Metal Die Casting Parts
Introduction of Metal Die Casting Parts
Metal die casting parts is a kind of pressure components. It is a pressure casting mechanical die casting machine that uses a installed casting mold to pour liquid copper, zinc, aluminum or aluminum alloy into the inlet of the die casting machine. Machine die castings have different names in different places, such as die castings, pressure castings, die castings, aluminum die castings, zinc die castings, copper die castings, copper die castings, zinc die castings, aluminum die castings, aluminum die castings, Aluminum die-casting parts, aluminum alloy die-casting parts, etc.
Principles of Metal Die Casting Manufacturing
Die casting is a precision casting method that uses high pressure to force molten metal into a complex shaped metal mould. The die-casting machine is a pressure casting machine fitted with a casting mould, which pours the heated copper, zinc, aluminium or aluminium alloy metal into the inlet of the die-casting machine and, by die-casting, casts copper, zinc, aluminium or aluminium alloy parts of the shape and size restricted by the mould.
Die casting is defined as “the casting method of pressing a molten alloy into a precision casting mould at high temperature to produce a large number of high precision and excellent casting surfaces in a short period of time”. The United States called die casting for Die Casting, the United Kingdom called die casting for Pressure Die Casting, and the most domestic general industry is familiar with the Japanese term, called die casting. By the die-casting method of manufacturing out of the casting, it is called die castings (Die castings)
The die casting process is therefore generally only used to manufacture large quantities of products in bulk. It is relatively easy to manufacture die-cast parts, which generally require only four main steps, and the individual cost increments are very low. Die casting is particularly suited to the manufacture of large quantities of small to medium sized castings and is therefore one of the most widely used of the various casting processes. Compared to other casting techniques, die casting provides a flatter surface and has a higher degree of dimensional consistency.
Die casting materials
The main die-casting alloy materials are tin, lead, zinc, aluminium, magnesium, copper and so on. Zinc and aluminium alloys are the most widely used, magnesium and copper alloys are the next. Currently in the electronics industry with zinc, aluminium, magnesium alloy is the main.
Zinc alloys are very fluid in their molten state and have a low melting point of only 365 degrees. It can be used in various post-processing processes, such as electroplating. It was used in the mobile phone industry, but was gradually eliminated by aluminium alloys because of its large size and poor corrosion resistance. The most used is in the bathroom industry. Commonly used are alloys 2, 3, 4, 5 and 7, the most widely used being alloy 3.
Aluminium alloys are low in density but high in strength, close to or exceeding high quality steel, good in plasticity, can be processed into various profiles, have excellent electrical conductivity, thermal conductivity and corrosion resistance, widely used in industry, second only to steel. The specific weight of aluminium alloy is only about 1/3 of that of iron, so it is very important in all walks of life, especially in the light weight of aircraft, ships, cars, electronic instruments and other processes.
The Al-Si-Cu system is commonly used, the common ones being ADC12 (A383) and ADC10 (A380). There are also Al-Si, Al-Si-Mg and Al-Mg systems. Also known as aluminium-titanium alloys are made by adding titanium to the above materials, which can significantly improve the mechanical properties of the product.
Magnesium alloys are alloys made of magnesium and other elements. Its characteristics are: low density, high specific strength, high specific modulus of elasticity, good heat dissipation, good vibration dissipation, ability to withstand impact loads than aluminium alloy, good corrosion resistance to organic matter and alkali. The specific gravity of magnesium is about 2/3 that of aluminium and 1/4 that of iron, so it is widely used in electronic equipment such as mobile phones, communication equipment, automotive parts and medical devices.
The most widely used is magnesium-aluminium alloy, followed by magnesium-manganese alloy and magnesium-zinc-zirconium alloy. The most common grades used are AZ91D, AM60B, AM50A, AS41B, etc.
Die-cast parts can be manufactured as die-cast automotive parts, die-cast automotive engine fittings, die-cast air conditioning parts, die-cast gasoline engine cylinder heads, die-cast valve rocker arms, die-cast valve mounts, die-cast electrical parts, die-cast motor end caps, die-cast housings, die-cast pump housings, die-cast construction parts, die-cast decorative parts, die-cast fence parts, die-cast wheels, etc.
Divided into cold chamber die casting and hot chamber die casting
Hot chamber die casting
Hot chamber die casting refers to putting low-melting metal (zinc, tin, lead-based alloy) into the selected hot die-casting machine metal melting pool, using the circulation of the piston to inject the molten metal into the “gooseneck”, and then using the piston The process of feeding it into the mold. Has a fast cycle time to speed up the production characteristics of parts.
Cold chamber die casting
Cold chamber die casting refers to the fact that high melting point metals (aluminum, zinc alloys and a large amount of aluminum, magnesium and copper) cannot be die cast in a hot chamber die casting machine. An alternative method is to put the metal into a pre-prepared melting furnace. After melting, a precise amount of molten metal is injected into the die casting machine, and the piston is used to push the liquid metal into the production process of the prepared mold.
Advantages and disadvantages of die casting
Advantages of die-casting
- 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 die-casting, and hot chamber die-casting machine average 400 ~ 900 times per hour die-casting, high production efficiency.
- high dimensional accuracy of die casting, high surface quality. Die casting general tolerance level for GB/T 1800-2009 IT13 ~ IT15, higher accuracy can reach IT10 ~ W 1 1. surface roughness ruler 3.2 ~ 1.6um, local up to 0.8um. because of the high dimensional accuracy and high surface quality of die casting, the requirements of the die casting can be used directly, to avoid mechanical processing or less use of mechanical processing This improves the utilisation rate of the alloy and saves a lot of machining costs.
- The mechanical properties of die castings are high. The molten metal 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.
- can die-cast complex thin-walled parts. Die casting can have complex parts shape, while the wall thickness of the parts can be smaller, aluminum alloy die casting minimum wall thickness of 0. 5mm, zinc alloy die casting minimum wall thickness can reach 0. 3mm.
- die casting can be embedded in the casting of other materials parts. This can save valuable materials and processing costs, and can obtain the shape of complex parts and improve the performance of the parts, reduce the assembly workload.
Disadvantages of die casting
- easy to produce pores in die casting. Due to die-casting when the molten metal to a very high rate of filling the mould cavity, and the mould material and no permeability, the general die-casting method of production of die castings prone to produce pores. Due to the existence of pores makes the 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.
- not suitable for small batch production. Die-casting type complex, the cost is large, so generally only suitable for larger quantities of production.
- 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 life of the die use is relatively low. The current die-casting materials are mainly aluminium alloys, zinc alloys and magnesium alloys, etc., ferrous metals rarely use the die-casting method of processing.
Unique advantages of die casting
1. Compared with sheet metal parts, die casting parts can be more complex in shape, the wall thickness of the parts can be varied, a die casting can replace several sheet metal parts, thus simplifying the product structure.
2. Compared with plastic parts, die castings have advantages in terms of strength, electrical conductivity, thermal conductivity and protection against electromagnetic radiation.
3. Compared to machined parts, die castings are lighter in weight and less expensive to machine.
4. Compared with other casting methods, die casting products have high dimensional accuracy, good surface quality and high production efficiency.
Because of the above advantages and unique advantages of die casting, die casting is now more and more widely used, playing an important role in many products such as laptops, mobile phones, cameras, cars and motorbikes.
Die Casting Moulds
Die casting moulds must be made from hot work mould steel, commonly used steels are: H13, 2344, 8407, 8418, SKD61, DAC, FDAC etc.
The difference between multi-slide die-casting and traditional die-casting
Multi-slide die-casting machine is a new type of die-casting machine, it is a die-casting machine which is powered by several slider structures, it is distinguished from the traditional die-casting machine by its high speed, high efficiency and high precision.
The traditional hot chamber die casting machine is usually composed of two moulds (fixed mould and movable mould). When the die casting machine is closed, the two die sets are locked together by hydraulic pressure. The contact between the fixed die and the movable die is the sealing line. After the two die sets are joined, the molten metal flows through the manifold and into the intake cavity. To avoid air being drawn into the die cavity, it is common practice to add an overflow well and surround the finished product, resulting in a high specific gravity of the melt. The unique grinder design of the multi-slide die casting machine solves these disadvantages.
The Multi Slip Die Casting Machine utilises 2-6 separate blocks instead of the traditional two block combination, when the mould is closed the mould blocks form a complete mill to inject the molten stock, instead of the molten stock going through the manifold and flowing to, it is taken in directly from the parting line, thus reducing material consumption, eliminating burrs and manifold generation and saving energy.
Multi-slide die-casting machine and traditional die-casting machine than the advantages: breakthrough multi-axis mould design, mould structure design diversification, die surface selection flexibility, heart-shaped can be from any angle, the direction of pulling the mould, beyond the traditional mould limitations, reduce the product secondary processing process. Precise cross-guided mould base. High mould precision, combined with precision and complex parts manufacturing, mould standardisation, reduce the mould production cost.
Multi-slide die casting machine compared to traditional die casting machine Disadvantages: Multi-slide die casting machine has advantages in small parts, but has inherent defects in large parts manufacturers compared to traditional die casting machines.