Deep good article sharing, on a variety of metal forming process
Release time:2021-12-08Click:990
01 casting liquid metal is poured into the mold cavity which is suitable for the shape and size of the part, and then it is cooled and solidified to obtain the production method of the blank or part, which is usually called liquid metal forming or casting. Process flow: Liquid Metal → filling → solidification shrinkage → casting
Process Features: Can Produce arbitrarily complex shape parts, especially the parts with complex inner cavity shape, strong adaptability, alloy type is not limited, casting size is almost unlimited, material source is wide, scrap can be remelted, low Equipment Investment, high reject rate, low surface quality, poor working conditions
Sand casting: casting method of producing castings in a sand mold. Steel, iron, and most non-ferrous alloy castings can be obtained by sand casting.
Advantages: high dimensional and geometric precision, high Surface roughness, able to cast castings with complex shapes, and cast alloys without restrictions. DISADVANTAGES: Complex Processes, hIGH-COST APPLICATIONS: FOR THE PRODUCTION OF COMPLEX SHAPE, high precision requirements, or difficult to process other small parts, such as turbine engine blades. Die Casting
Die Casting: The use of high-pressure metal liquid high-speed pressure into a precision metal mold cavity, the metal liquid under pressure cooling solidification and forming castings.
Advantages: die-casting liquid metal under high pressure, fast flow product quality, size stability, good interchangeability high production efficiency, die-casting die number of use more suitable for mass production, advantages and disadvantages of good economic benefits: The castings are easy to produce small air holes and loose die castings with low plasticity, and it is not suitable to work under impact load and vibration, when the die casting mould life of high melting point alloy is low, iNFLUENCE THE EXPANDED APPLICATION OF DIE CASTING PRODUCTION: Die Casting was first applied in automobile industry and instrument industry, and then gradually expanded to various industries, such as agricultural machinery, machine tool industry, electronics industry, national defense industry, computer, medical equipment, watches, cameras and daily hardware and other industries. (4) low pressure casting
LOW PRESSURE CASTING: the process of filling a mold with liquid metal at low pressure (0.02 ~ 0.06 MPA) and crystallizing under pressure to form a casting. Process flow:
Technical features: the pressure and speed can be adjusted during pouring, so it is suitable for various casting molds (such as metal mold, sand mold, etc.) , casting all kinds of alloys and castings of various sizes using bottom pouring mold, metal liquid mold filling is stable, no splash phenomenon, it can avoid the entrainment of gas and the erosion of the mold wall and the mold core, improve the qualified rate of the casting, the casting crystallizes under the pressure, the casting structure is compact, the outline is clear, the surface is smooth, the mechanical property is higher, for the casting of large thin-walled parts, it is especially advantageous to eliminate feeding risers, to increase the metal utilization rate to 90 ~ 98% , labor intensity is low, working conditions are good, and equipment is simple, eASY TO REALIZE MECHANIZATION AND AUTOMATION APPLICATION: the traditional products mainly (cylinder head, wheel hub, cylinder frame, etc.) . (5) Centrifugal Casting
Centrifugal casting: It is a kind of casting method in which liquid metal is poured into the rotating mould and the mould is filled under the action of Centrifugal Force. Process flow:
Advantages: almost no metal consumption of gating system and riser system, high process yield, no core can be used in hollow castings, so the metal filling capacity can be greatly improved in long tubular castings with high density, there are few defects such as gas hole and slag inclusion, and the mechanical property is high, which is convenient to make the composite metal castings of cylinder and sleeve, centrifugal casting was first used in the production of cast pipes. Centrifugal casting was used in metallurgy, mining, transportation, drainage and Irrigation Machinery, aviation, national defense, automobile and other industries at home and abroad, for the production of steel, iron and non-iron carbon alloy castings. In particular, Centrifugal cast iron pipe, internal combustion engine cylinder sleeve and the most common casting. (6) gravity die casting
PERMANENT MOLD CASTING: A molding process in which liquid metal is filled with a permanent mold by gravity and then cooled and solidified in the mold to obtain a casting. Process flow:
Advantages: high thermal conductivity and heat capacity, fast cooling rate, compact casting structure, mechanical properties 15% higher than sand casting can achieve higher dimensional accuracy and lower Surface roughness, and good quality and stability because do not use and very little sand core, improve the environment, reduce dust and harmful gases, reduce Labor intensity shortcomings: the metal type itself has no permeability, it is necessary to take some measures to deduce the non-yielding of gas metal mold produced by air and sand core in the mold cavity. Therefore, it is only when mass production is carried out that good economic results can be achieved: the permanent mold casting is suitable for both aluminum alloy and magnesium alloy castings with complex mass production shapes, also suitable for the production of iron and steel metal castings, ingots and so on. (7) Vacuum Die Casting: The elimination or significant reduction of air holes and dissolved gases in die castings by the removal of gases from the die cavity during die casting, advanced Die Casting Technology for improving mechanical properties and surface quality of die castings. Process flow:
Advantages: elimination or reduction of air holes in Die Castings, improvement of mechanical properties and surface quality of die castings, improvement of plating properties and reduction of back pressure in die cavities, use of alloys with low specific pressure and poor casting properties, it is possible to use small machines to die-cast large castings to improve the filling conditions, but die-cast thin castings disadvantages: Die Seal structure is complex, manufacture and installation is more difficult, so the cost of vacuum die-casting method such as improper control, it’s not very effective. (8) squeezing die casting
Squeeze Casting: Liquid or semi-solid metal solidification under high pressure, flow forming, direct access to parts or blank method. It has the advantages of high utilization rate of liquid metal, simple process and stable quality. It is an energy-saving metal forming technology with potential application prospect. Process flow:
DIRECT SQUEEZE CASTING: Spray coating, casting alloy, mold closing, pressurization, pressure keeping, pressure releasing, mold parting, blank demoulding, resetting; indirect Squeeze Casting: Spray coating, mold closing, feeding, mold filling, pressurization, pressure keeping, pressure releasing, parting, stripping, resetting. Technical Features: it can eliminate internal defects such as porosity, shrinkage cavity and porosity, low Surface roughness, high dimensional accuracy can prevent casting crack, easy to realize mechanical and automatic application, can be used to produce various types of alloy, such as aluminum alloy, zinc alloy, copper alloy, Ductile Iron and so on (9) Lost-foam casting (Lost foam casting) direct squeeze casting: Spray coating, casting alloy, mold, pressurization, pressure protection, pressure relief, mold, blank demoulding, reset; Indirect Squeeze Casting: Spray coating, mould closing, feeding, filling, pressurizing, pressure keeping, pressure releasing, parting, blank demoulding, resetting. Technical Features: it can eliminate internal defects such as porosity, shrinkage cavity and porosity, low Surface roughness, high dimensional accuracy can prevent casting crack, easy to realize mechanical and automatic application, can be used to produce various types of alloy, examples include aluminum, zinc, copper, and ductile iron Lost-foam casting (Lost foam casting)
Technical features: High precision casting, no sand core, reduced processing time no parting surface, flexible design, high degree of freedom clean production, no pollution to reduce investment and production costs application: suitable for the production of various sizes of complex precision casting, there is no limit to the variety of alloy and to the quantity of production. Such as gray iron engine case, high manganese steel elbow and so on. Continuous casting continuous casting continuous casting continuous casting continuous casting continuous casting continuous casting continuous casting continuous casting continuous casting continuous casting continuous casting continuous casting continuous casting continuous casting continuous casting, continuously pulled from the other end of the mold, it can obtain any length or a specific length of casting. Process flow:
Technical features: Because the metal is cooled rapidly, crystallized and compact, the structure is uniform, the mechanical property is better, the metal is saved, the production rate is increased, the working procedure is simplified, the molding and other working procedures are avoided, thus the Labor intensity is reduced; The required production area is also greatly reduced and continuous casting production is easy to realize mechanization and automation, application: continuous casting method can be used to cast steel, iron, copper alloy, aluminum alloy, magnesium alloy and other cross-section shape of the same long castings, such as Ingot, slab, bar, pipe, etc. . 02 plastic forming plastic forming: is the use of plastic materials, tools and molds in the role of the external force to process parts of the less-cutting or non-cutting process. It has many kinds, including forging, rolling, extrusion, drawing, stamping and so on. (1) forging: Forging is a method of using forging machinery to apply pressure on a metal blank to produce plastic deformation in order to obtain a piece with certain mechanical properties, shape and size. According to forming mechanism, forging can be divided into free forging, die forging, rolling ring and special forging. Free forging: A process in which metal ingots or blocks are hammered into desired shapes and sizes using simple tools, usually on a hammer or hydraulic press. Die Forging: Forming by means of a die on a die forging hammer or hot die forging press. Grinding ring: refers to the production of different diameter ring parts through special equipment grinding ring machine, but also used to produce car wheels, train wheels and other wheel-shaped parts. Special forging: including roll forging, Cross Wedge Rolling, radial forging, liquid die forging and other forging methods, these methods are more suitable for the production of some special shape parts.
Process flow: heating of forging blank, roll forging, die forging, trimming, piercing, rectification, intermediate inspection, heat treatment of forging, cleaning, rectification, inspection, plasticity, toughness and other mechanical properties are also higher than casting or even higher than rolling parts to save raw materials, but also can shorten processing time production efficiency high free forging suitable for single piece small batch production, flexible applications: Large Rolling Mill Rolls, herringbone gears, electric generator rotors, impellers, retaining rings, huge hydraulic cylinders and columns, locomotive axles, automotive and tractor crankshaft, connecting rods, etc. . (2) rolling
Rolling: The process of rolling metal through the gap of a pair of rotating rollers (various shapes) to reduce the cross section and increase the length of the material. Rolling Classification: According to the Movement of rolling pieces are divided into: Vertical Rolling, Cross Rolling, cross rolling. Longitudinal Rolling: The process by which metal passes between two rollers that rotate in opposite directions, causing plastic deformation. Cross Rolling: the Movement Direction of the workpiece after deformation is consistent with the direction of the roll axis. Skew Rolling: Rolling piece for spiral movement, piece and Roll Axis non-special angle.
Applications: mainly used in metal profiles, plates, tubes, and other non-metallic materials such as plastic and glass products. (3) extrusion: under the action of three-dimensional non-uniform compressive stress, the billet is extruded from the hole or gap of the die to reduce the cross-sectional area and increase its length. Process flow: preparation before extrusion → heating of cast bar → extrusion → stretching twisting straightening → sawing (fixed length)→ sampling inspection → artificial aging → packing and storage
Advantages: A wide range of production, product specifications, variety of production flexibility, suitable for small batch production of products with high dimensional accuracy, surface quality, equipment investment, small plant area, easy to realize automatic production defects: Big Loss of geometric waste metal flow low uneven extrusion speed, long auxiliary time tool loss, high cost production scope: mainly used for Manufacturing Long Rod, Deep Hole, thin wall, special section parts. (4) drawing: A plastic process in which an external force is applied to the front end of the metal being drawn to pull the blank out of a die hole smaller than the blank section in order to obtain a product of the appropriate shape and size.
Advantages: precision in size, long products with small cross-section can be produced continuously with simple and clean tools and equipment. The limited length between pass deformation and two-step annealing limits the production scope: drawing is the main processing method for metal pipes, bars, profiles and wires. (5) stamping advantages: precision in size, long products with small cross-section can be produced continuously with simple and clean tools and equipment. The limited length between pass deformation and two-step annealing limits the production scope: drawing is the main processing method for metal pipes, bars, profiles and wires. (5) stamping
Technical Features: Light Weight and high rigidity can be obtained. Good producibility, suitable for mass production, low cost and uniform quality products. High Material Utilization Rate, good shearing and recyclability, there are 60 ~ 70% of sheet metal, most of which are pressed into finished products. Automobile Body, Chassis, fuel tank, radiator plate, boiler drum, container shell, motor, electrical appliances, such as iron core silicon steel sheet are stamping processing. Instruments, household appliances, bicycles, office machinery, household utensils and other products, there are a large number of stamping parts. 03 machining
MACHINING: In the production process of parts, the cutter is directly used to cut off the excess metal layer thickness on the blank, making it or drawing required by the size precision, shape and location of mutual precision, surface quality and other technical requirements of the processing process.
04 Welding: also known as fusion welding, fusion welding is a manufacturing process and technique for joining metals or other thermoplastic materials such as plastics by means of heating, high temperature or high pressure.
05 POWDER METALLURGY POWDER METALLURGY: formed and sintered from metal or metal powders (or a mixture of metal and non-metal powders) , the manufacture of metal materials, composites and various types of products of the process technology. Basic process flow:
Advantages: The vast majority of refractory metals and their compounds, pseudo alloys, and porous materials can only be made by the Powder metallurgy method to save metal, reduce product costs without any pollution to the materials, it is possible to make high purity materials by the Powder metallurgy method, which guarantees the correctness and uniformity of the composition of the materials, Powder metallurgy being suitable for the production of a large number of products of the same shape, can greatly reduce production costs disadvantages: In the absence of a lot to consider the size of parts mold cost is relatively higher than casting mold production scope: Powder metallurgy can be made directly into porous, semi dense or fully dense materials and products, such as oil bearing, gear, Cam, guide Rod, cutter and so on. 06 Metal injection Molding (Mim) : Short for Metal Injection Molding. Is a molding method in which a plasticized mixture of metal powder and its binder is injected into a mold. It is first selected powder and binder for mixing, and then the mixture for granulating and then injection molding required shape. Mim Process Flow: divided into four unique processing steps (mixing, molding, degreasing and sintering) to achieve the production of parts, based on product characteristics to determine whether the need for surface treatment.
Technical Features: one-step molding responsible for parts surface quality, low reject rate, high production efficiency, easy to achieve automation for MOLD MATERIALS LOW-TECH CORE: the core of the MIM technology is the adhesive, only a certain amount of adhesive is added, the powder has enhanced fluidity to be suitable for injection molding and to maintain the basic shape of the billet. 07 METAL SEMI-SOLID FORMING SEMI-SOLID FORMING: The use of non-dendritic semi-solid metal (SSM) unique rheology and melt to control the quality of the casting. Semi-solid forming can be divided into rheological forming and thixoforming. (1) Rheoforming
Technical Features: reduce liquid molding defects, significantly improve quality and reliability molding temperature is lower than all liquid molding temperature, at present, it has been successfully used in the manufacture of main cylinder, steering system parts, rocker arm, engine piston, wheel hub, transmission system parts, fuel system parts and air conditioning parts, etc. . 083D Printing 3D PRINTING: A type of Rapid prototyping, it is a technique for building objects layer by layer, based on digital model files, using adhesive materials such as powdered metal or plastic.
Source: metalworking
Disclaimer: Some pictures and texts on this site are collected from the Internet and are only for learning and communication. The copyright belongs to the original author and does not represent the views of our site. This site will not bear any legal responsibility. If your rights are violated, please contact us to delete it in time.