883results about How to "Reduce cooling rate" patented technology

An HVAC system includes a desiccant wheel, wherein the wheel's speed varies with airflow, the wheel is energized for at least a set period at startup, and/or a heat recovery system (e.g., an air-to-air heat exchanger) upstream of the wheel enhances the system's ability to dehumidify air.

The invention discloses a method for brazing or fusion-welding through lasers with ultrasonic waves as auxiliaries, which relates to a welding method. The invention solves problems during processes that the lasers are used to braze or fusion-weld coating metals which has low melting points or dissimilar metals, and the problems are that wetting spreading property is bad, filling amount is not enough, stomatas and solders aren't welded fully and the like. The method of the invention is that during the processes that the lasers are used to braze the coating metals which has the low melting points or the lasers are used to fusion-weld the dissimilar metals, simultaneously, the ultrasonic waves with high-frequency vibrations are applied in welding zones which will be coagulated. The invention has the advantages that the occurrences of air holes can be minimized or avoided, and welding cost can be lowered. Welding solders can flow fully due to the high-frequency vibrations, which is beneficial for the wetting spreads of the welding solders and penetrations of the welding solders to the bottom portion of the welding zones, weld pool width and welding filling amount can be increased, the occurrences of welding defects as non-welding fully, undercuts and the like can be avoided, weld formations can be improved, and weld strength can be increased.

The invention relates to a method for removing aluminum alloy laser welding air holes. The method solves the problem that air hole defects are easily generated in the laser welding and laser-TIG hybrid welding process of aluminum alloy. The method comprises the steps that in the bifocal laser-TIG hybrid welding process of the aluminum alloy, namely, in the aluminum alloy welding process, two beams of lasers (LB1 and LB2) and a TIG electric arc are adopted to jointly act on a welded area, a welding joint bears the combined action of the three heat sources at the same time, and the action modes of the two lasers can be divided into three kinds which comprise a serial distribution mode in the welding direction, a parallel distribution mode perpendicular to the direction of the welding joint and a crossing distribution mode between the serial distribution mode and the parallel distribution mode. According to the welding method, the air hole rate is zero, and air hole defects of the aluminum alloy laser welding are overcome. The method is applied to the field of aluminum alloy laser welding.

This invention concerns with a semiconductor device which is characterized in that the device is provided with a thin film transistor 40 having a polycrystalline semiconductor layer 11, the semiconductor layer 11 including a channel area 22, highly doped drain areas 24, 17 positioned on both sides of the channel area 22 and LDD areas 18a, 18b positioned between the channel area 22 and the highly doped drain areas 24, 17 and lower in dopant density than the highly doped drain areas 24, 17, wherein any diameter of the crystal 14 at least partly existing in the LDD area 18b is larger than the size of other crystals 15.

A compound welding method by using semiconductor laser and CO2 laser comprises the steps: using a semiconductor laser and a CO2 laser to be positioned on one side of a welding line of welded metals in a certain angle, adjusting a focusing position of the CO2 laser to cause a light spot of the CO2 laser to be positioned in the light spot of the semiconductor laser so that the welding direction is consistent with the slow axis direction of the semiconductor laser; using the semiconductor laser to pre-heat the welded metals, heating the part to be welded entering into the light spot of the semiconductor laser to 200-400 DEG C, using the CO2 laser to weld, and performing a post-welding thermal treatment to the welded metals by using the semiconductor laser for the welded parts of the welded metals welded by the welding of the CO2 laser. Due to synchronous pre-heating and post-heating treatments to the welding process, the invention can effectively solve the problem of cold cracking in high-strength steel welding and improve the quality of high-strength steel laser welding.

A technique is provided for forming a crystalline semiconductor film whose orientation is uniform by control of crystal orientation and obtaining a crystalline semiconductor film in which concentration of an impurity is reduced. A configuration of the invention is that a first semiconductor region is formed on a substrate having transparent characteristics of a visible light region, a barrier film is formed over the first semiconductor region, a heat retaining film covering a top and side surfaces of the first semiconductor region is formed over the barrier film, the first semiconductor region is crystallized by scanning a continuous wave laser beam from one edge of the first semiconductor region to the other through the substrate, then the heat retaining film and the barrier film are removed and a second semiconductor region is formed as an active layer of TFT by etching the crystallized first semiconductor region. A pattern of the second semiconductor region formed by etching is formed in a manner that a scanning direction of the laser beam and a channel length direction of the TFT are arranged in almost the same direction in order to smooth drift of carriers.

The invention relates to laser welding and discloses a process method for welding aluminum and aluminum alloy material by laser. The process method comprises steps of: (1) selecting an Nd:YAG laser with high beam quality and high energy density; (2) adopting double-beam laser to weld aluminum and aluminum alloy material, wherein the distance between the two beams is 0.6-1.0 mm, and the energy ratio of the two beams is larger than 1:1; (3) surface treatment of a material to be welded: removing greasy dirt and dust with an organic solvent and removing an oxidation film by mechanical cleaning and/or chemical cleaning; and (4) utilizing the two-beam laser to weld the aluminum and the aluminum alloy material. A needle body, a sleeve and a lead of the invention are manufactured into a whole; therefore, the invention solves adaptability of the laser welding to assembly precision, enhances the stability of welding process and improves welding line quality.

The invention provides tensile strength more than or equal to 780MPa grade hot-rolled dual phase steel. The dual-phase steel comprises the following components in percentage by weight: 0.05-0.08 percent of C, not more than 0.5 percent of S, 0.6-1.2 percent of Mn, less than or equal to 0.015 percent of P, less than or equal to 0.005 percent of S, less than or equal to 0.006 percent of N, 0.01-0.1 percent of Als, 0.05-0.25 percent of Ti, less than or equal to 0.6 percent of Cr or less than or equal to 0.003 percent of B or mixture of Cr and B. The production method by using CSP comprises the following steps: melting and continuously casting to form a slab; heating the continuous cast slab; rolling; carrying out laminar cooling; reeling; and naturally cooling to room temperature. The hot-rolled dual phase steel has the tensile strength of more than or equal to 780MPa, elongation of more than or equal to 15 percent and yield ratio of less than or equal to 0.70. An insulation cover additionally covers the intermediate insulation section, and the band steel cooling speed is reduced, so that generation of pearlite phase change can be effectively prevented. Production of hot-rolled dual phase steel with thickness of 1.2-4.0mm can be realized, the product has the advantages of uniform structure, small molding resilience and no cracking, existing equipment is utilized without adopting ultra fast cooling and other equipment, the production efficiency is high, and the investment is small.

A multi-layer printable thermoplastic film consisting of at least a fluoride polymer film having laminated thereto a polycarbonate film. The printable film is preformed (vacuum molding or thermoforming) and then inserted into a mold which has the configuration of the preformed printable film. A base layer of a thermoplastic such as a polycarbonate resin is injection molded to the exposed surface of the preformed printable film. The molded structure has exterior automotive applications such as lens, etc.

Disclosed is a hardfacing alloy deriving its usefulness from carbides and borides of molybdenum and niobium. The alloy does not rely on chromium as an alloying agent. The hardfacing alloy is capable of being applied to a number of industrial substrates in a crack-free manner, and once applied convert the substrate to a wear- and abrasion-resistant material having an extended service life, even when subjected to harsh wear conditions.

A heat treatment method for strength of 28CrMoNiV steel capable of improving an industrial steam turbine rotor forge piece. The technology comprises the steps that (1), a normalizing and tempering manner is adopted in a preparation heat treatment technology and is used for refining crystalline grains and improving a material internal tissue, residual stress is reduced, and the good foundation is laid for conditioning heat treatment; a ladder heating manner is adopted in heating of normalizing and quenching, and fast heating is avoided; in the rising process, if the heating speed is too high, residual stress obtained after quenching is overlapped, and the problems that the defect of the forge piece is expanded, and even, the forge piece is cracked are possibly caused; in a quenching cooling process, a water quenching oil cooling manner is adopted, the cooling speed of a workpiece in the high-temperature stage is improved, and meanwhile, the cooling speed of a Martensite transition zone is reduced; in the water cooling initial stage, the workpiece vertically moves in a front-and-back manner in water, the quenching effect of the workpiece is fully ensured, and meanwhile, the structural stress and heat stress are reduced; in the medium heat treatment, the tempering temperature is properly reduced, impact toughness is ensured, and meanwhile, the strength of the force piece is improved.

The invention provides an ultra high-temperature resistant nickel-chrome alloy and a manufacturing method thereof, wherein the ultra high-temperature resistant nickel-chrome alloy has a higher meltingpoint, can resist the high temperature higher than 1300 DEG C for a long time and has better tensile strength and yield strength simultaneously. The ultra high-temperature resistant nickel-chrome alloy basically comprises the following components in percentage by weight: 21-25 of Cr, 58-63 of Ni, Al which is not less than 1 and not more than 1.7, Cu which is not less than 0.5 and not more than 1.0, C which is not less than 1 and more than 0.1, Si which is not less than 0.5 and more than 0, Mn which is larger than 0 and not more than 1.0, S which is larger than 0 and less 0.015, and the balance of Fe. The manufacturing method comprises the following steps: mixing the materials according to the alloy components and then smelting; carrying out secondary refining; first heating the mixture to900-1200 DEG C, keeping the temperature for 10-40 minutes, and then forging; cold processing; and water cooling. The invention improves the high-temperature resistant performance, the tensile strength and the yield strength of the alloy, and has better comprehensive benefit. The manufacturing method solves the problems of alloy smelting and heat processing, and improves the product purity.

A rare-earth-iron-boron based alloy powder, in which a heavy rare-earth element such as Dy is present at a higher concentration in a main phase than in a grain boundary phase and which can be sintered easily, and a method of making such an alloy powder are provided. A rare-earth-iron-boron based magnet alloy according to the present invention includes, as a main phase, a plurality of R₂Fe₁₄B type crystals (where R is at least one element selected from the group consisting of the rare-earth elements and yttrium) in which rare-earth-rich phases are dispersed. The main phase includes Dy and/or Tb at a higher concentration than a grain boundary phase does.

Disclosed is a method and system for freezing a biopharmaceutical fluid which is hold in a disposable container. The method includes the steps of arranging the container on the heat transfer surface area, cooling the heat transfer surface area to cool the bottom surface of the container until freezing and forming a layer of ice or an ice block of biopharmaceutical fluid inside the container; dislodging the ice layer or ice block frozen to the container. The steps of cooling the heat transfer surface area and dislodging the ice layer or ice block are repeated until the container is filled with a matrix of frozen biopharmaceutical fluid and liquid biopharmaceutical fluid, the liquid biopharmaceutical fluid occupying interstitial passages between ice layers or ice blocks of biopharmaceutical fluid. The cooling is then maintained until the freezing of the entire biopharmaceutical fluid held in the container.

The invention belongs to the technical field of laser added material manufacturing, and relates to a method for preparing TiAl+Ti2AlNb composite materials by laser melting deposition. The laser melting deposition method is adopted to form the TiAl+Ti2AlNb composite materials; and the feeding quantity of Ti2AlNb is adjusted to achieve a pinning effect in composite material structures to improve overall plasticity of the materials. Meanwhile, circular samples are formed, and scanning paths are changed to concentric arcs to prevent the tensile stress of linear scanning paths of rectangular samples; and concentric circle openings on each layer are converted by 60-90 degrees, that is, the positions of scanning initial points on each layer are changed, so that the thermal stress concentration isreduced to prevent cracks. The heat input quantity in the forming process is controlled, and the substrate preheating temperature in the forming process is adjusted to slow down the formed metal solidification speed and cooling speed, so that the stress is released for a longer time.

The invention provides a wall maintaining method based on automatic temperature measurement and temperature stress reduction, which comprises the following steps: before casting the concrete wall, mounting temperature sensors of a wireless thermodetector at positions with different heights and different thicknesses inside the to-be-cast concrete wall; after casting the concrete, reading the temperature in the concrete through the temperature sensors; based on the read temperature, carrying out the following operations: spraying water to the outer side of the template during the temperature rising process as heat is released due to hydration heat of cement at the early stage of the concrete wall; when the temperature inside the wall is raised to a peak value, stopping spraying, covering thin film on the outer side of the concrete wall to keep temperature of the wall, and delaying the rate of temperature fall of the wall. The structure is simple, and easy to operate. The method can actively protect the wall from temperature crack at the early stage by virtue of spraying the concrete and covering the thin film on the surface to control the temperature inside the concrete, and meanwhile improve the construction quality of the wall.

The invention provides a gas protection welding method of 1000 MPa-level engineering machine high-strength steel thick plates. Welding base materials are Rm1000-1100 MPa engineering machine quenched and tempered steel plates in equal-thickness flat plate butt joint, a groove is a double-side V-shaped asymmetric groove, the angle of the groove is 60 degrees, a truncated edge is 2-3 mm long, and an assembly gap is 2 mm wide. According to welding materials, bottoming welding wires are 700 MPa-level solid-core gas-protected welding wires with the diameter of 1.2 mm, and filling and surface covering welding wires are 1000 MPa-level solid-core gas-protected welding wires with the diameter of 1.2 mm. The welding method includes the welding steps that bottoming welding is conducted, filling welding is conducted, surface covering welding is conducted, slow cooling is conducted after welding, and joint areas in the range of 300 mm on the two sides of a weld joint are covered with asbestos cloth. Preheating is not needed, after-heating is not conducted, strength and toughness of a joint are ensured, the variety of welding gas and replacement frequency of equipment and the welding wires are reduced, the high-strength advantage of high-strength steel can be fully achieved, and maneuverability is high.

The invention provides a surfacing electrode containing rare earths with a welding core but without a coating. The composition of the welding core is 3.2% to 6.5% of C, 0.4% to 2.5% of Si, 0.4% to 2.0% of Mn, 0.01% to 1.0% of Re, 10% to 35% of Cr, 0.0% to 2.0% of Mo, 0.0% to 2.8% of Ni, 0.0% to 2.5% of W, 0.0% to 1.5% of V, 0.0% to 1.0% of Ti, 0.0% to 1.5% of Nb, 0.0% to 0.5% of Cu, 0.0% to 0.6% of Al, not more than 0.08% of S, not more than 0.08% of P, not more than 0.08% of , not more than 0.08% of <N>, and 59.64% to 85.99% of Fe. The welding rod is suitable for the build-up welding of burning single-roll crusher hammer; the hardness HRC of the build-up welding layer at room temperature is not less than 50 and crack is allowable for build-up welding layer.

The invention belongs to the field of the metallurgy technology and material science, and aims at providing a laser welding process method of brittle high silicon steel. Quick welding of strip tension rolling in the rolling preparation process of a high silicon steel thin strip is met. According to the mass ratio, an adopted alloy is prepared from 93%-96.5% of Fe and 3.5%-7% of Si; and the thickness ranges from 0.1 mm to 3.5 mm. According to the method, laser welding and a supplementary heat source are combined, and double-face or single-face welding is adopted; preheating carried out before welding is utilized for controlling the temperature rise speed, and heat preservation during welding and heat preservation carried out after welding are utilized for slow cooling to control the temperature reduction speed; and the temperature gradient and welding stress in the weld joint cooling process are reduced, and welding forming of the brittle high silicon steel is achieved. By means of the adoption of the method, cracks generated by the too high welding stress of the brittle high silicon steel can be avoided well, and the yield and the mechanical performance of the brittle high silicon steel are increased.

The invention relates to a laser-electric arc composite heat source high-speed welding method of ultrahigh strength steel, belonging to the technical field of high-strength steel welding. The traditional laser-electric arc composite heat source high-speed welding method of the high-strength or ultrahigh strength steel has overhigh welding linear energy due to low welding speed and large energy input so as to cause the deformation of a welding workpiece; in addition, chevilled silk spacing is overlarge, and stabilization action realized by a laser is reduced because the laser is adopted firstly and the electric arc is adopted subsequently so that a welding process is unstable and easy to generate splashing. The invention adopts laser-electric arc composite heat source welding; the welding workpiece is the high-strength steel or the ultrahigh strength steel; an electric arc welding gun is used for welding firstly and a laser nozzle is used for welding subsequently during welding; the current of electric arc welding is 140-180A, and the voltage of the electric arc welding is 23-25V; an included angle theta between the electric arc welding gun and the surface of the workpiece is 60-65 degrees; the laser power is 3-5kW; the welding speed v is 1-3m/minute; and the chevilled silk spacing h between a laser beam and a welding stick is determined within a range of 1-3mm. The invention realizes the welding of the ultrahigh strength steel without preheating, cold cracks or deformation.

A surface region of a semiconductor material on a surface of a semiconductor device is doped during its manufacture, by coating the surface region of the semiconductor material with a dielectric material surface layer and locally heating the surface of the semiconductor material in an area to be doped to locally melt the semiconductor material with the melting being performed in the presence of a dopant source. The heating is performed in a controlled manner such that a region of the surface of the semiconductor material in the area to be doped is maintained in a molten state without refreezing for a period of time greater than one microsecond and the dopant from the dopant source is absorbed into the molten semiconductor. The semiconductor device includes a semiconductor material structure in which a junction is formed and may incorporate a multi-layer anti-reflection coating. The anti-reflection coating is located on a light receiving surface of the semiconductor material structure and comprises a thin layer of thermal expansion mismatch correction material having a thermal expansion coefficient less than or equal to that of the semiconductor material, to provide thermal expansion coefficient mismatch correction. An anti-reflection layer is provided having a refractive index and thickness selected to match the semiconductor material structure so as to give good overall antireflection properties to the solar cell.

The invention relates to a hot-working die steel plate. The steel plate is composed of, by mass, 0.45-0.55% of C, 0.20-0.80% of Si, 0.50-0.80% of Mn, 3.00-3.50% of Cr, 1.30-1.80% of Mo, 0.05-0.20% of V, 0.02-0.10% of Nb, 0.01-0.04% of Als, 0-0.015% of P, 0-0.005% of S and the balance Fe and inevitable impurities. The technological process comprises the steps of steel making, casting of steel ingots, heating, blooming, hydrogen diffusion, heating, steel rolling and heat treatment. A brand-new production method of the hot-working die steel plate is provided. The steel plate has the good comprehensive mechanical performance, and the preparation method of the steel plate is good in production stability and concise in technological process and facilitates batch production of hot-working die steel.

An HVAC system includes a desiccant wheel, wherein the wheel's speed varies with airflow, the wheel is energized for at least a set period at startup, and/or a heat recovery system (e.g., an air-to-air heat exchanger) upstream of the wheel enhances the system's ability to dehumidify air.

The invention discloses a smoke discharge continuous monitoring method, comprising the steps that: a, sampling device works to continuously sample the smoke in a smoke pipeline; b, the valve at the inlet of the gas chamber is opened to transmit the sampled smoke into the gas chamber; c, a measurer measures the parameters of the smoke in the gas chamber, and in power off, the valve at the inlet of the gas chamber is closed, the clean gas without corrosive components and much water is exchanged with the residue gas in the gas chamber. The invention further discloses a smoke discharge continuous monitoring system. The invention has the advantages that the smoke discharge continuous monitoring method and the smoke discharge continuous monitoring system can prevent corroding and damage the gas chamber, polluting the gas chamber and blocking the gas pipeline, having simple structure, maintainability, stability and wide application in smoke discharge continuous monitoring.

The invention provides a copper-steel bimetal casting improved technology. Copper or copper alloy in a certain thickness is directly cast on a steel base body through a static cast type casting method, and the main technical process comprises the steps of: cleaning a steel billet, heating the steel billet and spraying a borax solution on the heated steel billet, combining the cast, heating and keeping the heat, melting and pouring the copper or copper alloy, performing ultrasonic vibration on the steel billet, and keeping the high temperature of the cast. Through the copper-steel bimetal casting improved technology provided by the invention, the ultrasonic vibration and stirring step is added on the basis of the static embedding process technology, a copper or copper alloy layer in a certain thickness and without segregation can be obtained by casting on steel billets in various types and various sizes, and good metallurgical bonding can be realized between the copper or copper alloy layer of the obtained cast and the steel billet.

The invention discloses an ultrasonic coaxial auxiliary laser welding method for a plate heat exchanger, before a plate sheet of the plate heat exchanger is welded, a self-designed laser welding auxiliary process device is used for clamping the plate sheet of the heat exchanger, in a process of performing the laser welding, high frequency ultrasonic vibration is applied, the ultrasonic vibration and laser beams are applied in a coaxial manner, during laser welding, an ultrasonic vibration tool directly contacts with the plate sheet of the heat exchanger. The laser welding auxiliary process device designed according to the invention can effectively solve the problems of clamping difficulty of plate sheets made from different materials of the heat exchanger and gas protection of a welding connector, meanwhile, an auxiliary action of the ultrasonic vibration can reduce or eliminate a welding residual stress, refine welding seam crystal grains, homogenize a welding seam tissue, and reduce pore and crack defects, thus improving a welding anticorrosion performance and mechanical performances, and prolonging the service life of the plate heat exchanger.