32results about How to "Solve the problem of thermal cracking" patented technology

The invention discloses a method for connecting 2XXX and 7XXX heterogeneous aluminum alloy by the laser filler wire, which is suitable for the connection field of 2XXX and 7XXX-series of heterogeneous aluminum alloy. The method comprises the following steps of: firstly, assembling two aluminum alloy plates to be welded into a butt joint mode; regulating position relationship among a laser focal point, the wire falling point of an aluminum alloy welding wire and a butt joint gap between two aluminum alloy plates to ensure that the laser beam, the welding wire and the welded aluminum alloy plates are positioned on the reasonable opposite positions; and adopting reasonable welding parameters, laser power, welding speed, wire conveying speed and the like, utilizing AlCu or Alsi welding wires as filler material in the welding process to regulate the ingredient of the welding line and improve the performance of the joint. According to the method, the problems that the 2XXX and 7XXX heterogeneous aluminum alloy is difficult to connect, the welding line is softened during melting, and heat checking tendency exists can be solved.

The invention relates to a low heat track sensitive high-toughness casting aluminium copper alloy which is characterized in that: on the basis of the body material, 0.001-1 percent of M is added by mass percent, and M is one of Ce, La and Y or arbitrary combination thereof; aiming at heat cracks of the aluminium copper alloy, the heat cracking inclination of the high-toughness aluminium copper alloy can be effectively reduced by microalloying and adding trace rare-earth elements, so as to develop the high-toughness casting aluminium copper alloy with low heat-cracking inclination successfully; under the same intensity, the defect of heat crack generation can be effectively reduced.

The invention discloses a gasoline engine turbocharger, which comprises a worm wheel casing, a middle body and a compressor casing, wherein the worm wheel casing, the middle body and the compressor casing are connected together. A worm in the turbocharger is provided with a hollow portion, a worm wheel and the worm are fixedly installed together by adopting an electron beam welding process, a heat shield is arranged between the middle body and the worm wheel casing, and a lubricating oil cavity and a cooling water cavity are arranged in the middle body. The worm wheel casing is formed by casting nodular cast iron, an inner thrust bearing is arranged between the middle body and a worm wheel shaft, an outer thrust bearing is arranged between the compressor casing and the worm wheel shaft, and a thrust piece is arranged between the inner thrust bearing and the outer thrust bearing. A sealing sleeve is sleeved on the worm wheel shaft, the outer thrust bearing is installed on the sealing sleeve, and an actuator comprises an air-release valve and an air valve connecting rod. The gasoline engine turbocharger effectively block heat transfer from the worm wheel end to the middle body, ensures lubrication quality of lubricating oil at the worm wheel end, solves the problems including worm wheel shaft getting-stuck, shaft grinding and the like caused by lubrication failure of a floating bearing, and solves the problem that the side of an air compressor of the gasoline engine turbocharger leaks oil.

Aluminum-zinc-magnesium-zirconium base alloys and aluminum-zinc-magnesium-copper-zirconium base alloys that exhibit ultra-high strength and superior weldability, and methods of fabricating them.

The invention discloses a Cu-Zr-Ag alloy crystallizer copper plate, containing metal Zr of 0.05 to 0.25wt%, deoxidizing agent metal Mg of 0.05wt%, metal Ag of 0.06 to 0.15wt% and metal Cu of 99.65 to 99.77wt%. The invention also discloses a preparation process of the Cu-Zr-Ag alloy crystallizer copper plate, which has better heat conductivity and high pulling resistance and higher softening temperature, the service life of the crystallizer copper plate is prolonged, pull speed of a slab casting machine is improved, production efficiency of slabs is greatly improved, and the copper plate is a novel long-service life crystallizer copper plate suitable for high-pull speed, high-efficiency, high-pace and high-yield continuous casting operation.

The invention belongs to the field of electrostatic-type exhaust treatment systems and discloses a composite automobile exhaust particle filtering device. The device is characterized in that an electric charging device is disposed in an exhaust pipeline; the electric charging device is connected to a high-voltage positive electrode; the outer wall of the exhaust pipeline is connected to a grounding electrode; an electrostatic field is formed in the exhaust pipeline to conduct pre-charging of exhaust particles; a metal filtering screen is disposed at a discharge hole of the exhaust pipeline to collect the exhaust particles; the electric charging device is a center pillar, multiple parallel electrode pillars or an electrode board; and devices such as an electric field stabilization device, a compressed air control pipeline, a gas state detection sensor and a pressure sensor are also disposed on the exhaust pipeline to promote electric field stabilization and collect the exhaust particles. The filtering device disclosed by the invention has the advantages that a demand for exhaust filtering under different loads, especially heavy loads, can be satisfied; the electric charging capability of a filtering system can be enhanced effectively, and particle collection can be perfected; filtering performance can be improved; the efficiency is high; and the filtering performance is stable.

The invention provides a metal-ceramic composite coating layer for a steel piston. A mature arc spraying technology is introduced; a layer of such compact materials easy to perform electrochemical oxidation as aluminum, magnesium and titanium is firstly prepared on the top surface of the steel piston; and then, on this basis, such electrochemical methods as hard anodic oxidation and microarc oxidation are used for preparing a thermal insulation layer. An area to be treated of the steel piston is machined; the arc spraying is adopted to form a metal transition layer on the surface of the machined steel piston; the steel piston covered with the metal transition layer is secondarily machined; and a ceramic thermal insulation layer is prepared on the surface of the secondarily machined steel piston by adopting the electrochemical method. As the metal spraying difficulty is far lower than the spraying of such ceramic materials as zirconium oxide and aluminum oxide, the arc spraying is particularly adopted, and the manufacturing cost is greatly reduced.

The invention discloses a method for avoiding a hot crack on the outer layer of a high speed steel roll for rods and wires. The method includes the following steps: a centrifugal pattern is adopted to forge the outer layer of the high speed steel roll; during centrifugal casting of the outer layer, the rotating speed of a centrifuge is changed by phase, and the molten steel casting speed and the rotating speed of the centrifuge are changed accordingly; at the starting phase of the centrifugal casting, a high rotating speed and high-speed casting are adopted; at the medium phase of the centrifugal casting, a medium rotating speed and low-speed casting are adopted; after casting is finished, a low rotating speed is adopted. Through the variable-speed centrifugal casting of molten steel for the outer layer of the high speed steel roll, the molten steel mold filling is facilitated at the starting phase of casting; molten steel is guaranteed to quickly and evenly cover the entire inner chamber of a casting mold; cold-lap, cold shut and other defects are avoided; the stress on the centrifugal outer layer is also improved; element segregation on the outer layer is reduced; stress cracking tendency is reduced; finally, the purpose of preventing the outer layer from the hot crack is achieved.

The invention provides a precipitation strengthening nickel-based high-temperature alloy laser powder bed melting forming method capable of reducing hot cracks. According to the method, rare earth element oxide particles and precipitation strengthening nickel-based high-temperature alloy powder are mixed and then subjected to laser powder bed melting forming, the rare earth element oxide particles and the precipitation strengthening nickel-based high-temperature alloy powder interact under the action of continuous laser, and therefore harmful elements in the original precipitation strengthening nickel-based high-temperature alloy powder can be enriched, segregation of the harmful elements along the crystal boundary is reduced, forming of a liquid film of melt at the final stage of solidification is correspondingly hindered, and the hot cracks are greatly reduced.

The invention discloses a high-temperature wear-resistant self-lubricating side guide plate lining plate and a machining method thereof. The side guide plate lining plate is of a sandwich structure, a middle base plate is made of 45 steel, high-temperature wear-resistant self-lubricating layers obtained through laser cladding are arranged on the two sides of the middle base plate, each high-temperature wear-resistant self-lubricating layer is composed of 85-97 wt% of high-entropy alloy, 1-5 wt% of hexagonal boron nitride and 2-10 wt% of eutectic BaF2/CaF2, the high-entropy alloy is NiFeAlCoCrB<x> and is composed of Ni, Fe, Al, Co and Cr which are equal in mole and B with the mole content of x, x ranges from 0.02 to 0.1, and the high-temperature wear-resistant self-lubricating layers are formed on the surface of the middle base plate through two paths of laser cladding. The hardness of the lining plate is improved by adopting the high-entropy alloy, the high-temperature lubricity of the lining plate is improved by adopting boron nitride and eutectic BaF2/CaF2 together, and the problems that a side guide plate lining plate is fast in abrasion and short in service life and the end face of strip steel is strained during hot rolling of the strip steel are effectively solved.

The invention relates to a single arm structure for a thermoelectric semiconductor temperature sensing sheet and a preparation process, and aims to solve the technical problem of thermal cracks caused by large thermal stress in a like product. The single arm structure for the thermoelectric semiconductor temperature sensing sheet comprises a thermoelectric semiconductor and Cu guide vanes positioned at the two ends of the thermoelectric semiconductor, wherein three transition layers, i.e. an Ni-coated layer, an Ni-plated layer and an Sn95Ag5-plated layer, are arranged between each of the two ends of the thermoelectric semiconductor and the corresponding Cu guide vane; the Ni-coated layers, the Ni-plated layers and the Sn95Ag5-plated layers are sequentially arranged from the end parts of the thermoelectric semiconductor to the surfaces of the Cu guide vanes. According to the single arm structure and the preparation process, the transition layers are arranged, so that a buffering function is realized, and the thermal stress which is generated between the thermoelectric conductor and the Cu guide vanes caused by the great thermal expansion coefficient difference is reduced; the single arm structure is high in thermal stability and suitable for various thermoelectric semiconductor temperature sensing sheets, the problem of thermal cracks in a thermoelectric semiconductor temperature sensor is solved, and the service life of the temperature sensor is prolonged.

The invention discloses a method for controlling precipitation of a delta phase in a Nb-containing nickel-based superalloy, and belongs to the technical field of superalloy materials. The method comprises the steps of burdening, casting and heat treatment, Al, Ti and microelements B and Hf are added on the basis of original material chemical components, and according to experimental verification, when the addition amount of Al is 0.5-1.5 wt%, the addition amount of Ti is 0.2-1.0 wt%, the addition amount of B is 0.0010-0.0075 wt% and the addition amount of Hf is 0.1-1.00 wt%, the effects of controlling precipitation of the delta phase in a grain boundary area, reducing a gamma" metastable phase, inhibiting conversion from gamma" to the delta phase, and promoting the precipitation of a stable precipitation strengthening phase are achieved. Therefore, the endurance life, the strength and the structure stability of the materials are remarkably improved.