Metal stamping and die casting are relatively common metal processes, but the machines they use are different, and the manufacturing process is completely different; also the materials used are also completely different, so how do we distinguish them? What are the characteristics of each of them?
What is metal stamping?
Metal Stamping processing is a processing technique in which the pressed sheet is directly stressed and deformed in the die to obtain a certain shape with the power of conventional or special stamping equipment; the die used for stamping is called a stamping die; the stamping die is a special tool for batch processing of stamped parts from raw metal or non-metallic materials; the stamping die is crucial in the processing of stamped parts.
Stamping processing has many unique advantages both in terms of technology and economy; mainly the advantages of high production efficiency, easy operation, easy mechanization and automation, etc
Types of metal stamping dies
1. Punching dies, dies that make material separation along closed or open contour lines. Such as often see the die inside the drop die, punching die, cut off die, cutting die, cutting edge die, cutting die, etc., these are to play the role of punching, so collectively referred to as punching die.
2. Deep drawing die is a die that uses the die to pull the material into an open hollow part, or make the hollow part further change its shape and size.
3. Forming die, is the blank or semi-finished workpiece according to the shape of the convex and concave die directly copy forming, and the material itself only produce local plastic deformation of the mold. Such as expansion die, indentation die, flaring die, undulation forming die, flanging die, shaping die, etc.
4. Riveting die is to use external force to make the participating parts connected or lapped together in a certain order and manner, thus forming a whole.
1. Single punching die, which is the simplest type of die, and it is a die that can be formed in a single process, and only one stamping process is completed in one press operation.
2. compound die, which has only one process and action, and completes two or more hardware stamping processes in the same process in one action of the press.
3. Continuous die, which is also called progressive die by some masters, is one of the more difficult dies. It is a die that has two or more processes at the same time by using automatic material feeder, and completes two or more stamping processes one by one in different processes in one press operation.
4. Transfer die, which combines the characteristics of single process die and continuous stamping die, uses robotic transfer system to achieve rapid in-die transfer of products, which can greatly improve the production efficiency of products, reduce the production cost of products, save material cost, and have stable and reliable quality and easy die maintenance.
How do you know which stamp to use?
What is stamp die?
Stamping dies are a special process equipment for processing materials (metal or non-metal) into parts (or semi-finished products) in cold stamping process, called cold stamping dies (commonly known as cold punching dies). Stamping, is a pressure processing method that uses a die mounted on a press to apply pressure to a material at room temperature to produce separation or plastic deformation to obtain the desired part.
Which materials suitable used for metal stamp die?
The reason need lubricant in metal stamping
In general; in the process of stamping; strong friction occurs between the shearing surface of the plate and the working surface of the die; so it is necessary to use a lubricant with good performance; which can form a tough lubricating film with pressure and heat resistance on the metal surface; separating the shearing surface of the plate and the working surface of the die; so as to reduce friction and cool down the temperature; and achieve the purpose of improving the life of the die and stabilizing the quality of the shearing surface. In the process of drawing; bending; forming processing; the general temperature rise is not much; improve the work-piece finish; improve product accuracy, save the cost of mold improvements. It is for this reason that stamping lubrication is necessary in cold forging and stamping.
Does stamped steel rust?
Because the oxygen in the air will oxidize the iron in the steel into iron oxide (i.e. rust); steel will be oxidized; but the degree of oxidation varies; for example stainless steel be oxidized for a long time ; the surface can be galvanized; oiled; painted and other means to prevent rust.
Strength of Die Casting
1. High production efficiency, the production process is easy to realize mechanization and automation. General cold chamber die-casting machine average 50~90 times per hour; while the hot chamber die-casting machine average 400~900 times per hour, high production efficiency.
2. High dimensional accuracy of die casting, high surface quality. The general tolerance level of die casting is IT13~IT15 in GB/T1800-2009.
3. The mechanical properties of die-castings are higher. Metal melt in the die-casting mold cooling rate; and crystallization under pressure; so in the die casting near the surface of a layer of fine grains; dense organization. Strength and hardness are higher.
4. Can die-casting complex thin-walled parts. Die castings can have complex parts shape; while the wall thickness of the parts can be smaller; aluminum alloy die casting minimum wall thickness of 0.5 mm; zinc alloy die casting minimum wall thickness can reach 0.3 mm.
5. Die casting parts can be embedded in the casting of other materials; This can save valuable materials and processing costs; and can obtain the complex shape of the parts and improve the performance of the parts; reduce the assembly workload.
Strength of Metal stamping
(1) The accuracy of the stamped parts is guaranteed by the die and has the same characteristics of one mold; so the quality is stable and interchangeability is good.
(2) Due to the use of mold processing; it is possible to obtain parts with thin walls; light weight; good rigidity; high surface quality and complex shapes that cannot be manufactured by other processing methods or are difficult to manufacture.
(3) Press processing generally does not need to heat the blank; and does not cut a lot of metal like cutting processing; so it not only saves energy; but also saves metal.
(4) For ordinary presses can produce dozens of pieces per minute; while high-speed presses can produce hundreds or thousands of pieces per minute. Therefore, it is a high-efficiency processing method.
Since the stamping process has the above outstanding features, it is widely used in various fields of national economy; For example; stamping process is used in industries such as aerospace; machinery; electronic information, transportation, weapon, daily-use electrical appliances and light industry. Not only is it widely used in industry; but also every person is directly connected with stamping products every day; Stamping can make small precision parts in clocks and instruments, and can also make large covering parts for automobiles and tractors. Stamping materials can be made from ferrous and non-ferrous metals as well as certain non-metallic materials.
The weaknesses of die-cast and Metal stamping
The weaknesses of Die Casting
1. easy to produce pores in die casting. Due to die-casting molten metal to fill the mold cavity at a very high rate, and mold material and no permeability, the general die-casting method of production of die castings are prone to pores. Due to the existence of pores make die casting can not be heat treatment methods to improve the strength and use at high temperatures; at the same time, the machining allowance of the parts can not be too large, otherwise it will remove the die casting surface hardening layer, making the surface near the pores exposed die casting surface.
2. Not suitable for small batch production. Die-casting type complex, large cost, so generally only suitable for larger quantities of production.
3. Die casting high melting point alloy when the die life is low. Some metals (such as copper alloy) melting point is very high, the die-casting material resistance to thermal deformation and thermal fatigue strength requirements are very high, the die life is relatively low. At present the die casting material is mainly aluminum alloy, zinc alloy and magnesium alloy, etc., ferrous metal rarely use the die-casting method processing.
The Weakness of Metal stamping
Noise during stamping process.
Vibration two public hazards
Which is better die casting or stamping?
Die-casting is the use of die-casting machine to form the solution at high speed, the advantage is that it can do more complex shape products; while stamping is the use of punching machine to punch out solid objects, can only do more simple shape, a single product.