44results about How to "Dense metallographic structure" patented technology

A manufacturing engineering of a large power low speed diesel engine bush belongs to the manufacturing technical field of the large-scale machinery bush. The invention makes the bush manufacturing according to the processing sequence: from the blank manufacturing, blank casting surface deal (blasting process and cleaning), hot dip coating, casting babbit, finish machining to final inspection. The invention has the characteristic of simple manufacture, high product intensity, good quality, high reliability, low cost etc., so the products has even fine texture, high bond strength of the alloy layer, which can satisfy the working request of the large power low speed diesel engine bush. The invention can be widely used in the large-scale heavy duty machinery, specially for the boat large power low speed diesel engine.

The invention relates to a preparation method of a magnesium-aluminum layered composite plate, aiming at solving the problems that the magnesium-aluminum alloy plate is light in weight, low in strength and poor in corrosion resistance. The method comprises the steps of: pressing and labeling a layer of aluminum plate on the magnesium-aluminum alloy plate; taking magnesium-aluminum eutectic alloy powder as a pressing and labeling material; pressing and labeling the magnesium-aluminum alloy plate+the magnesium-aluminum eutectic alloy powder+the aluminum plate into a magnesium-aluminum layered composite plate in an open-close through groove mould on a press machine under the temperature of 480 DEG C and the pressure of 30M Pa for 60s; and performing the low-temperature thermal treatment, so that an internal metallographic phase tissue of the magnesium-aluminum layered composite plate is more compact and stable. The method is advanced and reasonable, small in use equipment, short in technological process, and fast in speed. The mechanical property tensile strength of the magnesium-aluminum layered composite plate can reach 24MPa. Compared with the prior art, the mechanical property tensile strength can be improved by 95%, and the corrosion resistant performance can be improved by 94%, therefore, the preparation method of the magnesium-aluminum layered composite plate is very ideal.

The invention discloses a processing technology of a robot RV speed reducer needle gear shell, and belongs to the technical field of robot RV speed reducer processing. The processing technology includes the steps that precise casting or forging is carried out on a needle gear shell blank; the needle gear shell blank is clamped after the surface of the needle gear shell blank is machined, and the rotation center of the needle gear shell blank is taken as a positioning reference; the end face of the needle gear shell blank, a bearing position of a roller pin bearing and bearing positions of two main bearings are machined; finish machining is carried out on the inner surface of the roller pin bearing according to the positioning reference; finish machining is carried out on a roller pin groove in line contact with a roller pin of the roller pin bearing according to the positioning reference; inner grooves are simultaneously machined in the bearing positions of the two main bearings in a finish machining mode according to the positioning reference; finish machining is carried out on the outer surface of the needle gear blank. The needle gear shell machined according to the steps improves machining precision and the parallelism degree of the bearing positions of the main bearings, guarantees coaxiality, the position degree and cylindricity of the main bearings after installation, achieves one-time clamping, can meet requirements of multiple process parameters, improves machining precision and installation precision of the needle gear shell, reduces accumulated errors, meets the high-precision requirements, and prolongs service life.

The invention discloses a method for preparing a composite coating of alloy co-infiltration, dacromet and sealing layer, which comprises the following steps: weighing the co-infiltration agent raw materials, mixing them uniformly to prepare the co-infiltration agent; treating the clean plate metal The pieces are stacked into stacks with similar height and width, and a layer of co-infiltration agent is laid between adjacent plate-shaped metal parts, and then packed into bundles and put into the co-infiltration furnace; Dacromet anti-corrosion raw materials are weighed, mixed and After stirring evenly, adjust the pH; place the plate-shaped metal parts in the coating liquid dipping cage, then impregnate the Dacromet anti-corrosion coating liquid, rotate and drain, send it to the online drying equipment for baking, and cool to room temperature; Cardanol glycidyl ether is used to prepare a curing agent at room temperature; the pre-preparation component and the curing reaction component are prepared, and the pre-preparation component and the curing reaction component are mixed uniformly to obtain a sealing liquid, and the rotating plate metal parts are subjected to Spraying; drying in a tunnel oven and then placed at room temperature for 24 hours.

The invention relates to a preparation method of an enhanced magnesium alloy-based neutron absorption plate. The method comprises the following steps: aiming at the actual condition of nuclear radiation protection, with boron carbide powder, boron powder, magnesium powder and aluminum alloy powder as raw materials, adopting a vacuum hot-pressing technique under the assisted action of an electric field, and preparing a magnesium alloy-based neutron absorption plate blank under electric field heating, resistance heating, pressurizing and vacuum conditions, so that B4C particles and B particles are evenly distributed in a matrix; oxidation of the material is effectively prevented by the vacuum environment; the interface bonding intensity is improved by the electric field action; the blank is molded in a hot extrusion manner; the particle distribution uniformity is improved; the plastic deformation property of the material is improved; the extruded blank is subjected to hot rolling to obtain the plate; the internal metallographic structure of the material is relatively dense; the preparation method is advanced in process, and accurate, detailed and accurate in data; the neutron absorption property of the magnesium alloy-based neutron absorption plate reaches 98%; the material density reaches 99%; the material hardness reaches HV0.1=186.7; the particle distribution is uniform; and the enhanced magnesium alloy-based neutron absorption plate is a lightweight and high-strength composite plate with good neutron absorption property.

The invention relates to a preparation method of a fine-grained magnesium alloy plate. Aiming at the low strength and plasticity of the magnesium alloy plate, the magnesium alloy plate is rolled and deformed, and the static recrystallization of the deformed structure induced by an electric pulse current is adopted. The plate is processed to make the metallographic structure of the magnesium alloy plate dense and the grains refined, which greatly improves the strength and plasticity of the magnesium alloy plate. This preparation method has advanced technology, accurate and detailed data, and the grain size of the metallographic structure is ≤5μm. The uniformity is good, the tensile strength reaches 295MPa, and the elongation reaches 22%, which is a very ideal method for preparing fine-grained magnesium alloy plates.

Provided is a method for manufacturing a starting ratchet wheel of a motorcycle. Metal powder serves as a raw material and is sintered after compression forming in a mould. The method is characterized in that pressure for compression is 80-115 tons, and dwell pressure for demoulding is 9-15 tons. The metal powder serves as the raw material, is alloyed into alloy steel by compressing and sintering, and is completely free of mechanical cutting, and accordingly waste of steel materials is avoided, steel resource is greatly saved, and the produced starting ratchet wheel of the motorcycle has mechanical performance of the alloy steel, the mechanical performance and overall quality of the starting ratchet wheel are further improved, and production efficiency is also greatly increased. The method is simple in production process, the starting ratchet wheel is high in precision and fine in consistency, and stability of quality of products in mass production is guaranteed.

The invention discloses a method for smelting ultra-low carbon stainless steel through an intermediate frequency furnace. The method comprises the specific steps of firstly, molten iron pretreatment; secondly, intermediate frequency smelting; thirdly, oxygen blowing and carbon reducing; fourthly, microelement adding; fifthly, deoxidation treatment; sixthly, casting shaping; and seventhly, electroslag remelting. An intermediate frequency furnace smelting manner and an electroslag remelting refining manner are adopted to produce the ultra-low carbon stainless steel, the production manner is flexible, and the material supply manner of small batches, multiple specifications and urgent demands of a customer can be met; the intermediate frequency furnace is high in smelting speed, good in power-saving effect, few in burning loss and low in energy consumption; the smelting efficiency is improved; and electroslag remelting refining is adopted to enable the inner structure of a steel ingot to be more compact, and the ultra-low carbon stainless steel is high in purity, low in sulfur containing, less in nonmetallic inclusion, smooth in surface, clean, even and compact and even in gold phase structure and chemical component.

The invention relates to a manufacturing process of a bearing bush of a high-power low-speed diesel engine, which belongs to the technical field of manufacturing bearing bushes of large mechanical equipment. In the invention, the bearing bush is manufactured according to the technological sequence of: rough blank manufacturing → blank pouring surface treatment (shot blasting treatment and cleaning) → tin enamel → casting babbitt alloy → finishing machining and final inspection. Because the method of the present invention has the characteristics of simple manufacture, high product strength, good quality, high reliability, and low production cost, the product manufactured by the process of the present invention has a uniform metallographic structure, high bonding strength of the alloy layer, and can meet large Therefore, the bearing bush manufactured by the present invention can be widely used in large-scale heavy-duty mechanical equipment, and is especially suitable for marine high-power low-speed diesel engines.

The invention relates to a coating hot-pressing reinforcement method of a magnesium-aluminum alloy plate. According to the coating hot-pressing reinforcement method, aiming at the situations of soft texture, low hardness and strength and poor corrosion resistance of the magnesium-aluminum alloy plate, a layer of magnesium-aluminum-erbium alloy coating is formed on the magnesium-aluminum alloy plate through hot-pressing sintering by taking rare earth erbium as a reinforcing agent and using the steps of casting of magnesium-aluminum-erbium alloy, powder forming through ball milling, hot-pressing sintering and low-temperature tempering, wherein firm bonding between the coating and the alloy plate is achieved, therefore strength, hardness and corrosion resistance of the magnesium-aluminum alloy plate are greatly increased, coating hardness reaches 270HV which is increased by 3.55 times, and corrosion resistance of the magnesium-aluminum alloy plate with the magnesium-aluminum-erbium alloy coating is increased by 519 percent compared with that of the magnesium-aluminum alloy plate without the magnesium-aluminum-erbium alloy coating. The preparation method disclosed by the invention has the advantages of advanced process, detailed and accurate magnitude, good coating bonding force, compact metallographical tissues and capability of being applied in multiple industrial fields and is the very ideal coating hot-pressing sintering reinforcement of the magnesium-aluminum alloy plate.