Die Casting

Die Casting & Sand Casting

Alloys of aluminum are used in Die Casting more extensively than alloys of any other base metal. In the United States alone, about 2.5 billion dollars worth of aluminum alloy Die Casting is produced each year. The Die Castingprocess consumes almost twice as much tonnage of aluminum alloys as all other casting processes combined.

Die casting is especially suited to production of large quantities of relatively small parts.Aluminum Die Casting weighing up to about 5 kg are common, but castings weighing as much as 50 kg are produced when the high tooling and casting-machine costs are justified.

Typical applications of Die Casting aluminum alloys include:

• Alloy 380.0 - Lawnmower housings, gear
• Alloy A380.0 - Streetlamps housings, typewriter frames, dental equipment
• Alloy 360.0 - Frying skillets, cover plates, instrument cases, parts requiring corrosion resistance.
• Alloy 413.0 - Outboard motor parts such as pistons, connecting rods, and housings
• Alloy 518.1 - Escalator parts, conveyor components, aircraft and marine hardware and lit tings.

With die casting, it is possible to maintain close tolerances and produce good surface finishes. Die castings are best designed with uniform wall thickness: minimum practical wall thickness for Aluminum Die Casting is dependent on casting size.

Die Casting are made by injection of molten metal into metal molds under substantial pressure. Rapid injection and rapid solidification under high pressure combine to produce a dense, fine-grain surface structure, which results in excellent wear and fatigue properties. Air entrapment and shrinkage, however, may result in porosity, and machine cuts should be limited to 1.0 mm to avoid exposing it.

Aluminum alloy die castings usually are not heat treated but occasionally are given dimensional and metallurgical stabilization treatments.

Die castings are not easily welded or heat treated because of entrapped gases. Special techniques and care in production are required for pressure-tight parts. The selection of an alloy with a narrow freezing range also is helpful. The use of vacuum for cavity venting is practiced in some die casting foundries for production of parts for some special applications.

Approximately 85% of aluminum alloy die castings are produced in aluminum-silicon-copper alloys (alloy 380.0 and its several modifications). This family of alloys provides a good combination of cost, strength, and corrosion resistance, together with the high fluidity and freedom from hot shortness that are required for ease of casting. Where better corrosion resistance is required, alloys lower in copper, such as 360.0 and 413.0 must be used.

Alloy 518.0 is occasionally specified when highest corrosion resistance is required. This alloy, however, has low fluidity and some tendency to hot shortness. It is difficult to cast, which is reflected in higher cost per casting.

 Dongrun Sand Casting Capabilities: Sand Casting, Aluminum Sand Casting, Gravity Die Casting, Aluminum Die Casting