Metal furniture production process
1. Casting is a casting method that smelts metal, manufactures a mold, and flows the molten metal into the mold to obtain a certain shape and performance after solidification. There are many casting methods, and the most common application is sand casting. Casting methods other than sand casting are collectively referred to as special casting. Commonly used special casting methods are: investment casting, metal mold casting, pressure casting, low pressure casting, centrifugal casting, ceramic mold casting, continuous casting, etc. Casting production has the following characteristics: 1. Strong adaptability: Casting production is not restricted by the size, shape and structural complexity of parts. Castings can be as light as a few grams and weigh hundreds of tons; the walls can be as thin as one millimeter and several meters thick. ; The length can be as short as a few millimeters and as long as ten meters. In the production of large parts, the superiority of casting is particularly significant. Casting production is generally not limited by the types of alloys. Commonly used iron, steel, aluminum and copper can all be cast. 2. Low cost: Compared with forging, the cost of raw materials used in casting is low; when a single piece is produced in a small batch, the equipment investment is less, the production power consumption is less, the shape and size of the casting are very similar to the finished parts, and the consumption of raw materials and cutting processing costs Greatly reduced. However, casting production also has several shortcomings: the crystal grains of the casting structure are relatively coarse, and there are often casting defects such as shrinkage, porosity, pores, and sand holes inside. Therefore, the mechanical properties of castings are generally inferior to forgings; there are many casting production processes. The process is more difficult to control, resulting in a higher rate of rejection of castings; the working conditions of the foundry workers are poor and the labor intensity is greater. With the development of casting technology, the above shortcomings are constantly being overcome.
2. Metal pressure processing is a processing method that plastically deforms a metal blank under the action of an external force to obtain raw materials, blanks or parts with a certain shape, size and mechanical properties. Pressure processing is an important plastic forming method, so metal materials must have good plasticity. Industrial steel and most non-ferrous metal materials and their alloys can be press processed. Raw materials such as profiles, plates, wires and other materials with different cross-sections used in industrial production are mostly produced by rolling, extruding, drawing and other methods; and the blanks or finished products of various machine parts, such as metal furniture supports, etc. are mostly used It is produced by free forging, die forging and stamping methods.
3. Metal welding is a process in which two separated parts of metal form a non-detachable connection by means of the combination of atoms. The separated metal becomes a whole after welding. The atoms at the interface form common crystal grains through the processes of mutual diffusion, crystallization and recrystallization, so the joint is very strong, and its strength is generally not lower than the strength of the base material (the welded metal). Since the contact surface of the welded metal cannot be smooth and clean, rough surface, oxide film and dirt are all obstacles to welding. Therefore, during the welding process, heating, pressure, or both heating and pressure must be used to promote the contact, diffusion, and crystallization of metal atoms in order to achieve the purpose of bright bonding. Metal welding can be divided into three categories according to its process characteristics: fusion welding, pressure welding, and brazing.
2020-10-26