We produce zinc die casting parts from a few grams to more than 100 pounds with superior quality ready for assembly. we offer a broad range of zinc die casting surface finishing including powder coating, e-coating, shot blasting, chrome plating, and bright finish. The industries ForceBeyond serves include automotive, food dairy, machinery, medical, plumbing, watering, mining, petrochemical, electrical, energy, aerospace, submarine and others.
What Is Zinc Die Casting? Zinc die casting is a metal casting process characterized by pressuring molten metal into the mold cavity. The mold cavity is created using two hardened tool steel molds that are machined to the net shape or near net shape of the zinc die casting parts. Zinc die casting process allows products to be made with high degree of accuracy and repeatability. The Zinc die casting process can also produce fine details such as textured surfaces or names without requiring further processing.
How are Zinc Die Castings Made? Steel dies capable of producing tens of thousands of zinc castings in quick succession must be made in at least two sections to allow the castings to be removed. These parts are firmly mounted in the machine and are arranged so that one is stationary (fixed die half) and the other one is movable (injector die half). To begin the casting cycle, the two mold halves are clamped together by a die-casting machine. Molten zinc alloy is injected into the mold cavity and rapidly solidified. The mold half is opened and the zinc casting is ejected. Zinc die casting molds can be simple or complicated, with movable slides, cores or other parts, depending on the complexity of the casting.
To date, the complete cycle of zinc die casting has been the fastest cycle to produce precision zinc parts. This is in stark contrast to sand casting, which requires new sand molds for each casting. Although the permanent mold process uses iron or steel molds instead of sand, it is much slower and less precise than zinc die castings.
| Zinc Casting Metals | ||||||||
|---|---|---|---|---|---|---|---|---|
| % | Zamak 2 | Zamak 3 | Zamak 5 | Zamak 7 | ZA 8 | ACuZinc5 | EZAC | ZA 27 - Zinc Aluminum |
| Aluminum | 3.5-4.3 | 3.5-4.3 | 3.5-4.3 | 3.5-4.3 | 8.0-8.8 | 2.8-3.3 | 25.0-28.0 | |
| Copper | 2.5-3.0 | 0.25 | 0.75-1.25 | 0.25 | 0.8-1.3 | 5.0-6.0 | 2.0-2.5 | |
| Magnesium | 0.02-0.05 | 0.02-0.05 | 0.03-0.08 | 0.005-0.02 | 0.015-0.03 | 0.025-0.05 | 0.01-0.02 | |
| Iron (max) | 0.1 | 0.1 | 0.1 | 0.075 | 0.075 | 0.075 | 0.075 | |
| Lead (max) | 0.005 | 0.005 | 0.005 | 0.003 | 0.006 | 0.005 | 0.006 | |
| Cadmium (max) | 0.004 | 0.004 | 0.004 | 0.002 | 0.006 | 0.004 | 0.006 | |
| Tin (max) | 0.003 | 0.003 | 0.003 | 0.001 | 0.003 | 0.003 | 0.003 | |
| Zinc | Bal. | Bal. | Bal. | Bal. | Bal. | Bal. | Bal. | |
| RoHS Compliant | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ |
Zinc alloys compete in the marketplace with other materials and diecasting competes with other processes to be the manufacturing route for a multitude of parts. There are many examples of zinc alloy diecastings being specified in replacement for aluminium diecastings (pressure and gravity), plastic injection mouldings, machined brass and steel, pressed steel assemblies, and cast iron. The advantages that zinc alloy diecastings show over these materials and processes that have lead to the substitution are listed below.
Zinc Alloy Diecastings vs Aluminium Diecasting
·Better precision
·Smaller draft angles
·Smaller and longer cored holes
·Much longer tool life
·Thinner wall sections possible
·Superior tensile strength and elongation
·Far superior impact strength
·Better machinability
·Better formability
·Lower casting costs
·Superior pressure tightness, no need to impregnate
·More finishing options
·Non sparking
Most aluminium diecasting alloys are made from scrap. Their cost per unit volume is generally lower than zinc alloys, which are high purity materials. They are lighter than zinc alloys and more capable of withstanding continuous stresses at elevated temperatures. However they can normally only be pressure diecast using the cold chamber process. Cold chamber diecasting is less productive than the hot chamber process used with zinc alloys, especially at the smaller end of diecasting machine sizes. In consequence the cost of a zinc alloy diecasting is frequently lower than that of an aluminium alloy diecasting especially for smaller components. When the other advantages of zinc alloy are factored in, such as the ability to accurately cast components to finished dimensions and hence avoid machining, and the much longer die life (around 5 times longer than for aluminium) the cost competitiveness of zinc alloy moves much further up the casting size range. In addition the superior formability and machinability of zinc confers cost advantages in finishing and assembly operations.
Zinc alloy diecastings are much more often pressure tight than those diecast from aluminium alloy. This means that fluid-handling devices made in zinc alloy are much less likely to leak than those made in aluminium. Also finish machining is more often required for aluminium diecastings, which tends to expose the porosity that causes the leaks. Hence it is normal for aluminium diecastings to be impregnated when they are used in such applications, adding further cost.
