As an engineer, you must have been exposed to the processing technology of various materials. Today, I will mainly introduce metal forming and plastic forming, and summarize the animations of forming, surface processing, linking and cutting for you. I hope it can be helpful to you.
metal forming
Die casting (note that die casting is not an abbreviation for pressure casting) is a metal casting process characterized by applying high pressure to molten metal using a mold cavity. Molds are usually machined from stronger alloys, a process somewhat similar to injection molding.
Sand casting is the use of sand to make molds. Sand mold casting needs to put the finished part model or wooden model (pattern) in the sand, then fill the sand around the pattern, and take out the pattern after opening the box to form the mold.
In order to take out the model before casting the metal, the mold should be made into two or more parts; during the mold making process, holes and vent holes for pouring metal into the mold must be left to form a pouring system. After pouring the liquid metal into the mold, keep it for an appropriate time until the metal solidifies. After the parts were removed, the molds were destroyed, so new molds had to be made for each casting.
Investment casting, also known as lost wax casting, includes processes such as wax pressing, wax repairing, tree formation, dipping, melting wax, casting molten metal and post-processing. Lost wax casting is to use wax to make a wax mold of the part to be cast, and then coat the wax mold with mud, which is the mud mold. After the clay mold is dried, it is fired into a pottery mold. Once fired, all the wax molds are melted and lost, leaving only the pottery molds. Generally, when the mud mold is made, the sprue is left, and then the molten metal is poured into the sprue, and after cooling, the required parts are made.
Die forging is a forging method that uses a die to form a blank to obtain a forging on a special die forging equipment. According to different equipment, die forging is divided into hammer die forging, crank press die forging, flat forging machine die forging, friction press die forging, etc. Roll forging is a plastic forming process in which the material is plastically deformed under the action of a pair of counter-rotating dies to obtain the desired forging or forging billet. It is a special form of form rolling (longitudinal rolling).
Forging is a processing method that uses forging machinery to apply pressure to metal blanks to cause plastic deformation to obtain forgings with certain mechanical properties, certain shapes and sizes. It is one of the two major components of forging (forging and stamping). Forging can eliminate defects such as as-cast porosity produced in the metal smelting process and optimize the microstructure. At the same time, due to the preservation of complete metal flow lines, the mechanical properties of forgings are generally better than castings of the same material. For important parts with high loads and severe working conditions in related machinery, forgings are mostly used, except for plates, profiles or weldments that can be rolled with simpler shapes.
Rolling Also known as calendering, refers to the process of giving a metal ingot its shape by passing it through a pair of rollers. If the temperature of the metal exceeds its recrystallization temperature during rolling, the process is called "hot rolling", otherwise it is called "cold rolling". Calendering is the most commonly used means in metalworking.
Die casting is essentially a method of filling the cavity of a die-casting mold (die-casting mold) with liquid or semi-liquid metal at a high speed under high pressure, and forming and solidifying under pressure to obtain a casting.
Low-pressure casting is a casting method in which liquid metal is filled into a mold and solidified into a casting under the action of low-pressure gas. Low-pressure casting was initially mainly used for the production of aluminum alloy castings, and later expanded its use to produce copper castings, iron castings and steel castings with high melting points.
Centrifugal casting is a technology and method of injecting liquid metal into a high-speed rotating mold so that the molten metal fills the mold and forms a casting under the action of centrifugal force. The casting mold used in centrifugal casting can be non-metallic mold (such as sand mold, shell mold or investment shell mold), metal mold or coated with paint layer or resin sand layer in the metal mold according to the shape, size and production batch of the casting. cast.
Lost foam casting is to bond and combine paraffin or foam models similar in size and shape to castings to form model clusters. After brushing refractory paint and drying, they are buried in dry quartz sand for vibration modeling, and poured under negative pressure to vaporize the model. , a new casting method in which liquid metal occupies the position of the model, solidifies and cools to form a casting. Lost Foam Casting is a new technology with nearly no margin and precise molding. This process does not require mold taking, no parting surface, and no sand core. Dimensional errors caused by combination.
Squeeze casting, also known as liquid die forging, is to inject molten metal or semi-solid alloy directly into the open mold, and then close the mold to generate filling flow to reach the outer shape of the workpiece, and then apply high pressure to make the solidified The metal (shell) produces plastic deformation, the unsolidified metal is subjected to isostatic pressure, and high-pressure solidification occurs at the same time, and finally the method of obtaining the workpiece or blank, the above is direct extrusion casting; there is also indirect extrusion casting that refers to melting metal or semi The solid alloy is injected into a closed mold cavity through a punch, and high pressure is applied to make it crystallize and solidify under pressure, and finally obtain a workpiece or blank.
Continuous casting is a casting method in which liquid metal is continuously poured into one end of a through mold and the molding material is continuously pulled out from the other end.
Drawing is a plastic processing method that uses external force to act on the front end of the drawn metal to pull the metal blank out of a die hole smaller than the section of the blank to obtain a product of corresponding shape and size. Since drawing is mostly carried out in a cold state, it is also called cold drawing or cold drawing.
Stamping is a forming processing method that applies external force to plates, strips, pipes and profiles by presses and molds to cause plastic deformation or separation to obtain workpieces (stamping parts) of required shape and size.
Metal Injection Molding (Metal Injection Molding, referred to as MIM) is a new type of powder metallurgy near-net forming technology derived from the plastic injection molding industry. As we all know, plastic injection molding technology produces products of various complex shapes at a low price, but plastic The strength of the product is not high. In order to improve its performance, metal or ceramic powder can be added to the plastic to obtain a product with higher strength and good wear resistance. In recent years, this idea has evolved to maximize the solids content and completely remove the binder and densify the shaped body during subsequent sintering. This new powder metallurgy forming method is called metal injection molding.
Turning refers to lathe processing is a part of mechanical processing. Lathe processing mainly uses turning tools to turn rotating workpieces. Lathes are mainly used to process shafts, disks, sleeves and other workpieces with rotating surfaces, and are the most widely used type of machine tool processing in machinery manufacturing and repair factories. Turning is a method of cutting a workpiece on a lathe by using the rotation of the workpiece relative to the tool. The cutting energy for turning operations is primarily provided by the workpiece rather than the tool.
Turning is the most basic and common cutting processing method, which occupies a very important position in production. Turning is suitable for machining rotary surfaces. Most workpieces with rotary surfaces can be processed by turning methods, such as inner and outer cylindrical surfaces, inner and outer conical surfaces, end faces, grooves, threads, and rotary forming surfaces. The tools used are mainly turning tools.
Milling Milling is to fix the blank, and use a high-speed rotating milling cutter to move on the blank to cut out the required shape and features. Traditional milling is mostly used for simple shapes/features such as milling contours and slots. CNC milling machines can process complex shapes and features. The milling and boring machining center can perform three-axis or multi-axis milling and boring processing, which is used to process molds, inspection tools, molds, thin-walled complex surfaces, artificial prostheses and blades, etc. When selecting the content of CNC milling, the advantages and key roles of CNC milling machines should be fully utilized.
Planing processing is a cutting processing method in which a planer is used to perform horizontal relative linear reciprocating motions on a workpiece, and is mainly used for shape processing of parts. The precision of the planing process is IT9~IT7, and the surface roughness Ra is 6.3~1.6μm.
Grinding Grinding refers to the processing method of removing excess material on the workpiece with abrasives and abrasive tools. Grinding is one of the most widely used cutting methods.
Selective laser melting In a tank covered with metal powder, the computer controls a beam of high-power carbon dioxide laser to selectively sweep across the surface of the metal powder. Where the laser light hits, the metal powder on the surface is completely melted and combined, while the place where the laser does not shine remains in a powder state. The whole process needs to be carried out in a sealed cabin filled with inert gas.
Selective laser sintering is the SLS method that uses infrared lasers as energy sources, and most of the modeling materials used are powder materials. During processing, the powder is first preheated to a temperature slightly lower than its melting point, and then the powder is flattened under the action of the scraping roller; the laser beam is selectively sintered according to the information of the layered section under computer control, and one layer is completed. Then proceed to the next layer of sintering, remove the excess powder after all sintering, and then you can get a sintered part. At present, the mature process materials are wax powder and plastic powder, and the process of sintering with metal powder or ceramic powder is still under study.
Metal Deposition Somewhat similar to "creaming" fused deposition, but with a spray of metal powder. While spraying metal powder materials, the nozzle also provides high-power laser and inert gas protection. In this way, it will not be limited by the size of the metal powder box, and can directly manufacture larger volume parts, and is also very suitable for repairing partially damaged precision parts.
Roll Forming The roll forming method uses a series of continuous stands to roll stainless steel into complex shapes. The sequence of rolls is designed such that the roll profile of each stand successively deforms the metal until the desired final shape is obtained. If the shape of the part is complex, up to thirty-six racks can be used, but for simple parts, three or four racks are enough.
Die forging refers to the forging method in which forgings are obtained by forming blanks with dies on special die forging equipment. The forgings produced by this method are precise in size, small in machining allowance, complex in structure and high in productivity.
Die-cutting is the blanking process. The film formed by the previous process is positioned on the male die of the die-cutting die, and the excess material is removed by closing the die, and the 3D shape of the product is retained to match the mold cavity.
Die-cutting process-knife die Cutting die cutting process, positioning the film panel or circuit on the bottom plate, fixing the die cutting machine on the template, and using the force provided by the machine to press down to control the blade to cut the material. The difference between it and the punching die is that the incision is smoother; at the same time, through the adjustment of the cutting pressure and depth, it can punch out indentation, half-cut and other effects. At the same time, the cost of the mold is low, and the operation is more convenient, safe and fast.
plastic molding
Injection molding is a method of producing shapes for industrial products. Products usually use rubber injection molding and plastic injection molding. Injection molding can also be divided into injection molding molding method and die casting method. Injection molding machine (referred to as injection machine or injection molding machine) is the main molding equipment for making thermoplastic or thermosetting materials into various shapes of plastic products using plastic molding molds. Injection molding is achieved through injection molding machines and molds.
Extrusion is a processing method in which the material passes through the action between the extruder barrel and the screw, is heated and plasticized, pushed forward by the screw, and passes through the machine head continuously to make various cross-section products or semi-finished products.
Blow molding, also known as hollow blow molding, is a rapidly developing plastic processing method. The tubular plastic parison obtained by extrusion or injection molding of thermoplastic resin is placed in the split mold while it is hot (or heated to a softened state), and compressed air is injected into the parison immediately after the mold is closed to blow the plastic parison. It swells and clings to the inner wall of the mold, and after cooling and demoulding, various hollow products can be obtained.
Blister is a kind of plastic processing technology. The main principle is to heat and soften the flat hard plastic sheet, then absorb it on the surface of the mold by vacuum, form it after cooling, and apply it to various industries.
Compression molding, also known as compression molding or compression molding, is the operation of first putting powdery, granular or fibrous plastics into the mold cavity at the molding temperature, and then closing the mold and pressing it to form and solidify. Compression molding can be used with thermoset plastics, thermoplastics and rubber materials.
Calendering is to pass the melted and plasticized thermoplastic through the gap between two or more parallel and counter-rotating rollers, so that the melt is stretched and stretched by the rollers to form a continuous sheet product with a certain size and quality requirements. Finally, the method of forming by natural cooling. The calendering process is commonly used in the production of plastic films or sheets.
Foam molding is the process of adding an appropriate foaming agent to foaming materials (PVC, PE, PS, etc.) to make the plastic produce a microporous structure. Almost all thermosetting and thermoplastic plastics can be made into foamed plastics, and foam molding has become an important field in plastics processing.
The winding molding process is to wind the continuous fiber (or cloth tape, prepreg yarn) impregnated with resin glue on the mandrel according to certain rules, and then solidify and demould to obtain the finished product.
Lamination molding refers to a molding process that combines multiple layers of the same or different materials under heat and pressure. Commonly used in plastic processing, but also in rubber processing.
Casting is a method of plastic processing. Early casting was to inject liquid monomer or prepolymer or polymer into the mold under normal pressure, polymerize and solidify to form a product with the same shape as the inner cavity of the mold. Nylon monomer casting appeared in the 1960s. With the development of molding technology, the traditional casting concept has changed. Polymer solutions and dispersions refer to polyvinyl chloride paste and melts can also be used for casting molding.
Drop plastic technology is to use thermoplastic polymer materials to have the characteristics of variable state, that is, to have viscous fluidity under certain conditions, and to restore the solid state at room temperature, and to use appropriate methods and special tools to spray ink on it. In the viscous flow state, it is molded into the designed shape as required, and then solidified at room temperature.
Compression molding is mainly used in the production of thermosetting plastic products. The molding is heated to melt it, pressurized and punched, then heated to cross-link and solidified, and the finished product is obtained after demoulding.
Resin transfer molding is a process in which resin is injected into a closed mold to infiltrate reinforcements and cure. This technology can effectively reduce equipment cost and molding cost without prepreg and autoclave.
This technology has developed rapidly in recent years and is widely used in aircraft industry, automobile industry, shipbuilding industry and other fields, and has researched and developed various branches such as RFI, VARTM, SCRIMP, and SPRINT to meet the application requirements of different fields.
Extrusion is a pressure processing method that uses a punch or punch to pressurize the blank placed in the die to cause plastic flow to obtain a part corresponding to the shape of the die hole or the concave and convex die. When extruded, the billet produces three-dimensional compressive stress, even if the plasticity is relatively high.
Low billets can also be extruded.
Thermoforming is a special plastic processing method that processes thermoplastic sheets into various products. A relatively special plastic processing method for processing thermoplastic sheets into various products. The sheet is clamped on the frame and heated to a softened state. Under the action of external force, it is pressed against the surface of the mold to obtain a shape similar to the surface. After cooling and shaping, it is trimmed and finished.
Hand lay-up molding, also known as hand-pasting molding and contact molding, refers to manual work on a mold coated with a release agent, that is, while laying reinforcing materials, brushing resin until the required thickness of the plastic product, and then curing and The process of obtaining plastic products by demoulding.
Laser Rapid Prototyping (LRP) is a new manufacturing technology that integrates advanced technologies such as CAD, CAM, CNC, laser, precision servo drive and new materials. Compared with the traditional manufacturing method, it has the following advantages: the replicability and interchangeability of the prototype are high; the manufacturing process has nothing to do with the geometric shape of the manufacturing prototype; the processing cycle is short and the cost is low, the general manufacturing cost is reduced by 50%, and the processing cycle is shortened by more than 70%; Technology integration to realize the integration of design and manufacturing.
Fused Deposition Modeling (FDM, Fused Deposition Modeling), this process is to extrude a filamentous material such as thermoplastic, wax or metal fuse from a heated nozzle, according to the predetermined trajectory of each layer of the part, to fix the speed for melt deposition.
CNC computer numerical control machine tool is an automatic machine tool equipped with a program control system. The control system can logically process and decode programs with control codes or other symbolic instructions, so as to make the machine tool move and process parts.
3D printing (3DP) is a kind of rapid prototyping technology. It is a technology based on digital model files and using bondable materials such as powdered metal or plastic to construct objects by layer-by-layer printing. 3D printing is usually achieved using digital technology material printers. It is often used to make models in the fields of mold manufacturing and industrial design, and is gradually used in the direct manufacture of some products. There are already parts printed using this technology.
There are many different technologies for 3D printing. They differ in the way the materials are available and are built in different layers to create the part. Commonly used materials for 3D printing include nylon fiberglass, polylactic acid, ABS resin, durable nylon materials, plaster materials, aluminum materials, titanium alloys, stainless steel, silver plating, gold plating, rubber materials
