809 results about "Molten bath" patented technology

Scanning Laser Epitaxy (SLE) is a layer-by-layer additive manufacturing process that allows for the fabrication of three-dimensional objects with specified microstructure through the controlled melting and re-solidification of a metal powders placed atop a base substrate. SLE can be used to repair single crystal (SX) turbine airfoils, for example, as well as the manufacture functionally graded turbine components. The SLE process is capable of creating equiaxed, directionally solidified, and SX structures. Real-time feedback control schemes based upon an offline model can be used both to create specified defect free microstructures and to improve the repeatability of the process. Control schemes can be used based upon temperature data feedback provided at high frame rate by a thermal imaging camera as well as a melt-pool viewing video microscope. A real-time control scheme can deliver the capability of creating engine ready net shape turbine components from raw powder material.

The invention provides a long glass fiber reinforced polypropylene material and a preparation method thereof. The mass ratio of the material components is: 35 percent to 55 percent of polypropylene, 35 percent to 50 percent of long glass fibers, 0.3 percent to 0.8 percent of coupling agents, 5 percent to 10 percent of compatilizers, 2 percent 4 percent of flow modifiers, 0.3 percent to 0.6 percent of antioxidants and 1 percent to 2 percent of lubricants. The invention has the process that the polypropylene, the flow modifiers, the compatilizers, the antioxidants and the lubricants are mixed firstly, then the mixture is added into a double screw extruder, and the processing temperature is 180 DEG C to 230 DEG C; a molten bath is formed by extruding melts from the extruding die of the extruder; the continuous long glass fibers are preheated for drying, and the surfaces of the long glass fibers are processed; later, a soakage device is introduced to lead a plurality of strands of the long glass fibers into the molten bath so that the long glass fibers are completely soaked and then is bundled to be packaged, and finally, the long glass fibers are discharged from a bell-mouthed die head outlet to be cooled and cut into granules to obtain the long glass fiber reinforced polypropylene granule materials. The invention has simple and practical process and favorable product performance.

The invention relates to a manufacturing method of thin strip continuously cast and cold rolled non-oriented electrical steel, comprising the following steps: smelting molten steel the temperature and components of which meet the requirements, casting the molten steel into a molten bath formed by a pair of water-cooling crystallizing rolls rotating at high speed, then cooling for the second time, hot rolling, cooling for the third time, coiling, cooling to room temperature, pickling, cold rolling, and finally annealing to obtain the cold rolled non-oriented silicon steel sheet with high magnetic induction and low iron loss. In the invention, the thin strip continuous casting process can eliminate the hot rolling thinning procedure in the traditional process, thus avoiding quality defect caused by the improper hot rolling process, simultaneously reducing the equipment loss, and reducing the maintenance and overhaul costs of equipment; the solidification process is controlled to improve the medium axialite proportion of the casting strip, thus improving the corrugation defect of the product in the cold rolling process; and the range of components of the non-oriented silicon steel smelting is widened by the characteristic of quick solidification of the continuously cast thin strip, and the smelting cost is lowered. The invention has the advantages of short process flow, low energy consumption, high efficiency, low production cost, simple manufacturing method and obvious energy saving and consumption reducing effects.

The invention discloses a flash smelting method of iron. A flash smelting furnace comprises a reaction tower, a furnace charge nozzle, a molten bath and a flue, wherein a reaction space is limited in the reaction tower, the furnace charge nozzle is arranged at the top of the reaction tower, the molten bath is arranged on the lower portion of the reaction tower and used for containing melt fallen from the space of the reaction tower after reaction and for a subsequent reduction reaction of the melt, and the flue is communicated with the reaction tower through the molten bath and used for discharging flue gas generated during the reaction. The flash smelting furnace in the embodiment can be effectively used for flash smelting of the iron.

The invention discloses a method of shape and property control of electric arc additive manufacturing through assistance of ultrasonic vibration. In the process of electric arc additive manufacturing, non-contact ultrasonic vibration is applied to molten baths synchronously, grains in the molten baths are crushed, growth of the grains is restrained, and refinement of the grains is achieved. Meanwhile, by effectively utilizing residual heat of a formed part, the effect that a material in the position where a tool bit makes contact with the surface of a cladding layer is in a softened state is guaranteed, by applying ultrasonic vibration to the tool bit, the tool bit impacts the surface of the cladding layer at a high frequency, and finishing processing and surface reinforcing treatment are conducted on the surface, so that the dimension precision of the cladding layer is improved, the residual stress of the cladding layer is reduced, the surface grains are refined, and accordingly the purpose of shape and property control of electric arc additive manufacturing is achieved. According to the method, the roughening effect of the residual heat accumulation amount to the part grains and severe influences of warping deformation are reduced and even avoided, the service cycle of the tool bit is prolonged, and subsequent machining treatment of parts is reduced. The effective method is provided for shape and property control of the electric arc additive manufacturing technology.

A method is provided for measuring a temperature of a molten metal bath by an optical fiber surrounded by a cover. The optical fiber is immersed in the molten bath, and the radiation absorbed by the optical fiber in the molten bath is fed to a detector, wherein the optical fiber is heated when immersed in the molten bath. The heating curve of the optical fiber has at least one point P(t0, T0), wherein the increase ΔT1 in the temperature T of the optical fiber over the time Δt in a first time interval t0−Δt up to the temperature T0 is smaller than the increase ΔT2 in the temperature of the optical fiber over the time Δt in an immediately following second time interval t0+Δt.

The invention discloses weathering steel, which comprises the following chemical compositions in percentage by weight: 0.06 to 0.12 percent of C, 0.20 to 0.40 percent of Si, less than or equal to 1.6 percent of Mn, 0.08 to 0.22 percent of P, less than or equal to 0.008 percent of S, 0.01 to 0.06 percent of Al, 0.20 to 0.80 percent of Cu, 0.40 to 0.75 percent of Cr, 0.12 to 0.40 percent of Ni, 0.001 to 0.006 percent of Ca and the balance of iron and inevitable impurity elements. The weathering steel is manufactured by a thin strip continuous casting process. The manufacturing process comprises the following steps of: performing deep desulfurization on molten steel, performing composite blowing on the top and bottom of a converter, performing RH vacuum circular degassing process, and simultaneously performing calcium treatment; performing twin-roll continuous casting, and making the temperature of the molten steel in a molten bath not lower than 1,535DEG C; controlling rolling in the reduction ratio of not less than 30 percent; controlling cooling at the speed 30 to 50 DEG C / s; and coiling at the temperature of between 600 and 650 DEG C. The weathering steel of which the texture is acicular ferrite has good weatherability and can be widely applied to structural materials.

The invention discloses a laser-CMT welding aluminum alloy additive manufacturing method and a forming system. A laser and an electric arc are adopted as a composite heat source, the cold metal short circuiting transfer manner is adopted, and additive manufacturing forming for an aluminum alloy component is achieved. According to the provided laser-CMT welding additive manufacturing method, the problems that in the process of aluminum alloy component manufacturing through laser additive, the required laser power is high, and forming is difficult are solved, the problems that in the traditional process of aluminum alloy manufacturing through electric arc additive, the heat input amount is large, deformation is serious, and a molten bath is prone to overflowing or webbing are solved, and the problem that in the process of aluminum alloy manufacturing through CMT welding additive, incomplete fusion or slag inclusion or the like is likely to happen is solved; and the additive manufacturing method based on the laser-electric arc composite heat source principle is provided for additive manufacturing forming for the aluminum alloy component.

The invention discloses a quasi-continuous laser metal 3D printing method capable of realizing regulation of nickel base alloy crystallographic texture. Laser output is set as a quasi-continuous lasermode, and then a laser metal 3D printing technical window is preliminarily optimized. The temperature field of a molten bath under the preliminarily optimized parameter is calculated by using a finite element heat transfer model; the temperature gradient G and the cooling rate xi of the moving boundary of the molten bath during closing of laser in a single pulse period are extracted, and the growth length L of a single pulse internal columnar dendrite is worked out according to a structure growth theoretical model; the laser parameter is optimized according to the matching rule that the ratioof the scanning speed V to pulse frequency f is 0.5-0.8L, and finally 3D printing forming is conducted according to the optimized parameter, so that a formed part with the consistent crystallographicorientation height is obtained. By regulating the heat source output mode, an effective remelting mechanism for mixed crystal or isometric crystal is introduced in the scanning direction, all columnar dendrite growth is obtained, and the consistency of grain orientation is remarkably improved.

The invention provides a device and method for gradient materials additive manufacturing by using two-wire twin-electrode tungsten inert gas arc. A first partial tungsten electrode and a second partial tungsten electrode are installed below a two-tungsten-electrode argon arc additional material manufacturing gun of the device, and are vertically arranged above a base plate. A first wire guide nozzle and a second wire guide nozzle are arranged in front of the two-tungsten-electrode argon arc additional material manufacturing gun. In the deposition process, two metal wires of dissimilar compositions are conveyed to a melting bath at the same time, the composition and performance of a deposition bead are controlled by adjusting the feeding proportion of the metal wires, and thus manufacturingof the gradient material arc additional material is achieved. It is ensured that excellent forming can still be achieved in the deposition process with large current and high wire feeding speed, thecomposition of the prepared gradient material formed part can be continuously transited from the composition of one metal wire to the composition of the other metal wire without replacement of the welding wires, and the deposition efficiency is up to 330 cm<3> / h; and in addition, the deposition bead is more uniform in composition, and the relative error between the components of the deposition bead and target set compositions is smaller than 10%.

The invention provides a welding quality monitoring system and method. The welding quality monitoring system comprises a welding gun, a thermal infrared imager, an image capture card and an image processing computer. The welding gun is used for welding welding spots. The thermal infrared imager is used for recording molten bath infrared thermal imaging data of the welding spots. The image capture card is used for collecting the molten bath infrared thermal imaging data and sending the molten bath infrared thermal imaging data to the image processing computer. The image processing computer is used for analyzing the molten bath infrared thermal imaging data to obtain welding parameters, comparing the welding parameters with preset welding standards and obtaining a welding spot quality estimation result. In this way, by the adoption of the welding quality monitoring system and method, online monitoring of automatic welding quality can be achieved, the monitoring efficiency and monitoring quality are improved, and the missing inspection rate is reduced.

The invention discloses an auxiliary wire filling GMA additive manufacturing device and method for gradient material manufacturing. The device comprises a GMAW arc welding power source, a wire feeder, a GMAW welding gun, two wire guiding nozzles and two auxiliary wire filling wire feeders. The wire feeder is used for conveying a consumable electrode welding wire, and a feeding hose of the wire feeder is connected with the GMAW welding gun. The GMAW welding gun is vertically arranged over a molten bath and used for guiding the consumable electrode welding wire into the molten bath, and the generated arc is located between the consumable electrode welding wire and the molten bath. The two auxiliary wire filling wire feeders are used for conveying homogenous filling welding wires and heterogeneous filling welding wires, and feeding hoses of the two auxiliary filling wire feeders are connected with the two wire guiding nozzles correspondingly. The two wire guiding nozzles are fixed to the front end of the GMAW welding gun and used for guiding the homogenous filling welding wires and the heterogeneous filling welding wires to be fed into the molten bath. The auxiliary wire filling GMA additive manufacturing device and method solve the problem that in the traditional GMA additive manufacturing process, heat accumulation of a formed part is serious, and continuous component adjustment cannot be achieved.

The invention relates to a composite bed reactor and a method for combined production of calcium carbide, gas and tar, and belongs to the field of calcium carbide production. The reactor comprises a hopper, a brake bunker, a moving bed preheating chamber, a tar collector, a gas outlet, a distributing device, an oxygen heat reaction chamber, oxygen spraying burners, a product molten pool and a product outlet, and the hopper is connected with the moving bed preheating chamber by the brake bunker, and the top side surface of the moving bed preheating chamber is provided with the tar collector, and the tar collector is provided with a gas outlet, and the moving bed preheating chamber bottom is provided with a distributing device, and the moving bed preheating chamber is communicated with an oxygen heat reaction chamber by a distributing device, and the oxygen heat reaction chamber bottom is connected with a product molten pool, and the upper portion of the connection between the oxygen heat reaction chamber and the product molten pool is provided with the oxygen spraying burner, and the middle bottom of the product molten pool is provided with a product outlet. The reactor of the invention has the advantages of simple structure and high efficiency, and large scale production is easy to realize, and the raw material is pelleted by powder form carbonaceous raw material and powder form calcium containing raw material, and the contact surface between raw materials is large, the reaction rate is fast, and reactor is convenient for reusing calcium carbide slags.

This invention relates to a high strength and anti-heat Mg alloy and its preparation method, in which, the composition and its weight percentage of the Mg alloy is: 3-12%Y, 2-6%Sm, 0.35-0.8% Zr, the gross volume of impurities of Si, Fe, Cu and Ni is less than 0.02% and Mg for the rest, in smelting, Y, Sm and Zr are added into a Mg molten bath in the way of intermediate alloy of Mg-Y, Mg-Sm and Mg-Zr to be smelted to get the Mg alloy to be treated in solid solution under 500-550deg.C for 6-12 h, after that, it is undergone for 6-50 h aging treatment under 175-250deg.C to increase its strength.

The invention discloses a low-hydrogen basic electrode for welding FV520 (B) stainless steel, comprising a core wire and an electrod covering, wherein the electrode covering comprises the following materials in weight percentage: 35%-45% of marble, 18%-26% of fluorite, 6%-9% of quartz, 3%-6% of zircon sand, 6%-12% of rutile, 1%-3% of ferrosilicon, 6%-10% of ferrotitanium, 5%-11% of low-carbon ferromanganese, 1%-3% of rare-earth ferrosilicon and 0.5%-1.5% of sodium carbonate, and the sum of the weight percentages of the components is 100%. Compared with the traditional special imported electrode for the FV520 (B) stainless steel, the electrode made of the electrode covering has the advantages of favorable arc stabilization performance, good fluidity of a molten bath, less splash and dust, easier slag removal after welding, uniform slag coverage, and delicate and attractive welding joint formation. The content of diffusible hydrogen generated by using the developed electrode for depositing metal is effectively controlled and meets the requirements of low-carbon contents.

A zinc leaching slag treatment method comprises the following steps: 1) The dried zinc leaching slag is evenly mixed with coke powder, and then the mixture is added to a volatilization kiln through a feeding scraper-trough conveyer at the tail of the kiln; 2) under the high-temperature condition of the volatilization kiln, the mixture generates kiln slag and smoke, valuable metals in the zinc leaching slag are deoxidize, as a result, lead and zinc steam is generated and gathered in the smoke, and gold, silver and copper enters to the kiln slag; 3) the kiln slag is delivered to a smelting furnace, furnace burden is added from the top of the smelting furnace, oxygen-enriched air is blown through an oxygen lance, the furnace hearth is stirred, the smelting temperature of the smelting furnace and the ratio of oxygen quantity to kiln slag dry measure are controlled, and slagging smelting is completed; 4) after the slagging smelting carried out in step 3), the valuable metals gold, silver and copper in the kiln slag are gathered in matte, the generated lead steam is gathered in smoke, and the kiln slag is cooled gradually. According to the zinc leaching slag treatment method, the technological process is short, the energy consumption is low, the cost is low, and the valuable metal recovery rate is high.

The invention discloses a molten bath monitoring device of an additional material manufacturing process based on multiband coupling and a method. The device is composed of a processing unit, a signalcollecting unit, a data processing unit, and a data storage unit. By means of a multi-wavelength refracting-diffracting mixed f-theta focus lens, a dichroscope and other optical elements, three lightpaths (laser processing light path, laser lighting path and a bath image information collecting light path) at different wave sections can be coaxially coupled at outside of a shaping cavity, thus therapidly moved small bath can be tracked and collected in real time; besides, the bath image and the characteristic information can be rapidly calculated and stored in multiple grades through the dataprocessing unit and the data storage unit; the long-time monitoring of the bath during the fusion additional material manufacturing process of a powder bed is realized. The device can realize the high-precision and full-flow monitoring during the long time working process of the fusion additional material manufacturing of the powder bed; the technical condition is created for the evaluation of the additional material manufacturing and shaping quality and regulation of technical parameters.

The invention discloses a production method of a composite coating and particularly discloses a method for preparing an alloy-ceramic composite coating through plasma spray-welding. The specific process comprises steps as follows: firstly, the surface of a matrix, alloy powder and ceramic particles are pretreated; then the surface of the matrix is clad with the alloy powder and the ceramic particles by the aid of a designed plasma spray-welding torch, so that a metal-ceramic composite material strengthened layer is formed; when plasma spray-welding is performed, the alloy powder is directly conveyed into an electric arc of a plasma transferred arc and is quickly molten into the liquid state in the electric arc to fall onto the surface of the matrix to form a molten bath; and the ceramic particles are conveyed to the outsides of plasma nozzles and fall into the molten bath on the outside of an arc column of the plasma transferred arc. With the method, the ceramic particles and the arc column fall into the molten bath formed by the molten alloy powder in the state that a certain distance is kept, so that adverse effects such as oxidation, decarburization and the like caused by the high temperature of the electric arc on the ceramic particles can be effectively avoided.

The invention discloses an electric arc additive manufacturing method and device with an electromagnetic field and forced processing being combined for assisting. Molten bath heat and mass transfer ischanged by additionally arranging the magnetic field, the stress distribution state of formed workpieces is further changed through plastic forced processing, and thus the fused deposition process can be changed. The method includes the whole forming processes of molten bath solidification and crystallization, solid-state phase transformation to recrystallization and plastic deformation. Variousphysical fields of electromagnetism, heat and force are used for acting on the workpiece forming process, the metallurgy, microstructure and stress-strain distribution state of formed parts are controlled, and hence the properties of the formed parts can be improved. Under the electromagnetic force action on an electric arc fused deposition molten bath by the magnetic field, the molten bath is stirred, and therefore crystal particles are refined, the forming structure is changed and the defects are overcome. A forced processing device followed by a welding gun is used for conducting plastic forced processing on welding beads, residual stresses of the welding beads are reduced, the crystal particles are refined, and the properties like fatigue resistance and crack resistance of the formed parts are improved.

An arc-ultrasonic welding method for Ti alloy features that an arc-ultrasonic exciting source using electric arc as heat generater and ultrasonic emitter is parallelly connected with the conventional power supply used for arc welding. The ultrasonic waves can act on the molten bath on the workpiece to be welded to improve the smelting and crystallizing procedure of Ti alloy for finer crystal grains and higher welding strength and fatigue resistance.

The invention discloses an efficient butt-joint laser welding method for a laminated duplex-metal composite material. The efficient butt-joint laser welding method comprises the steps that a base layer retaining layer is arranged at the portion, close to one side of a composite layer, of a base layer to form an I-type groove; the characteristic that in the laser penetration-type welding process, liquid metal at the upper portion and liquid metal at the lower portion inside a molten bath conduct Marangoni convection at the respective positions under the action of metal vapor friction and the temperature gradient, and little convection exchange happens between the liquid metal at the upper portion and liquid metal at the lower portion is used for being matched with the laminated characteristic of the laminated duplex-metal composite material, and the performance characteristics of two metal materials in a weld joint are ensured. The efficient butt-joint laser welding method has the advantages that one-time butt-joint welding forming of metal of the composite layer and some metal of the base layer is achieved, the working procedures of sealing and welding of a transition layer during a traditional composite board or composite pipe butt-joint welding are omitted, and the depth and the width of the remaining groove in the base layer are reduced, in other word, the welding amount of the base layer is reduced.

The invention discloses a method for preparing a heat-resistant antifriction alloy coating on the surface of a continuous casting roller. The method is characterized by comprising the following steps of: (1) pretreating the surface of the continuous casting roller; (2) selecting alloy powder, and adjusting an automatic powder feeding device; (3) adjusting light beams; (4) selecting a DL-HL-T5000 type CO2 laser and an operating platform as a SIMENS numerical control laser machine, feeding the alloy powder into a laser molten bath automatically by using a synchronous powder feeding device, focusing the laser beams at high power, and feeding by using an automatic powder feeding head along a rotating wheel shaft to form a uniform compact laser cladding layer on the surface of the continuous casting roller; and (5) cladding, and then performing flaw detection. By the laser cladding method, the alloy powder with heat resistance and friction resistance is uniformly cladded on the surface of the continuous casting roller to form a uniform compact metallurgical bonding coating, and the cladding layer is firmly combined with a substrate in a metallurgical manner and cannot be stripped.

The present invention is oxygen-enriched air copper refining process in a converting furnace. The process features the oxygen-enriched air converting in the condition of oxygen pressure higher than the inner layer air pressure and common air converting in other condition, the control of the furnace temperature with cold copper material in oxygen-enriched air converting, the control of the coarse copper product quality through stopping addition of cold copper material before finishing the air refining of coarse copper product, and the alternate addition of oxygen-enriched air and common air to avoid generation of foamed slag. The present invention has improved operation environment, raised converting rate, lowered fuel consumption and raised economic benefit.

A molten bath-based direct smelting process for producing ferrous metal from a ferrous feed material is disclosed. The process is characterised by injecting pro-heated air downwardly into metallurgical vessel at an angle of 20 to 90° C. relative to a horizontal axis and at a temperature of 800-1400 ° C. and at a velocity of 200-600 m / s via at least one lance (27) . This step forces molten material in the region of a lower end of the lance away from the lance and forming a “free”space around the lower end of the lance that has a concentration of molten material that is lower than the molten material concentration in the raised bath. The process is further characterised in that the lance is located so that: (i) the lance extends into the vessel a distance that is at least the outer diameter of he lover end of the lance; and (ii) the lower end of the lance is at least 3 times the outer diameter of the lower end of the lance above a quiescent surface of the molt bath.

A conticasting technology for thin steel band includes such steps as filling molten steel in the molten bath formed by crystallizing rollers, cooling and slight rolling by crystallizing rollers, blowing gas onto both surfaces of cast band for forced cooling, hot rolling, controlled cooling and winding. Its apparatus is composed of two blowing mechanisms, connecting-rod driver unit and synchronizing unit. Its advantages are high quality of product and high productivity.

The invention discloses a furnace protection process for decarburization converter less slag splashing, belonging to the technical field of combined blowing converter steelmaking. In the process, the technical parameters are controlled as follows: molten iron desiliconized, dephosphorized and desulfurized semi-molten steel is adopted for converter smelting without adding steel scrap; the MgO content in the slag is controlled at 11%+ / -0.5%; the basicity R of slag is controlled to be greater than or equal to 3.5 and less than or equal to 4.0, the TFe content in the slag is less than or equal to25%; lime is adopted for slagging, and the addition of lime is 15-30% of the MgO content in lightly fired dolomite; before slag splashing, the quantity of remaining slag in a molten bath is greater than the critical quantity of remaining slag (45-55kg / t) for ensuring the slag splashing effect; converting end-point control adopts direct tapping without turning down, and slag splashing is directly performed; low lance position slag splashing is adopted, the slag splashing lance position is kept at a basic converting lance position 1.5m initially, and the lance position is lowered to 1.2m after 50% of the slag splashing time; the slag splashing time is 3-5 minutes; and after slag splashing, the quantity of remaining slag is ensured to be 5-15kg / t, and the quantity of remaining slag in the molten bath during slag splashing in the furnace is ensured to be 45-65kg / t. The invention has the advantage of achieving the aim of prolonging the furnace life.

The invention belongs to the field of metallurgy and specifically relates to a one-step lead smelting process and a one-step lead smelting device for waste lead-acid storage battery lead plaster bottom-blowing smelting. A bottom-blowing smelting furnace device is used for performing bath smelting, high-temperature desulphurization and reduction to lead plaster of waste storage batteries, so as to produce water-quenched slag with low lead content, crude lead and flue gas which is suitable for making acid. By using a bottom-blowing furnace and an electric heating fore well to treat the lead plaster of the waste storage batteries to produce crude lead and waste slag, compared with the prior art, the one-step lead smelting process and a one-step lead smelting device for waste lead-acid storage battery lead plaster bottom-blowing smelting has the advantages that the process flow is short, the smelting strength is high, the recovery rate is high, the air-tightness is good, the environmental friendliness is good, the effect of continuous production can be realized, the automation level is high, the production cost is lower, the investment is saved and the like.

The invention discloses a height online monitoring device and closed-loop control method for laser cladding additive forming. The online monitoring device comprises a cladding forming unit and a monitoring control unit. The cladding forming unit comprises a laser device, a cladding head and a matrix. The monitoring control unit comprises an image taking unit, a connecting frame, an image processing unit, a control unit and an execution mechanism unit. In the closed-loop control method, the image taking unit is fixed to laser cladding equipment to move along with a cladding nozzle, images including the cladding nozzle and a molten bath in the cladding additive forming process are acquired in real time, and the image processing unit is utilized for carrying out pixel processing on the images; the outlines of the cladding nozzle and the molten bath in the cladding additive forming process are extracted, and the forming thickness of a single cladding layer is obtained; and the forming height of the formed cladding layer is obtained through layer-by-layer thickness accumulation, the lifting height of a cladding spray head of the next layer is corrected in real time in a self-healing interval, process parameters are optimized in good times, and forming height closed-loop control is achieved.

The invention relates to the technical field of laser machining, in particular to a self-adaptive variable molten bath laser additive material manufacturing technology. The technology comprises the following steps that by means of laser fusing tests, laser powers are adjusted, molten bath widths corresponding to the different laser powers are recorded, and thus a technology database corresponding to molten bath sizes when the different laser powers are different is constructed; and a part three-dimensional model is set up, layering software carries out layering processing on the part three-dimensional model, and plane outline machining information on each layer of a part is obtained. By adjusting the level of the laser powers in real time, the continuous change of the size of a molten bath is achieved, thus, the molten bath can adapt to the change of the wall thickness of the thin-wall part, a variable width molten way is directly formed through one-time scanning instead of multi-pass lap joint, then the variable thickness thin-wall part is formed through layer-by-layer overlapping, and the technology has the beneficial effects that the technological parameter variable is small, response is fast, and the forming efficiency is high.

The invention provides a preparation method of a brake pad. The preparation method comprises the step of carrying out 3D printing on the surface attached with a metal layer, of a steel backing, by virtue of a raw material powder of the brake pad to obtain the brake pad, wherein the components of the metal layer are the same as metal components in the raw material components of the brake pad. According to the preparation method provided by the invention, a high-power electron beam enables the components in the material of the brake pad to be adequately reacted during a 3D printing process, so that the obtained brake pad has high mechanical performance and functional performance; and moreover, the steel backing with the surface attached with the metal layer having the components the same as the metal components in the raw materials of the brake pad is adopted, the metal layer is molten to form a thin molten bath under the scanning of the high-power electron beam during the 3D printing process, and adequate metallurgical bonding is carried out between the molten bath and the raw material powder of the brake pad, so that a wear-resistant layer in the brake pad and the steel backing have a high bonding strength. In addition, the power of the electron beam scans on the raw material powder of the surface of the steel backing during the 3D printing process, without influence on the organizational structure of the interior of the steel backing, thus the own mechanical performance of the steel backing is ensured.