269 results about "Severe plastic deformation" patented technology

Methods of refining the grain size of titanium and titanium alloys include thermally managed high strain rate multi-axis forging. A high strain rate adiabatically heats an internal region of the workpiece during forging, and a thermal management system is used to heat an external surface region to the workpiece forging temperature, while the internal region is allowed to cool to the workpiece forging temperature. A further method includes multiple upset and draw forging titanium or a titanium alloy using a strain rate less than is used in conventional open die forging of titanium and titanium alloys. Incremental workpiece rotation and draw forging causes severe plastic deformation and grain refinement in the titanium or titanium alloy forging.

The invention relates to the field of surface coating preparation and particularly relates to a cold spray device and method for preparing a metal composite gradient quasicrystal coating. A quasicrystal powder feeder and a metal or alloy powder feeder of the device are respectively connected to a gas-solid mixing chamber through a pipeline to form a dual-channel powder feeding structure, a quasicrystal heater and a metal or alloy powder heater are respectively arranged on the pipelines, a gas heater is connected with the gas-solid mixing chamber through a pipeline and a supersonic flow nozzle is arranged at an outlet of the gas-solid mixing chamber. One path of the gas source compressed gas enters into the quasicrystal powder feeder, one path enters into the metal powder feeder, and one path enters into the heater, the gas and the powders enter into the supersonic flow nozzle via the gas-solid mixing chamber to form gas-solid dual-phase flow, solid particles in the gas-solid dual-phase flow are injected onto the surface of a workpiece and generate severe plastic deformation and finally deposit on the surface of the workpiece. The method provided by the invention can solve the problems of fragility and phase change and the like of coatings, and can be used for preparing two-component or multi-component alloy quasicrystal gradient coatings of various series.

A method of processing a billet of metallic material in a continuous manner to produce severe plastic deformation. The billet is moved through a series of CSPD dies in one operation to efficiently produce a billet characterized by a controlled grain structure. The long billets of metal stock are moved along the processing path through the CSPD dies with plural sets of pinch rolls which grip the billet and push it into the entry channel of the dies. Other sets of pinch rolls pull the billet from the exit channel of the dies.

The invention discloses a pin tool used for friction stir welding, which integrates an electromagnetic vibration system, an electromagnetic action system, an internal forced cooling system, a gas-shielded forced cooling system, a temperature induction system and a sealing and insulation system, and is an integrated pin tool used for friction stir welding, which has the functions of electromagnetic vibration in-situ composite electromagnetic action, forced temperature control, gas shielding and temperature detection, and a device thereof is further disclosed, and can be applied in electromagnetic vibration in-situ composite electromagnetic action friction stir welding and the preparation of ultrafine grain materials with large thickness and large area by severe plastic deformation.

The invention discloses a particle reinforced metal-based composite material product (rods, wires, sheets or belts, or parts) which is obtained, based on the severe plastic deformation theory of material, by the step of performing severe plastic/accumulated deformation processing on a particle reinforced metal-based composite material so that second phase particles agglomerated in a metallic matrix are uniformly distributed (dispersed) in the matrix, and then carrying out subsequent processing, thereby enhancing the quality and the yield of the particle reinforced composite material and lowering the processing cost of the material, and thus a particle reinforced metal-based composite material having the characteristic of the uniformly distributed second phase particles and excellent performance is obtained.

A method for preparing block nano-magnesium alloy by utilizing twinning deformation comprises: magnesium alloy cast ingots or extruded bars are cut into rectangular blocks; compression twin crystal deformation with multiple channels and axes is respectively carried out along three direction of X axis, Y axis and Z axis of the rectangular block at the room temperature; the true strain capacity and the strain rate at every channel are controlled; when the true strain capacities along all the directions are accumulated to reach at least 1.5h, the twin crystal reinforced block nano-magnesium alloy having the average size being less than 0.5mum can be obtained. The method has simple processing technique and equipment requirements as well as convenient operation, and can overcome the problems of incontrollable recrystallization, poor effect of strain accumulation and difficult scale in severe plastic deformation of the prior art when in thinning magnesium alloy crystal grains; the method can be used for preparing large dense superfine grained magnesium alloy material and has good industrial application prospect.

The invention relates to the field of new techniques of laser processing and vibration aging, in particular to a surface strengthening method for a metal component by vibration-assisted laser shock treatment. According to the method, by combining laser shock strengthening technology with vibration aging treatment, a vibration exciter is used to excite vibration, a sensor picks up vibration, the vibration frequency is controlled to keep the amplitude value within a specified range, laser lap impact strengthening treatment is carried out with the aid of vibration aging treatment so that more serious plastic deformation can be generated on the surface of the metal component, and high-amplitude residual compressive stress is induced in an impact area; meanwhile under the condition that laser beam irradiates the metal surface, vibration further refines or even nanocrystallizes the surface grain, and under the action of the temperature field, vibration reduces the thermal stress field gradient, and thus the residual stress inside the material is uniformized; and the mechanical properties of the metal component are remarkably improved, and the metal surface is strengthened, so that the fatigue life of the metal component is prolonged effectively, and initiation and expansion of fatigue cracks are prevented.

The invention discloses a method for preparing a graphene reinforced aluminum-based composite with multi-layer graphene nanoplatelets as raw materials, and relates to a method for the graphene reinforced aluminum-based composite. The method aims to solve the problems that the dispersion difficulty of single-layer or few-layer graphene is high in the preparation method of a graphene reinforced aluminum-based composite at present and the cost of the graphene reinforced aluminum-based composite is high. The preparation method comprises the steps that the multi-layer graphene nanoplatelets, aluminum metal and commercial pure aluminum blocks are weighed; secondly, the multi-layer graphene nanoplatelets are dispersed, and precast blocks are molded; thirdly, the aluminum metal is infiltrated; fourthly, severe plastic deformation treatment is conducted; and fifthly, composition homogenization treatment is conducted. The low-cost multi-layer graphene nanoplatelets are used as reinforcement raw materials, so that the cost is obviously lowered compared with composites with few-layer graphene as reinforcements directly; and the prepared graphene reinforced aluminum-based composite is excellent in comprehensive performance, and industrialization production and application can be achieved easily. The method is suitable for preparation of the graphene reinforced aluminum-based composite.

The invention discloses a preparation method of a nanocrystalline magnesium alloy by continuous and severe plastic deformation. The method comprises the following steps of: firstly, smelting a prepared magnesium alloy raw material and casting into a round cast ingot; then, thermally extruding at 340-460 DEG C to a bar with diameter of 9-12mm; cutting the extruded round bar and performing equal channel corner extrusion with 4-8 channels at 200-350 DEG C; and then, cutting the bar into wafer samples which are 0.8-1mm in thickness for twisting at room temperature and high pressure, wherein the pressure is 4-6Gpa and twisting for 2-10 rings. According to the method provided by the invention, conventional thermal extrusion is combined with equal channel corner extrusion and high pressure twisting belonging to a severe plastic deformation process, and the magnesium alloy with the average grain size below 100nm and uniform tissue can be easily prepared, so that the mechanical property of the magnesium alloy is greatly improved, and meanwhile, the method has the characteristics of large size of nanocrystalline magnesium alloy material, simple process, high processing efficiency, less impurities and defects and the like.

The invention relates to a preparation method of a composite and particularly relates to a preparation method of a nano graphene copper foil. The nano graphene copper foil can be applied to the field of lithium battery negative current collectors. The preparation method of the nano graphene copper foil comprises the following steps: uniformly coating graphene on the surface of a copper belt, folding a copper foil with surface coated by the graphene, accumulating rolling severe plastic deformation to obtain a graphene copper belt with a nano microstructure, cold rolling a nano graphene copper belt in which the graphene is uniformly distributed for four times, rolling the nano graphene copper belt in a manner of continuously reducing thickness to form the required specification of nano graphene copper foil.

The invention discloses a preparation method of a magnesium alloy wire based on severe plastic deformation. The method comprises the following steps of: first, melting and pouring a magnesium alloy material to pole cast ingots with the diameter over 20mm; then, thermally extruding the cast ingots to fine pole bars with the diameter of 5-8mm at extrusion ratio of 16-36 at 300-360 DEG C; after sectioning the extruded poles and extruding the poles with 4-8 paths of equal channel corners at 200-300 DEG C; then, drawing the bars at room temperature; when the material accumulative percentage reduction of area is 70+/-5%, annealing at 150-200 DEG C for 3-10 minutes; and repeating drawing and annealing till wires in required dimension are prepared. According to the invention, severe plastic deformation is performed on the magnesium alloy bars through an equal channel extruding process before drawing to greatly reduce the original grain size of magnesium alloy to be drawn, so that the drawing performance of the magnesium alloy and the comprehensive mechanical performance of final wires can be remarkably improved.

The invention provides a preparation method of high-purity titanium powder. The method includes the steps: selecting high-purity molten salt electrolysis titanium as raw materials, obtaining ultra-fine grain titanium materials by a high-pressure torsion method, and enabling the titanium raw materials to absorb heat to generate hydrogen absorption reaction, tender and easily crush to a certain particle size by a hydrogenation-dehydrogenation and mechanical ball milling method under a special process control condition; performing dehydrogenation for the titanium raw materials; finally, further crushing the titanium raw materials to obtain ultra-fine high-purity titanium powder. The used raw materials are not sponge titanium obtained by a traditional magnesium heating method, the process is more environmentally friendly, the molten salt electrolysis titanium is high in purity and low in oxygen content, the ultra-fine grain titanium materials treated by severe plastic deformation of high-pressure torsion has high dislocation density and inner stress and a wide-angle non-equilibrium grain boundary, the hydrogenation temperature of the treated ultra-fine grain titanium materials is obviously reduced as compared with untreated titanium materials, raw material oxidation caused by over-high temperature can be effectively reduced, the particle sizes of the prepared titanium powder are small and uniform, and various production requirements are met.

A device and method for continuous forward extrusion and twist extrusion composite molding belong to the technical field of machining. The device and method for continuous forward extrusion and twist extrusion composite molding are intended for solving the problems of many steps and high process requirements of an existing severe plastic deformation method, and have the following technical features: the device is constituted by three stages of extrusion passages; each stage of extrusion passages includes a forward extrusion passage and a twist extrusion passage; the forward extrusion passages allow reduction of the cross sectional area of a blank; after the blank passes through the three stages of extrusion passages, the cross sectional area of the blank is reduced gradually with gradual refining of grains, and therefore, a fine grain material is prepared. A preparation method provided by the present invention comprises the following steps: placing the device on a press machine and carrying out heating to a specified temperature; putting a blank into the device and then putting a punch thereinto; allowing the punch to go down to orderly complete forward extrusion and twist extrusion in each stage of extrusion passages, thus forming a final rectangular bar. The device and method for continuous forward extrusion and twist extrusion composite molding are used for composite molding of rectangular bars.

The invention provides a severe plastic deformation method for manufacturing ultra-fine grain material, which comprises an equal-channel angular extrusion step. The method is characterized in that the severe plastic deformation method has the following processing steps, namely the preparation of raw material, homogenizing annealing, compression extrusion deformation, equal-channel angular extrusion deformation, repeated upsetting-extrusion deformation, and annealing treatment. The shapes and sizes of the material before and after the extrusion deformation are the same so as to realize the multi-pass accumulated deformation; combining the other technologies, the disadvantages during the manufacture process of the ultra-fine grain material are effectively avoided because of absorbing the advantages of a equal-channel angular extrusion method, thereby realizing that the uniform ultra-fine grain microstructure material can be obtained after less-pass upsetting-extrusion deformation; therefore, the uniform and stable ultra-fine grain bulk material is obtained, in addition, the productivity effect is increased obviously, the service life of an extrusion die is prolonged, the manufacturing cost is lowered, and the severe plastic deformation method is favorable for realizing large-scale industrial production at the same time.

The invention discloses a severe plastic deformation method and a severe plastic deformation device for pressing and rolling the corner of a non-equal channel. According to the severe plastic deformation method and the severe plastic deformation device for pressing and rolling the corner of the non-equal channel, an equal-channel angular pressing (ECAP) technology and an ARB (Accumulative Roll Bonding) technology are integrated. The concrete process comprises the following steps that pressing force is applied after a test sample, a punching head and a mould are simultaneously preheated to pressing and rolling temperature, so that the test sample passes through the position of the channel corner of the device for pressing and rolling the corner of the non-equal channel completely; compressive deformation is generated when shear deformation is generated by the test sample so as to finish a first pass pressing and rolling process; the test sample is cut into L1/L2 parts along a length direction, and the L1/L2 parts are placed in an I channel; and the steps are repeated so as to finish multi-pass pressing and rolling deformation. The mould of the device is provided with the I channel and an II channel which are intersected and also have non-equal sections. The design is reasonable, the structure is simple, and the manufacturing cost is low. According to the method disclosed by the invention, the advantages of the ECAP technology and the ARB technology are integrated, and the mechanical property of a material is effectively enhanced. The process is short in procedure, high in efficiency and low in cost and is simple to operate. The severe plastic deformation method and the severe plastic deformation device for pressing and rolling the corner of the non-equal channel can be widely used for the field of processing metal materials, such as pure metal and alloy.

The invention relates to the technical field of metal strengthening, in particular to a method for improving the mechanical surface strengthening effect. According to the method, before mechanical surface strengthening treatment is conducted, a certain surface structure is machined on the surface of a treated metal material. The method for improving the mechanical surface strengthening effect includes the steps that the surface structure is machined before mechanical surface strengthening treatment is conducted, a larger and deeper residual compressive stress layer can be generated on the treated surface through mechanical surface strengthening treatment; residual compressive stress with preset directivity can be generated on the treated surface through mechanical surface strengthening treatment; the residual compressive stress value of the topmost surface is increased, so that the mechanical surface strengthening effect is further enhanced; and the treated surface layer is more likely to generate severe plastic deformation and grain refinement, and an ultra-fine grain or a nanocrystal surface layer material is prepared conveniently.

A high-entropy alloy having ultra-high strength and high hydrogen embrittlement resistance due to formation of a microstructure at a low strain may be produced without a severe plastic deformation.

A method for producing the high-entropy alloy includes (a) annealing and homogenizing an initial alloy material at 1000 to 1200° C. for 1 to 24 hours; and (b) rolling the annealed and homogenized initial alloy material into a rod, at a cryogenic temperature of −100 to −200° C. while pressing the initial alloy material in multi-axial directions at a strain of 0.4 to 1.2, thereby to produce the high-entropy alloy having intersecting twins as a microstructure, and secondary fine twins formed in the intersecting twins, wherein the initial alloy material contains Co of 5 to 35%, Cr of 5 to 35%, Fe of 5 to 35%, Mn of 5 to 35%, and Ni of 5 to 35%, based on weight %.

To provide a lubricant for plastic processing of metal materials which is also applicable in severe plastic deformation applications, does not have a black appearance that significantly stains a working environment, and does not tend to generate lubrication residue that cause molding defects. A lubricant for plastic processing of metal materials characterized by comprising in the range of 5-95%, in solid content ratio, an organic modified clay mineral supporting a cationic organic compound between the layers of the layered clay mineral.

The invention provides a method for eliminating the original grain boundary of a nickel-based powder metallurgy superalloy, belonging to the technical field of superalloys. According to the invention,the method adopts hot isostatic pressing and intense-plastic-deformation hot extrusion at a temperature below the complete dissolution temperature of a gamma' phase, makes full use of the pinning effect of the gamma' phase on the grain boundary in the hot isostatic pressing stage to control the grain size of the superalloy and prevent excessive grain growth, and then carries out optimized designon hot extrusion parameters to further refine grains and to crush and eliminate the original powder grain boundary. The method provided by the invention can eliminate the original grain boundary in the nickel-based powder metallurgy superalloy and prepare workpieces with particularly fine and uniform grain sizes.