Die Casting Service
For customers who need mass production of metal products/hardware parts and cost control, die casting manufacturing is definitely a good choice. Like extrusion processing, die casting is also a form of “equal material” manufacturing or forming manufacturing. The difference is that die casting requires the metal raw materials are first melted and then injected into the die-casting machine. After being formed in a high-temperature and high-pressure dies/molds, they are cooled, and some require secondary finishing like CNC machining and surface treatment. JHMOCKUP has accumulated more than decades of experience in die-casting manufacturing and dies design/mold design, and has helped a large number of customers from automotive parts, aerospace, consumer electronics manufacturers, precision instruments and other industries.
What is Die Casting?
Die casting is a metal casting process that is characterized by forcing molten metal under high pressure into mould/mold cavity. The mold cavity is created using two hardened tool steel dies which have been machined into shape and work similarly to an injection mold during the process.
Most die castings are made from non-ferrous metals, specifically zinc, copper, aluminium, magnesium, lead, pewter, and tin-based alloys. Depending on the type of metal being cast, a hot- or cold-chamber machine is used.
Casting equipment and metal molds imply huge capital costs, which often limit the
process of mass production.Manufacture of parts using die casting is relatively simple, involving only four main steps, which keeps the incremental cost per item low. It is specially suited for a large quantity of small- to medium-sized castings, which is why die casting produces more castings than any other casting process.Die castings are characterized by a very good surface finish (by casting standards) and dimensional consistency.
The traditional die casting process is mainly composed of four steps, including dies preparation, filling, ejection and shakeout, which is also the basis of various improved die casting processes. Lubricants are sprayed into the cavity during preparation. Lubricants help to control the temperature of the dies/molds as well as the casting demoulding. The dies/molds can then be closed and the molten metal injected into the dies/molds at high pressure, ranging from about 10 to 175 megapascals. When the molten metal is filled, the pressure is maintained until the casting solidifies. The push rod pushes out all the castings, and since there may be multiple cavities in an die/mold, there may be multiple castings per casting process. The doffing process involves separating the residue, including the die/ mold mouth, runner, gate, and fly edge. This process is usually accomplished by extruding the casting with a special dressing die. Other methods of sand removal include sawing and grinding. If the gate is fragile, you can directly beat the casting, which can save manpower. The excess mold opening can be reused after melting.
High-pressure injection causes the mold to be filled with materials very quickly, so that the molten metal fills the entire mold before any part solidifies. In this way, surface discontinuities can be avoided even in thin-walled sections that are difficult to fill. However, this also leads to air entrapment, as it is difficult for air to escape when filling the mold quickly. This problem can be reduced by placing vents on the parting line, but even very precise processes can leave porosity in the center of the casting. Most die castings can complete some structures that cannot be done by casting through secondary processing, such as drilling,
Advantages of Die Casting:
>Excellent dimensional accuracy (dependent on casting material).
>Smooth cast surfaces (Ra 0.8—3.2um).
>High material utilization. The material utilization rate is about 60%--80%, and the blank utilization rate is 90%.
>Thinner walls can be cast as compared to sand and permanent mould casting (approximately 0.75 mm or 0.030 in).
>Inserts can be cast-in (such as threaded inserts, heating elements, and high strength bearing surfaces).
>Reduces or eliminates secondary machining operations.
>Rapid production rates. Because of high speed mold filling, mold filling time is short, metal industry solidification is fast, die casting operation cycle speed.
>In all kinds of casting process, die casting method has the highest productivity, suitable for mass production.
>Casting tensile strength as high as 415 megapascals (60 ksi).
>Die casting fluid length is unaffected by solidification range, unlike permanent molds, sand castings, and other types.
>Corrosion rates for die castings are slower than those for sand castings due to the smoother surface of the die castings.
Disadvantages of Die Casting:
>Manufacturing in small quantities can be costly due to casting equipment and dies are expensive.
>There will be porosity/air holes in the die casting and mechanical properties will decrease.
>The porosity/Air holes can also prevent any heat treatment or welding.
>The size of die-casting parts is limited, and large die-casting parts cannot be die-casting because of the limitation of die-casting machine locking force and mold size.
>The type of die casting alloy is limited, because the die casting mold is limited by the temperature, it is mainly used for die casting zinc alloy, aluminum alloy, magnesium alloy and copper alloy.
Typical die temperatures and life for various cast materials:
>Zinc has a maximum die life upto 1,000,000 cycles with Die temperature
[C° (F°)] 218 (425) and Casting temperature [C° (F°)]400 (760).
>Aluminium has a maximum die life upto 100,000 cycles with Die temperature
[C° (F°)] 288 (550) and Casting temperature [C° (F°)] 660 (1220).
>Magnesium has a maximum die life upto 100,000 cycles with Die temperature
[C° (F°)] 260 (500) and Casting temperature [C° (F°)] 760 (1400).
>Brass has a maximum die life upto 10,000 cycles with Die temperature
[C° (F°)] 500 (950) and Casting temperature [C° (F°)] 1090 (2000).
The most common applications for Die casting:
Die casting can be made for die casting of auto parts, die-casting car engine fittings, die casting, air conditioning accessories, die-casting cylinder of engine cylinder head casting, die casting valve rocker arm, die-casting valve bearings, electrical accessories, die-casting motor end cover, die casting, die casting, die casting, pump shell shell building parts, die-casting parts, die-casting guardrail accessories, die-casting wheel parts, etc.,
Examples of Die Casting Service
To provide customers with the best quality service