Mechanica Technical Solutions
Home | Contact | About
Manufacturing Processes > Casting Processes > Squeeze casting

Squeeze casting

 

Process description

Combination of casting and forging. Molten metal fills a preheated mold from the bottom and during solidification the top half of the mold applies a high pressure to compress the material into the final desired shape. Also known as liquid metal forging and load pressure casting.

Materials

Typically non-ferrous metals, but occasionally ferrous alloys.

Squeeze Casting

Process variations

Pouring can be performed automatically.

Economic considerations

  • Production rates low due to mold filling for minimum turbulence.
  • Long setup times.
  • Lead time moderate to high.
  • Material utilization excellent. Near-net shape achieved.
  • High degree of automation possible.
  • Economically viable for production volumes of 10 000+.
  • Tooling costs high.
  • Equipment costs high.
  • Direct labor costs low to moderate.
  • Finishing costs very low. Used to minimize or eliminate secondary processing.

Typical applications

  • Aerospace components
  • Suspension parts
  • Steering elements
  • Brake components

Design aspects

  • Complex geometries possible.
  • Retractable and disposable cores used to create complex internal features.
  • Large variations in cross section possible.
  • Undercuts, bosses, holes and inserts possible.
  • Placing of parting line important, i.e. avoid placement across critical dimensions.
  • Machining allowances usually in the range 0.6–1.2 mm.
  • Draft angle ranging 0.1–3°, depending on section depth.
  • Maximum section =200 mm.
  • Minimum section =6 mm.
  • Minimum dimension =Ø20 mm.
  • Sizes ranging 25 g–4.5 kg in weight.

Quality issues

  • Low porosity experienced.
  • Low speed mold filling minimizes splashing.
  • Accurate metering of molten metal required to flashing.
  • Excellent mechanical properties can be obtained, similar to forging.
  • Adequate process control important, i.e. metering of molten metal, pressures, solidification times, etc.
  • Graphite releasing agent and ejector pins commonly used to aid removal of finished part.
  • Surface detail good.
  • Surface roughness ranging 1.6–12.5 µm Ra.
  • Achievable dimensional tolerances approximately ±0.15 at 25 mm, ±0.3 at 150 mm. Allowances of ±0.25mm should be added for dimensions across the parting line.

costing