397results about How to "Little thermal impact" patented technology

The invention relates to a preparation process and a device of a nano-particle reinforced bimetal composite, the nano-particle reinforced bimetal composite comprises the following chemical components by weight percent: 6-25% of Cr, 4-18% of Ni, 1.0-4% of Mo, 1.0-1.8% of Si, 1.2-3% of Mn, 0.4-2.2% of B, 0.1-1.2% of MgO, 0.2-2% of CaF2, 0.2-0.7% of C, 0.2-0.8% of Nb, not more than 0.9% of one or the combination of CeO2, Y3O2 and La2O3, 0.0-0.8% of Co, and the balance of Fe, and mixed particles of nano-sized carbides, nitrides, borides or carbonitrides are added in alloy powder. The vacuum induction melting and the cladding processes and equipment are adopted for melting and cladding the mixture on a workpiece, the thickness of a cladding layer is 0.1-25mm, the cladding layer contains 1%-50% of nano-reinforcing particles of one or the combination of the carbides, the nitrides, the borides and silicides, and the cladding layer has special performances of wear resistance, corrosion resistance, electrical conductivity, self-lubrication performance and the like. A coating layer and a base material form the metallurgical bonding, thereby having high bonding strength, overcoming the drawbacks in various coating processes at home and abroad, leading the coating layer to avoid the defects of shrinkage cavities, inclusion, cracking, shedding and the like and having the advantages of high heating temperature, fast speed, high production efficiency, small energy consumption, simple preparation process and low cost.

The invention provides high-entropy alloy powder for 3D (three-dimensional) printing and a method for preparing a high-entropy alloy coating by using the high-entropy alloy powder, and belongs to the technical field of coating preparation. By the high-entropy alloy powder, the wear resistance of the existing powder materials for 3D printing is improved. The high-entropy alloy powder is prepared by using the following ingredients in atomic percentage by weight: 16%-25% of Ni, 16%-25% of Co, 16%-25% of Cr, 16%-25% of Ti and 16%-25% of V. The preparation method comprises the following steps of (1) performing ball-mill mixing on raw materials to obtain mixed powder; (2) grinding and cleaning a matrix; and (3) placing the mixed powder in a powder feeder of 3D printing equipment and sintering the mixed powder on the surface of the matrix to form the high-entropy alloy coating by using selective laser. The NiCoCrTiV coating is prepared by selective laser sintering and has the advantages of high hardness, wear resistance, corrosion resistance and the like. The high-entropy alloy powder for 3D printing and the method for preparing the high-entropy alloy coating by using the high-entropy alloy powder can be widely used in the field of 3D printing.

The invention discloses an aluminum alloy workpiece additive manufacturing method implemented through friction stir welding. On the basis of an existing electric arc additive manufacturing aluminum alloy workpiece, the characteristic that aluminum alloy is soft in property is combined, after an aluminum alloy workpiece is manufactured from electric arc additives layer by layer, friction stir welding intensification treatment is conducted on each layer, and therefore, defects such as pass gaps, interlayer incomplete fusion, air holes and the like can be eliminated through friction stir weldingwhen each layer is manufactured. Compared with the pure electric arc additive manufacturing aluminum alloy workpiece, by means of the method, the structural state of the aluminum alloy workpiece obtained through additive manufacturing can be improved; the grains can be finer; second-phase grains are finer and are distributed more uniformly; and the dislocation density achieved in the aluminum alloy additive manufacturing workpiece is increased. Compared with existing friction stir welding intensification, grain refining and defect elimination are conducted on each layer of the workpiece so that the strength of the whole workpiece can be improved rather than only surface modification, namely surface intensification, is conducted.

The invention relates to an application of a femto-second laser in the treatment of titanium or titanium alloy implanting material surface, belonging to the technical field of application of laser in the material surface treatment, which comprises the following steps: in the air, the femto-second laser pulses are arranged over the massive titanium or titanium alloy materials, are vertically focused on the surface to form a focal point, the laser spot radius of which is 5 Mum, the processing parameters of the femto-second laser are: the PRF is 1 kHz, the single pulse energy is 50 to 300 micro-joules, the pulse width is 50 femto-seconds, the pulse center wavelength is 800 nm, the laser processing line spacing is 10 to 100 Mum, and the laser scanning speed is 0.2 to 1.0mm/s; the polarization direction of the femto-second laser is adjusted to be parallel with the scanning direction of the femto-second laser, the femto-second laser is used to scan the entire surface of the massive titanium or titanium alloy materials which have been immersed in hydroxyl apatite suspension liquid for 5 minutes, so the surface of the titanium or titanium alloy materials present uniform rough peak-like protrusions and a pattern of porous cyclist regular structure, and is loaded with the titanium-based biomedical material of calcium and phosphate salt.

The invention relates to the field of multi-principal element high-entropy alloy materials and in particular relates to a method for preparing a high-entropy alloy coating, belonging to the field of coating preparation. The method for preparing the high-entropy alloy coating comprises the following steps: pretreating a substrate, so that the surface of the substrate is clean and flat; preparing high-entropy alloy powder, uniformly mixing, and adding 3-6wt% of organic solution in the alloy powder; uniformly mixing the organic solution and the high-entropy alloy powder, and preparing into paste; uniformly coating the pasty alloy powder on the treated substrate, wherein the thickness of the coating layer is 0.3-6mm; baking the treated coating layer and substrate in an oven at the temperature of 55-80 DEG C for 20-30 hours; cladding the coating layer on the surface of the substrate through gas tungsten arc welding. According to the method for preparing the high-entropy alloy coating, the high-entropy alloy coating with the thickness of 0.3-6mm can be prepared, a heat affected zone to the substrate in the preparation process is small, and the coating is uniform in distribution and firmly bound to the base material.

The invention relates to a micro-nano-alloy bimetal composite material preparation technique and a device thereof; one of wear-resistant and corrosion-resistant ferrous metal material, non-ferrous metal material and various self-fluxing alloy is prepared into power; then, the powder is added with less than or equal to 0.8% of one or combination in CeO2, Y2O3 and La2O3, 0.3-1.5% of MgO, 0.3-1.8% of CaF2, 0.0-1.5% of B, 0.1-0.8% of Nb, 0.1-1.0% of Ti, 0.1-2.0% of grain refining and recrystallization inhibitor according to the mass percent; or the powder is added with 1-40% of carbide, nitride, micro-nano or nano particles of boride; and the mixture is put into a high-energy stirring ball grinding mill for grinding and ball milling, so that the micro-nano or nano alloy powder can be prepared. A variable frequency induction heating device is adopted for cladding and melting vacuum or inert gas, so that a workpiece can be melted and coated with a micro-nano or nano scale alloy cladding layer which has the grain size of 0.1-35mm and is wear-resistant and corrosion-resistant, and the bimetal composite material can be prepared. The invention overcomes the defects in various coating techniques in China at present, can complete the preparation of the workpiece with the cladding layer having high thickness for once, does not need repeated coating and sintering, has high material utilization rate, low machining allowance and preparation cost, simple preparation technique and high production efficiency.

The invention discloses a roller repair layer and a roller repair method. According to the roller repair layer, a metal layer, a metal-ceramic composite layer and a ceramic layer are thermally sprayed on a base body in sequence from the surface of the base body to the outside. The roller repair method comprises the steps that cleaning, oil removal, rust removal and surface roughening are conducted on the base body, the metal layer, the metal-ceramic composite layer and the ceramic layer are thermally sprayed on the surface of the base body in sequence, and the repair layer is ground until meeting the roller precision. The roller repair layer used for repairing the roller has the advantages of being low in comprehensive cost, easy to manufacture, remarkable in effect, and suitable for large-scale production. The roller repair method can replace a bead weld technology which is widely used at present, and the service life of the roller is remarkably prolonged. Meanwhile, the roller repair method is a green manufacturing technology meeting the national strategy of circular economy and sustainable development, and has wide application prospects and economic benefits.

The invention discloses a split type graphite crucible with a split structure and Y2O3 carbon coating with zero resistance in upper and lower crucible bodies, wherein, a lug boss (12) of the upper crucible body (1) of the split type graphite crucible is arranged inside a concave chamber (23) of the lower crucible body (2), the end surface of the lug boss (12) is in close joint with the bottom of the concave chamber (23) of the lower crucible body (2), a surface of the lug boss (12) of the upper crucible body (1) is in close joint with a concave support surface (22) of the lower crucible body (2); the wall of an inner chamber (14) of the upper crucible body (1) is provided with an A-type inner coating (11) with a thickness of 50-250 um, the bottom of the concave chamber (23) of the lower crucible body (2) is provided with a B-type inner coating (21) with a thickness of 50-250 um. Both the A-type inner coating (11) and the B-type inner coating (21) adopt the spraying method of air plasma to prepare Y2O3 inside the crucible body of the split type graphite crucible so as to form the carbon coating with zero resistance, which effectively stops the chemical reaction between carbon and metal fused mass in the melting process, thereby avoiding carbon pollution.

The invention belongs to the technical field of laser processing and relates to a laser repair welding method for casting flaws of Ti3Al castings. The method is mainly used for repairing the casting flaws of the Ti3Al castings. According to the method, for the Ti3Al castings, Ti2AlNb metal powder with malleability better than that of a base body is selected and used as fusion covering materials, reasonable laser fusion covering technological parameters are adopted, and the casting flaws such as cracks, inclusion, shrinkage porosities and incomplete casting of the Ti3Al castings are repaired. Repaired parts are hardly deformed and are free of the defects of cracks, air holes and incomplete fusion, and high-quality repair welded connectors are formed.

The invention relates to a preparation method of a magnesium alloy corrosion resistant coating. The method is characterized in that spherical aluminum powder or spherical aluminum powder and SiC or Al2O3 powder are adopted, compressed air is used as an air source, and then a coating is prepared by a low-temperature pneumatic spraying method. The adopted powder comprises 100% of aluminum powder or 70-98wt% of aluminum powder and 30-2wt% of hard particles. After-treatment is performed by ceramic shot blasting or a 518 sealant produced by the Beijing Institute of Aeronautical Materials. Compared with the prior art, an aluminum coating prepared by the low-temperature pneumatic spraying method is dense with low porosity and high hardness, has good bonding strength with a base body, and has good corrosion resistance and wear resistance, thereby being a good protection coating for corrosion resistance of magnesium alloy.

The invention discloses a machining method and device for preparing a micro-nano two-dimensional structure on the surface of a workpiece, and belongs to the field of special machining. In the machining process, a laser ablation and electrochemical deposition coupling method is adopted, a laser beam is focused on the surface of a workpiece substrate, the area and path of laser ablation are controlled through a numerical control system, and a micron-grade structure is machined on the surface of the workpiece substrate; and a tool anode keeps being aligned with the ablation area while laser ablation is conducted, and then a nano structure is deposited on the micron-grade structure in the area of the workpiece substrate. In order to restrain an anodic electric field in a top end area of an electrode to the maximum limit, the tool anode penetrates into an insulated glass pipe to achieve side wall insulating. In addition, the temperature of a solution in an irradiation area is increased through the thermal-mechanical effect of laser light, and meanwhile the strong stirring effect is generated to accelerate circular flow updating of deposition liquid and promote quick and efficient growthof the nano structure. The machining method and device are suitable for efficient machining and manufacturing of the micro-nano two-dimensional structure on the surface of a part.

The invention discloses a large-diameter-height-ratio ultra-precision hydrostatic pressure rotary table, belongs to the technical field of ultra-precision manufacturing equipment, and meets the requirements of a large-size ultra-precision lathe used for machining high-precision large-aperture non-spherical optical parts. An upper floating throttler and a lower floating throttler are respectively installed on an upper floating thrust plate and a lower floating thrust plate, the upper floating thrust plate is fixedly connected with a base seat of the rotary table, the lower floating thrust plate is fixedly connected with the base seat of the rotary table through an inner isolation ring and is arranged in an annular groove of the upper floating thrust plate, a radial bearing bush is fixedly connected with the base seat of the rotary table through the lower floating thrust plate and the inner isolation ring, a main shaft is fixedly connected with an upper floating plate, and hydraulic oil is throttled through the throttlers and forms an upper floating liquid hydrostatic pressure thrust oil film between the upper floating plate and the upper floating thrust plate, a lower floating liquid hydrostatic pressure thrust oil film between a lower floating plate and the lower floating thrust plate, and a radial hydrostatic pressure support oil film between the radial bearing bush and the main shaft, so that an axial sealed-type liquid hydrostatic pressure plane round ring thrust bearing and a radial liquid hydrostatic pressure cylindrical bearing are formed. The large-diameter-height-ratio ultra-precision hydrostatic pressure rotary table is applied to the large-size ultra-precision lathe used for machining the high-precision large-aperture non-spherical optical parts.

The invention relates to a two-stage jet nozzles series super-magnetostrictive jet servo valve and an operating method thereof, which belong to the field of a hydraulic servo control technique. The two-stage jet nozzles series super-magnetostrictive jet servo valve provided by the invention comprises an upper end cover (4), a lower end cover (26), a super-magnetostrictive rod (14), an output rod (21), a coil skeleton (8), a polarization magnetic filed generating unit and a driving magnetic field generating unit, wherein the upper end cover (26) is provided with a left valve core installation cavity (45) and a right valve core installation cavity (46) which are symmetrical relative to the axis of the output rod; a group of valve core components are respectively installed in the left valve core installation cavity (45) and the right valve core installation cavity (46); and wedge-shaped amplification mechanisms are formed in the contact positions of the output rod (21) and the left and the right valve core installation cavities. The two-stage jet nozzles series super-magnetostrictive jet servo valve provided by the invention has the advantages of great pressure gain and rapid response, and the driving part has the obvious characteristics of small heat radiation, adjustable polarization magnetic filed, intelligentized effect and the like.

A laser beam is condensed inside a glasses lens (L1) to form a mark (10A). The mark (10A) is formed in a direction almost in parallel to the optical axis of the glasses lens (L1) without obstructing a wearer's view. Positioning is made by allowing the optical reference position (L0) of the glasses lens (L1) to agree with the reference position (T) of a marking device (3), and the glasses lens (L1), after being mounted to the retaing unit (11) of the marking device (3), is positoned based on the optical reference position (L0) of the glasses lens (L1). The glasses lens (L1) is then moved to a marking start position to carry out marking. A pair of hidden marks formed on the glasses lens (L1) are used to adjust the position of the glasses lens (L1), whereby the optical reference position (L0) can be made to agree with the reference position (T) of the marking device (3).

The invention discloses a steel stud and thick aluminum plate frictional stud welding method, which is characterized in that the welding end part of a steel stud is subjected to certain structural design, the steel stud is rotated, is applied with frictional acting force, and is contacted and rubbed with an aluminum plate, and the steel stud is slowly embedded into the thick aluminum plate. Double characteristics of frictional stud welding and threaded connection are realized, so that a welded joint with good performance is manufactured. By the method, steel studs with middle and small diameters are welded with thick aluminum plates. According to the method, the welding strength of the stud welding can be obviously improved, the influence of defects in common welding on the joint quality is reduced, and the service life is greatly prolonged.

The invention belongs to the technical field of laser processing, and relates to a laser manufacturing method for preparing Ni base alloy high-temperature-resistant gradient materials on titanium alloy. The laser manufacturing method is mainly applied to preparation of a titanium alloy high-temperature-resistant layer so as to improve the high temperature resistance property of the titanium alloy. The Ni base with the high temperature resistance property superior to that of the titanium alloy is selected as the high-temperature-resistant layer, and the laser cladding process is used for adding two middle layers namely V-Cr and stainless, so that the Ni base alloy high-temperature-resistant gradient materials are prepared on the titanium alloy. The prepared Ni base alloy high-temperature-resistant layer is good in combination with the titanium alloy base body, and the crack defect on the surface is avoided.

The invention relates to the field of material-surface modification, particularly to a special material for stainless steel substrates composite coating for a thin valve plate and a preparation method of the special material. According to the special material for the stainless steel substrate composite coating for the thin valve plate, stainless steel metal powder is used as a composite coating bonding phase, and the wear resistance is improved through the introduction of hard-phase particles, wherein the stainless steel metal powder is 316L stainless steel powder, the hard-phase particles are WC, and the composite coating comprises the following elements in percentage by weight: 8-9% of Cr, 5-6% of Ni, 1-2% of Mo, 42-43% of W, 2-3% of C, and the balance of Fe. The wear-resistant corrosion-resistant stainless steel substrate composite coating which is disclosed by the invention, is prepared by a method based on cold spraying, the characteristic of low-temperature deposition of the cold spraying is kept, so that undesirable phenomena, such as decomposition, oxidation, phase transition, crystal grain growth and the like, of the coating material, which are caused by high-temperature deposition techniques, such as laser cladding, hot spraying and the like, are avoided.

A thin film high-temperature friction and wear testing device comprises a casing, a driver is arranged in the casing, a moving test sample round disc is arranged on the drive shaft of the driver, a magnetizer, an induction heating coil and an infrared temperature measurement instrument are arranged above the moving test sample round disc in a non-contact manner, a fixed test sample is arranged above the moving test sample round disc in a contact manner and fixed by a fixed test sample fixture, the fixed test sample fixture is mounted on a U shaped cantilever beam, a loading weight is arranged on the fixed test sample fixture, a counter weight is arranged at one end of the U shaped cantilever beam, a linear displacement sensor is symmetrically arranged on the U shaped cantilever beam, a radial feeding system is fixed on the casing, an adjusting rotation shaft is disposed above the radial feeding system, and the U shaped cantilever beam is connected with the adjusting rotation shaft via a connection member. The invention adopts induction heating manner to directly generate heat on a workpiece surface and provide high power density, can achieve the temperature required for testing in short time, and has features of high heating efficiency, high speed, simple heating part and flexible control.