPa. And high strength and superplastic deformation capacity are achieved.

The application provides a method for reciprocating equal-channel-angle-pressing strengthening of magnesium-zinc alloy, and belongs to the technical field of alloys. In the reciprocating ECAP process, high-temperature strain is used to activate the pyramidal <c+a> dislocation slip, so that a stronger deformation capacity is obtained, and dynamic recrystallization is induced, so that the generation of cracks in the material in the ECAP process is avoided, and multiple passes can be implemented to obtain a more fine and uniform microstructure and higher strength and plasticity. Meanwhile, in the high-temperature strain process, the uniform dynamic segregation of precipitated phases occurs at the grain boundaries, the migration of the grain boundaries is inhibited, and the recrystallized grains are uniformly refined. By controlling the angle of the equal-channel-angle-pressing die and the extrusion passes, the magnesium-zinc alloy can have finer grains and more stable grain boundaries, so that the strength and plasticity of the magnesium-zinc alloy are simultaneously improved, and therefore the magnesium-zinc alloy has better comprehensive mechanical properties.