Materials Used In Castings

Casting is broadly defined as the process of forming a substance into a specific shape using a mold, and metal casting employs a variety of casting materials and metals to create the molded end product and dates back thousands of years.Some of the metal casting processes and materials used for casting in ancient times are still in use today. There are numerous reliable and effective metal casting materials that are used for industrial purposes. The most commonly used resources are:

  • Gray iron
  • Ductile iron
  • Aluminum
  • Steel
  • Copper
  • Zinc


Gray Iron Casting

Gray iron is one of the most frequently used casting materials in industrial manufacturing. Accounting for a large portion of casting supply markets, it is a strong, versatile substance. Gray iron can be machined easily, tested for quality without using destructive methods, formulated to meet specific application requirements, and is cost-effective at high volumes. It is suited to a variety of applications, including those that require:

  • Damping or vibration control
  • High strength to weight ratios
  • Dimensional stability

Ductile Iron Casting

For processes requiring greater strength than that provided by gray iron casting, ductile iron casting may be a useful alternative. Ductile iron shares similar traits with gray iron, and thus has many of the same advantages. However, ductile iron differs from gray iron casting in the following ways:

  • Greater strength
  • Improved wear resistance
  • Stronger toughness
  • Superior ductility
  • Reduced weight
  • Reduced shrinkage
  • Lower cost

Aluminum Casting

Aluminum casting is also a widely used method, due in large part to the superior versatility of the metal. As one of only a few materials able to undergo most metal casting processes, aluminum is a relatively adaptable substance to work with. Aluminum’s corrosion resistance, high thermal/electrical conductivity, good mechanical properties and strength at high temperatures make it an effective choice for:

  • Die casting
  • Permanent mold casting
  •  Investment casting
  • Sand casting
  • Lost foam casting
  • Squeeze casting
  • Hot isotonic pressing

Steel Casting

Steel is a tough casting material well-suited for parts that will be subjected to exceptional wear, shock or heavy loads. It is useful for its corrosion resistance in aqueous environments and for applications involving elevated temperatures. Steel is often mixed with chromium, iron, and nickel to further improve its corrosion or heat resistance.

Copper Casting

A major advantage of copper as a casting material is that it offers excellent electrical conductivity. As a result, the construction industry often uses copper for electrical components. Other benefits of copper include:

  • Good malleability
  • Superior ductility
  • Good conduction of heat

However, copper and castings can be subject to surface cracking, porosity and formation of internal cavities. Consequently, it is often mixed with other metals (silicon, nickel, zinc, chromium, tin and silver) to alleviate these issues.

Zinc Casting

Zinc’s low melting point (425 degrees Celsius) makes it a suitable material for die-cast applications. It is a relatively easy alloy to cast due to its fast fill and fast cooling capabilities. In terms of cost, zinc may be an economical option for casting small, high-volume parts.

Industrial Casting Applications

Casting is used in a large number of manufacturing processes and plays an important role in construction. Many industries depend heavily on casting to create uniform products. Some of the leading markets for casting materials are:

  • Automotive and Light Truck
  • Pipe and Fittings
  • Construction, Mining and Oilfield Machinery
  • Internal Combustion Engines
  • Railroad
  • Valves
  • Farm Equipment
  • Municipal Castings

Things to Consider When Choosing Casting Materials

Selecting the proper cast and mold materials for a particular project can be an important concern. Some of the factors to consider when making a casting decision include:

  • Level of volume required
  • Cost-effectiveness
  • Melting temperature
  • Cooling speed
  • Wear resistance
  • Weight
  • Damping capabilities

Zinc is an efficient choice for die cast operations, however, its low wear resistance and durability may not be ideal for certain applications, such as those involving a high risk of corrosion or material strain. For die cast projects that focus on performance and resilience, aluminum can be a helpful option. For example, aluminum alloy is a frequently used casting material for lawnmower housings, dental equipment, frying skillets, aircraft hardware and marine hardware.

For structural applications or other tasks that emphasize strength and durability, gray iron or ductile iron may be worthwhile considerations. Gray iron can be effective for projects that require shrinkage-free, intricate castings such as those found in motor blocks. Ductile cast iron is useful for parts that stress strength and toughness, such as critical engine components (crankshafts, truck axles, disk brake calipers, etc.).

Post time: Apr-04-2023