98results about How to "Remarkable grain refinement effect" patented technology

The invention relates to a high-speed steel roll and a preparation method thereof by centrifugal compounding in an electromagnetic field, belonging to the technical field of preparation of the high-speed steel roll. The components of a working layer material of the high-speed steel roll are as follows (in weight percent): 1.5 to 2.5 percent of C, 4.0 to 6.0 percent of V, 4.0 to 6.0 percent of W, 1.5 to 4.5 percent of Mo, 2.0 to 4.0 percent of Cr, 0.04 to 0.18 percent of Zr, 0.001 to 0.003 percent of B, less than or equal to 0.5 percent of Si, less than or equal to 0.5 percent of Mn, and the balance of Fe and impurity elements; and in the impurity elements, the required contents of S, P and O are respectively less than 0.01 percent, less than 0.01 percent and less than 0.0010 percent. The roll is cast by adopting a centrifugal compounding method in a pulse electromagnetic field, the frequency of the pulse magnetic field is 0.1 to 10Hz, and the peak strength of a central magnetic field of a cast mold is 1 to 10T. The roll has a plurality of precipitation strengthening phases, and the applied pulse magnetic field leads the strengthening phases and matrix crystal grains to be refined effectively and leads the strengthening phases to be distributed in a dispersed manner, thus overcoming the segregation of alloy elements and greatly improving the performance of the roll.

This invention relates to a method of manufacture supper slim crystal U shape passage repeat extrusion machine which belongs to the material field. The invention include: extrusion pole, gripe, right model cavity, left model cavity, arc shape model cavity, bolt, fillister. The fillister symmetry divided two part from center line, there are right model cavity, left model cavity, arc shape model cavity in the divided shape, left model cavity connect with right model cavity by arc shape model cavity, left and right model cavity have equal cross section acreage, same shape, center line parallel each other, the shape is square or rotundity. The arc shape model cavity has the same cross section acreage, same shape with left and right model cavity. The two parts fillister make up U shape extrusion equal section by bolt, extrusion pole is on the extrusion equal section passage, there is not gripe in the fillister. The invention has the simple frame, strong capacity of fine crystal, realize series work, it has prominent application of industry.

The invention relates to a method for modification and refinement of a hypoeutectic and eutectic Al-Si alloy. The hypoeutectic and eutectic Al-Si alloy with the Si content of 2-13.5 wt.% is subjected to modification and refinement treatment with Sr and B; after treatment, the Sr content in an alloy melt is 0.005-0.1%, the B content is 0.005-0.1%, and the mass ratio of Sr to B is 0.3-5. An Al-B intermediate alloy is used as a refiner, and has excellent grain refining effect on the Al-Si alloy; an Al-Sr intermediate alloy is used as a modifier, can effectively modify eutectic Si in the Al-Si alloy. By controlling melting, modification and refinement treatment processes, the grain refiner also has good refinement effect on alpha-Al while the added modifier has good modification effect on the eutectic Si, so that an ingot microstructure is simultaneously modified and refined, and a mutual poisoning effect between Sr and B can be effectively avoided.

The invention discloses a non-radiative multi-component composite tungsten negative material for a microwave oven magnetron and a preparation process of the negative material. The tungsten cathode material comprises lanthanum oxide, zirconium oxide, yttrium oxide, lutetium oxide, rhenium and tungsten, wherein the mass percent of each rare-earth oxide in the tungsten electrode material is 0.5%-1.5%, the mass percent of the total rare-earth oxides in the tungsten electrode is 2%-3%, the mass percent of the alloy element rhenium in the tungsten electrode material is 1%-4%, and the tungsten accounts for the rest mass percent. The tungsten cathode material is non-radiative, excellent in thermal emission performance, excellent in high-temperature creep resistance, thermal shock resistance and sag resistance, and long in service life. The preparation method of the non-radiative multi-component composite tungsten cathode material for the microwave oven magnetron comprises the steps of solution preparation, drying, reducing, isostatic cool pressing, sintering, incipient fusion, medium-frequency induction annealing, press working, winding and mechanical straightening. The non-radiative multi-component composite tungsten negative material for the microwave oven magnetron is better in usability. When heated periodically for a long time at a high temperature, the multi-component composite tungsten wire produced by virtue of the process is capable of going through large deformational resistance, and has the sag resistance.

The invention provides a method for preparing a nanocrystalline austenitic stainless steel plate through deep cooling rolling-rapid annealing and belongs to the field of stainless steel manufacturing. The method comprises the steps that (1) an austenitic stainless steel blank is hot-rolled after being subjected to heat preservation at the temperature of 1150 DEG C-1250 DEG C and then is air-cooled to the room temperature after being water-cooled to 150 DEG C-200 DEG C, and a hot-rolled plate is prepared; (2) deep cooling rolling is conducted, specifically, the hot-rolled plate is subjected to solid solution treatment, after an oxide layer on the surface is removed, deep cooling rolling is conducted, the steel plate is subjected to liquid nitrogen treatment before cold rolling per pass, and a deep cooling rolled stainless steel plate is prepared; and (3) the deep cooling rolled stainless steel plate is air-cooled to the room temperature after being subjected to heat preservation at the temperature of 600 DEG C-850 DEG C, so that the nanocrystalline austenitic stainless steel plate is prepared. The yield strength of the stainless steel plate prepared by the method is 956-1170 MPa, the tensile strength is 1130-1380 MPa, the percentage elongation after fracture is 18%-52%, and the product of strength and elongation is 55000-58080 MPa.%. According to the method for preparing the nanocrystalline austenitic stainless steel plate through deep cooling rolling-rapid annealing, the time is short; the efficiency is high; energy sources are saved; the cost is low; and a sample piece large in section size is easy to produce.

The invention provides a method for reinforcing a magnesium matrix composite by using magnesium oxide-coated graphene. The method comprises the following steps: mixing 0.1 to 5 g of magnesium oxide-coated graphene with no less than 250 ml of an ethanol solution and carrying out ultrasonic treatment for 1 to 2 h so as to obtain a magnesium oxide-coated graphene ethanol mixed liquor; adding magnesium alloy powder with mass of no less than 95 g and granularity of no more than 325 meshes into the mixed liquor and carrying out ultrasonic treatment and mechanical stirring for 1 to 3 h so as to obtain mixed slurry; carrying out filtering and vacuum drying on the mixed slurry, then transferring the obtained substance to a die and carrying out cold pressing at room temperature under a pressure of 100 to 600 MPa; sintering a cold-pressed composite at 500 to 600 DEG C under the protection of argon for 2 to 4 h; carrying out hot extrusion on the sintered composite at 350 to 400 DEG C; and subjecting the extruded composite to T6 heat treatment. The method has the advantages of low process cost, safety, reliability and simple operation; the magnesium oxide-coated graphene is uniformly distributed in magnesium alloy and has high bonding strength with a matrix interface, obvious grain refinement effect is obtained, and the composite has excellent performance; and the method can realize industrial preparation of the high-performance graphene-reinforced magnesium alloy composite.

The invention provides a magnesium alloy bar power ultrasonic semi-continuous casting and flaw detection device and method. The magnesium alloy bar power ultrasonic semi-continuous casting and flaw detection device comprises a power ultrasonic generating device, an ultrasonic flaw detection processing system and a vertical direct water-cooling semi-continuous casting machine. The power ultrasonic generating device comprises an ultrasonic generator, an ultrasonic time-sharing vibration control system and three ultrasonic transmitting assemblies with the same specification. Each ultrasonic transmitting assembly comprises an ultrasonic transducer, an ultrasonic amplitude transformer and a tool head. The ultrasonic flaw detection processing system comprises an ultrasonic receiving sensor, a signal processing and determination module and an ultrasonic flaw detection display screen. The ultrasonic transmitting assemblies are inserted into molten magnesium alloy at the same time, and controlled by the ultrasonic time-sharing vibration control system to transmit power ultrasound at intervals, and the molten magnesium alloy solidifies under the action of an ultrasonic field so that fine-grain cast bars can be obtained. Ultrasonic waves transmitted by the ultrasonic transmitting assemblies serve as a signal source, the waveforms of the ultrasonic waves are processed through the ultrasonic receiving sensor and the signal processing and determination module, and the internal flaw conditions of the cast bars are determined according to prompts on the ultrasonic flaw detection display screen.

The invention relates to a semisolid alloy preparation method, in particular a method for preparing a spherical primary crystal semisolid alloy through centrifuging and chilling. The method comprises the following steps of: first, melting the alloy to a certain temperature; and then pouring the melt in a centrifugal barrel; throwing the melt to the inner wall of a chilling barrel after rotating the melt through centrifugal force; carrying out mixed convection on the melt in the centrifugal barrel under the double effects of centrifugal force and chilling force; and finally, obtaining a non-dendritic semisolid alloy blank or slurry with spherical or granular primary phase under the mutual effect of numerous nucleation and dendrite breaking of the outer barrel. The method for preparing the spherical primary crystal semisolid alloy through centrifuging and chilling, provided by the invention, has the characteristics of simple equipment, high production efficiency, wide application range of alloy, fine and rounded primary phase with semi-solid structure and the like, and can be used for the preparation and molding production of the metal semisolid alloy.

The invention discloses a blocked type variable cross-section reciprocating squeezing, twisting and upsetting forming method for ultra-fine grain bars. On the basis of a three-way hydraulic forming machine, the die assembly force is provided through an upper slide block, and pressure required for forming of punches at the two ends is provided through a left slide block and a right slide block. A die inner cavity is a linear channel formed by sequentially connecting a first squeezing channel, a middle twisting channel and a second squeezing channel on the same straight line. The section area of the middle twisting channel is smaller than the section area of the first squeezing channel and the section area of the second squeezing channel. The punches at the two ends are located at the two ends of the linear channel in a one-to-one correspondence manner, and a blocked variable section cavity is formed through the reciprocating punches at the two ends. By means of reciprocating of the punches at the two ends, the reciprocating squeezing, twisting and upsetting process of a to-be-processed blank in the linear channel is achieved, and preparation of the ultra-fine grain bars is completed through multi-pass forming. By means of the blocked type variable cross-section reciprocating squeezing, twisting and upsetting forming method, bar grains can be effectively refined, the forming limit of the bars is improved, and the blocked type variable cross-section reciprocating squeezing, twisting and upsetting forming method is easy to operate, high in applicability and capable of being easily applied in an engineered manner.

The invention relates to a method for preparing an Al-Ti-C grain refiner. The method comprises the following steps of: smelting titanium into an aluminium solution, controlling the temperature within a range from 800 to 1,400 DEG C, preserving the heat, and dispersing nano TiC into a titanium and aluminium melt by adopting nitrogen or argon to obtain the Al-Ti-C grain refiner. By the method, required equipment is simple; the technical flow is short; the preparation efficiency is high; TiC particles can be dispersed; and the method is simple and feasible. The Al-Ti-C grain refiner prepared by the method has a good grain refining effect; 0.2 percent of Al-Ti-C grain refiner is added into pure aluminium, and the heat is preserved for 2 hours, but the refining effect is not obviously decayed; and the Al-Ti-C grain refiner has good industrial application prospect.

A method for preparing nanocrystalline magnesium alloy powder relates to the preparing method of magnesium alloy powder, which solves the problem that the machinery method prepares the powder with long time of ball milling, easy oxidation and low producing efficiency. In the fast solidify method for preparing the powder, only a very few magnesium alloy with exceptive alloy ingredient can obtain the nanocrystalline due to limit by thermodynamics condition. For most of magnesium alloy, crystal grain only can be refined to a range from 1 um to 3 um. The method of the invention is that magnesium alloy ingot is crushed to rough power, the rough power of the first step is put into a goal agate jar, the goal agate jar is vacuum and charged with hydrogen, the rough power is rub with machine in full hydrogen condition and the hydride state nanocrystalline magnesium alloy powder is dehydrogenated in vacuum by heating to get the nanocrystalline magnesium alloy powder material. The invention integrates the hydrogen processing and the machine goal agate method, therefore, the effect of crystal grain refinement is prominent and nanocrystalline is quickly obtained. The invention has the advantages of good thermal stability of hydride state powder, even organization and uneasy oxidation.

The invention discloses a high-temperature alterant, which comprises the following components in percentage by weight: 15 to 20 percent of chloride, 40 to 45 percent of chloride, 25 to 30 percent of rare earth metal compound, 3 to 8 percent of titanium dioxide, and 2 to 6 percent of graphite. The invention also discloses a method for purifying a fusant, wherein the high-temperature alterant is added into a smelting furnace. The high-temperature alterant can reduce the sodium content in an electrolytic molten aluminum fusant and effectively control the grain size to achieve good grain refining effect. The method for purifying the fusant can effectively reduce gas and foreign impurities in the fusant, optimize the production process, ensure the quality of aluminum and aluminum alloy fusants, improve the ingot yield, save the energy consumption, and reduce the discharge of pollutants.

The invention discloses a high-strength corrosion-resistant AL-Mg alloy. The high-strength corrosion-resistant AL-Mg alloy comprises the following chemical components in percentage by weight: less than or equal to 0.3% of Fe, less than or equal to 0.25% of Si, less than or equal to 0.1% of Cu, 0.4-1.2% of Mn, 4.5-6.0% of Mg, 0.25-0.55% of Zn, 0.10-0.3% of Cr, less than or equal to 0.15% of Zr, less than or equal to 0.15% of Ti, and the balance of Al. The high-strength corrosion-resistant AL-Mg alloy solves the problems that the strength and the corrosion resistance of the conventional aluminum alloy 5083 in the manufacturing of a traffic tool are not good, the tensile strength of the obtained alloy sigma b is more than or equal to 320Mpa, the yield strength sigma 0.2 is more than or equal to 160 Mpa, the ductility delta is more than or equal to 23%, and the grade of an exfoliation corrosion test reaches PA level.

The invention discloses a production method for a nucleating agent for a high-strength thin-wall gray pig iron casting. Raw materials including, by weight percent, 65%-75% of Si, 0.5%-1% of Zr, 0.5%-1% of Re, 0%-0.5% of Al, 1.5%-2.5% of Ba, 0.5%-0.8% of Ca and the balance Fe and inevitable impurities are mixed and smelted, then alloy powder with the average grain size ranging from 200 microns to 300 microns are produced, then the alloy powder is mixed with nano silicon carbide water scattering liquid, atomizing and drying are conducted, the nano silicon carbide is doped in the alloy powder, and the nucleating agent for the high-strength thin-wall gray pig iron casting is obtained. The prepared nucleating agent has a good grain refining effect, the strength of the casting is improved, the uniformity of matrix structures of the casting can be guaranteed as well, generation of inner defects of the casting is reduced, and the nucleating agent is suitable for being applied to inoculation treatment on the high-strength thin-wall gray pig iron casting.

The invention provides a method for reinforcing a magnesium matrix composite through carbon nanotubes coated with magnesium oxide. 1-5 g of carbon nanotubes chemically coated with magnesium oxide and larger than or equal to 250ml of an acetone solution are mixed and then subjected to ultrasonic dispersion for 1-4 h to obtain uniformly dispersed carbon nanotube and acetone mixed liquor; AZ91 magnesium alloy powder with mass larger than or equal to 95 g and grain size smaller than or equal to 325 meshes is added to the mixed liquor, and then the mixed liquor is stirred mechanically under ultrasonic waves for 1-4 h to obtain mixed slurry; the mixed slurry is subjected to filtration and vacuum drying, then transferred into a die, and subjected to cold pressing under the pressure of 100-600 MPa at a room temperature; a composite after cold pressing is sintered for 2-4 h under the protection of argon at the temperature of 500-600 DEG C; the sintered composite is subjected to hot extrusion at the temperature of 350-400 DEG C. The method is low in process cost, safe, reliable and easy to operate; the carbon nanotubes coated with magnesium oxide are uniformly distributed in magnesium alloy and have high bonding strength with interfaces of matrixes, the grain refinement effect is remarkable, the composite has excellent performance and the method is suitable for industrially preparing the high-performance magnesium alloy composite reinforced by the carbon nanotubes.

The invention relates to the technical field of metal surface cladding materials, and in particular relates to a steel wire hot dipping rare earth zinc alloy and a hot dipping method. With the method, the hot dipping alloy is adopted to carry out hot dipping on steel wires, and a pulsed magnet field is applied to a hot dipping alloy molten pool in the hot dipping process. The hot dipping alloy comprises the following components in percentage by mass: 0.02-0.06% of rare earth mixture 1 or rare earth mixture 2, 4.0-4.5% of Al, 0.11-0.2% of Ti, 0.05-0.10% of B, 0.01-0.05% of Sr and the balance of Zn and inevitable impurities, wherein the rare earth mixture 1 is composed of at least two of rare earth Ce, La and Pr at the mass ratio of 1:1, and the rare earth mixture 2 is composed of rare earth Ce, La and Pr at the mass ratio of 1:1:1. The parameter range of the pulsed magnet field is that the pulse width is 80-100ms, the action frequency is 1-2Hz, and the peak value intensity of the pulsed magnet field is 11-15T. According to the steel wire hot dipping rare earth zinc alloy, the clapping material quality is improved, and the consumption of rare earth and other metals is saved. The technology applied in the method is simple, and the existing technical equipment is mature, has low cost and is worthy of popularization.

The invention discloses an aluminium calcium carbon grain refiner for Mg-Al series magnesium alloy and a preparation method and application thereof. The grain refiner provided by the invention comprises aluminium, calcium, carbon and magnesium; and by adding the aluminium calcium carbon grain refiner to magnesium alloy melt, fine heterogeneous phase particles, i.e. Al4C3, supply a large number of effective heterogeneous nucleation cores, Ca solute released by dissolved CaA12 (or CaAl4) particles restrains the growth of magnesium alloy grains, and the casting-state magnesium alloy grains are obviously refined and increased in terms of strength and plasticity under the composite refining effect. The grain refiner provided by using the method is a metal block and is convenient to add in the magnesium alloy melt; the addition amount and the component content of the grain refiner are easily controlled; and the purpose of high efficiency refinement can be achieved by adding a trace of grain refiner.

The invention relates to the technical field of machining, in particular to an equal-distance rolling method of a spiral conic roller of a large-size 45 steel ultra-fine grain bar. The equal-distancerolling method comprises the following steps that S1, a 45 steel blank with the diameter dimension D ranging from 40 mm to 150 mm and the length ranging from 300 mm to 5000 mm is selected; S2, the 45steel blank is placed in a heating furnace to be heated to range from 850 DEG C to 980 DEG C; S3, the heated 45 steel blank is transferred into a guide chute of an inclined rolling machine from the heating furnace; S4, feeding is carried out in the guide chute of the inclined rolling machine, the 45 steel blank is fed into a deformation area between an inlet and an outlet of the inclined rolling machine, and the 45 steel blank spirally moves in the deformation area till deformation is finished; and S5, the steps from S2 to S4 are repeated, and the 45 steel blank is spirally rolled two to ten times to obtain the 45 steel overall ultra-fine grain bar. The equal-distance rolling method has the advantages that the penetration depth of the deformation area is large, and multi-pass rolling can be carried out in a reciprocating manner. Continuous and stable partial deformation is achieved, pressing-twisting composite three-dimensional severe deformation is achieved, and the ideal grain refining effect can be obtained.

The invention discloses an equal-channel corner revolving extrusion die and method and belongs to the field of material machining. The die comprises bolts and die sections, bolt holes are respectively and correspondingly arranged in the two die sections, and the two die sections are fastened with the bolts. Parting surfaces of the two die sections cling to each other completely to form a structure with the center being an extrusion cavity of the die, the extrusion cavity is an equal-channel corner extrusion die cavity, and the equal-channel corner extrusion die cavity is sequentially provided with a die cavity leading-in section, a die cavity leading-in transition section, a die cavity corner section, a die cavity leading-out transition section, a die cavity leading0out section and a die cavity taking-out section. The equal-channel corner revolving extrusion die has the advantages of high grain refining capability, convenience in operation, simple structure and continuous extrusion.

The invention discloses a method for improving mechanical properties of 301LN austenitic stainless steel and belongs to the stainless steel preparation field. According to the method, a 301LN austenitic stainless steel blank which is 40-60 mm thick is subjected to hot rolling till a plate which is 4-5 mm thick is obtained; then cold rolling-annealing process treatment is performed; and the 301LN austenitic stainless steel with the yielding strength ranging from 700 MPa to 1000 MPa, the tensile strength ranging from 1000 MPa to 1200 MPa and the ductility larger than 30% is prepared. The method is easy to operate, and industrial production can be achieved conveniently.

The invention discloses an Al-TiO2-C grain refiner, a preparation method thereof and a commercial-purity aluminum refining method. The Al-TiO2-C grain refiner is composed of Al powder, TiO2 powder and C powder. The preparation method of the Al-TiO2-C grain refiner comprises the steps that 1, the Al powder, the TiO2 powder and the C powder are mixed and then processed on a star type ball mill through ball milling for 0.5-2 h; 2, a precast block with the diameter phi being 30 is pressed on a universal tester, wherein 85 KN pressure is used for block pressing; 3, the precast block is wrapped by aluminum foil, and air between the precast block and the aluminum foil is extruded for storage; 4, the precast block is sintered in a high-temperature sintering furnace; and 5, furnace cooling is carried out, then the sintered precast block is taken out, and therefore the prepared Al-TiO2-C grain refiner is obtained. Precipitated phases of the prepared Al-TiO2-C grain refiner are TiC, Al2O3 and Al3Ti phases. The Al-TiO2-C grain refiner has the good grain refining effect. By adjusting the ratio of C to TiO2, the TiO2 addition, pressure needed for precast block preparation and the like, Al2O3 with the appropriate amount is contained in the Al-TiO2-C grain refiner structure and distributed in a relatively dispersed mode, and the better grain refining effect is achieved.

The invention discloses a grain refiner for ferritic stainless steel continuous casting. The grain refiner comprises, by weight percentage, 0.01%-0.05% of TiC powder and 99.95%-99.99% of pure Fe powder; the grain size of the TiC powder is smaller than 1 micrometer, the grain size of the pure Fe powder ranges from 10 micrometers to 20 micrometers, and the density of particles of the TiC powder in the grain refiner is larger than 20000 units / mm<3>. The preparing method of the grain refiner includes the following steps that (1) material grinding is carried out, wherein large-particle TiC prepared through a carbon thermal reduction process is placed into a planetary mill to be ground, grinding is carried out until the mean grain size is smaller than 1 micrometer, and micron order TiC powder is obtained; (2) even mixing is carried out, wherein the obtained micron order TiC powder and the pure Fe powder with the grain size ranging from 10 micrometers to 20 micrometers are weighed according to the weight percentages of the raw materials to be placed into a ball mill for even mixing; and (3) hot isostatic pressure molding is carried out, wherein mixed powder obtained after even mixing in the step (2) is subject to hot isostatic pressure molding. During ferritic stainless steel continuous casting production, the grain refiner is added, the proportion of columnar crystals of a ferritic stainless steel continuous casting blank is greatly reduced, the isometric crystal proportion is improved to 70% or above, and the grain refinement effect is remarkable.

The invention belongs to the field of metal materials and relates to aluminum-titanium-iron-carbon-boron intermediate alloy for refining aluminum and aluminum alloy and a preparation method thereof. The aluminum-titanium-iron-carbon-boron intermediate alloy comprises five elements, i.e. aluminum, titanium, iron, carbon and boron and comprises the following the components in percentage by weight: 85-95 percent of aluminum, 1.00-10.00 percent of titanium, 0.10-6.50 percent of iron, 0.01-1.00 percent of carbon and 0.01-1.00 percent of boron. The preparation method of the aluminum-titanium-iron-carbon-boron intermediate alloy comprises the following steps of: putting the pure aluminum into an intermediate frequency furnace to smelt and raising the temperature to 850-1300 DEG C; adding a certain mass percentage of pure titanium, iron-boron-carbon middle intermediate alloy and graphite, heat-insulating and agitating for 5-30 minutes to pour into an ingot or a make into a wire. The preparation method has the advantages of simple process, environment friendliness and low cost and is suitable for industrial production; the prepared aluminum-titanium-iron-carbon-boron intermediate alloy hasexcellent crystal grain refining effect on the aluminum and the aluminum alloy.

The invention provides a spiral tapered roll type equal-roll-spacing rolling method of a large-size ultrafine aluminum alloy crystal bar, and relates to the technical field of mechanical processing. The method comprises the steps of S1, selecting an aluminum alloy blank of which the diameter D is 40-200nm and the length is 300-5000mm; S2, feeding the aluminum alloy blank into a heating furnace, and heating to reach the temperature of 380-450 DEG C; S3, transferring the heated aluminum alloy blank from the heating furnace into a material guide groove of a skew rolling mill; S4, feeding materials into the material guide groove of the skew rolling mill; feeding the aluminum alloy blank between a deformation area between an inlet and an outlet of the skew rolling mill; and spirally moving thealuminum alloy blank in the deformation area until the deformation is finished; and S5, repeating the steps S2-S4; and spirally rolling the aluminum alloy blank in 2 to 14 times to obtain an integralultrafine aluminum alloy bar. The method has the beneficial effects that the deformation area is high in penetration depth; and the rolling can be performed in a plurality of times in a reciprocatingmanner; the local deformation is continuously stably performed; the pressing-twisting combined three-dimensional severe deformation is carried out; and ideal grain refining effect is obtained.

The invention provides a novel non-rare earth cast magnesium alloy. The alloy is an Mg-Bi-Zr-Zn alloy and comprises the following components by weight percent: 0.5-8wt% of Bi, 0.35-1.0wt% of Zr, 0.1-2.0wt% of Zn and the balance of Mg. The novel non-rare earth cast magnesium alloy has the beneficial effects that the obvious grain refinement effect of the element Zr in an Mg-Bi alloy series is found on the basis of Mg-Bi, thus improving the strength and plasticity of the alloy; the strength of the alloy is improved in an auxiliary manner by using a small quantity of the element zinc, thus developing the high-strength cast magnesium alloy from the alloy series; the yield strength is 140-155MPa; the tensile strength is 245-285MPa; and the elongation is about 6.5%.

The invention provides a refining method for CuAlMn shape memory alloy grains and relates to a physical structure for changing a copper base alloy. The refining method includes the steps that a nucleating agent Cu51Zr14 is prepared; the copper base shape memory alloy containing, by mass percentage, 11.9% of Cu, 2.5% of Al and the balance Mn is taken to be put into a medium-frequency induction furnace to be molten and then is moved into a well type crucible furnace, the temperature is kept at 1090 DEG C to 1100 DEG C for 5 minutes to 8 minutes, and then the smashed nucleating agent Cu51Zr14 accounting for 0.1% to 1.0% the total mass of the copper base shape memory alloy is put into the furnace to be stirred for 10 seconds to 15 seconds and is poured into a steel die after residues are removed, so that refining of the CuAlMn shape memory alloy grains is completed. By the adoption of the refining method, the defect that the refining effect on the CuAlMn shape memory alloy is limited is overcome, and the mechanical property and the low-temperature damping performance of the existing CuAlMn shape memory alloy are improved remarkably at the same time.

The invention relates to the technical field of multiphase ceramics, in particular to a high-entropy diboride-boron carbide multiphase ceramic as well as a preparation method and application thereof. The composite ceramic comprises a mixture of the following molar components: 5-9 kinds of transition metal carbides (titanium carbide, zirconium carbide, hafnium carbide, niobium carbide, tantalum carbide, vanadium carbide, chromium carbide, molybdenum carbide and tungsten carbide) each with the amount of 0-1 part, and boron powder with the amount of 32-60 parts. The transition metal carbides are powder, the purity is greater than 98%, and the particle size is 0.5-3 microns. The purity of the boron powder is greater than 95%, and the particle size is 0.5-3 microns. The Vickers hardness Hv5 of the high-entropy diboride-boron carbide composite ceramic is greater than or equal to 20 GPa, the bending strength is greater than or equal to 420 MPa, and the fracture toughness is greater than or equal to 5.0 MPa*m<1 / 2>. According to the invention, rapid in-situ synthesis preparation of the light, high-toughness and high-entropy diboride-boron carbide composite ceramic is realized, and the sintering temperature is low, so that the high-entropy diboride-boron carbide multiphase ceramic has a wide application prospect in the fields of ultrahigh-temperature materials, superhard materials, ceramic cutters and the like.

The invention discloses a reciprocating twisting and upsetting isometric angle forming method for preparing an ultra-fine grain material. Based on a multi-station forming hydraulic machine, a combinedfemale die is adopted as the die, wherein an upper die and a lower die of the combined female die are split. An upper sliding block in the multi-station forming hydraulic machine is used for providing die combining force needed by the combined female die, and a die inner cavity of the combined female die is formed by sequentially connecting a left-side extruding channel, a twisting channel, a right-side extruding channel and an isometric angle extruding channel. Due to the fact that a left-side hydraulic cylinder located at the inlet end of the left-side extruding channel and a right-side hydraulic cylinder located at the inlet end of the isometric angle extruding channel are used for providing extruding force and back pressure force in turns. The right-side hydraulic cylinder is arrangedon an arc sliding rail, the position of the right-side hydraulic cylinder in the arc sliding rail is adjusted so that the set angle of the isometric angle extruding channel can be obtained. By meansof the reciprocating twisting and upsetting isometric angle forming method, the grain structure of the material can be refined to the ultra-fine grain level, the material strength and plasticity are obviously improved, the application range is wide, operation is easy and convenient, and industrial application is easy to achieve.

The invention provides a high-intensity and high-plasticity magnesium alloy composite plate and a preparation method thereof. The magnesium alloy plate is prepared from Mg, Al, Zn, Mn, Si, Cu and Fe,and is excellent in mechanical properties such as intensity, plasticity and the like; the room temperature ductility of the plate is not less than 21 percent; the surface vickers microhardness is notless than 126 Hv; and the tensile strength is not less than 270.9 MPa. According to the method provided by the invention, a product with good mechanical properties is finally achieved by steps of stirring and friction processing treatment, surface peening and the like. The raw materials of the composite plate adopt magnesium alloy industry-level rolled plates; the production process is relativelysimple, and the overall performance of the plate is obviously improved.