- An alternative to die casting, forging and the “Acurad” process, with a high yield of >98%.
- Water-cooled (<60˚C) Cu-2%Be moulds coated with graphite every 50 castings. Mould life is exceptionally good.
- Fe-5%Cr hot work steel forging dies are coated with graphite before each forging and pre-heated to 250˚C using cartridge heaters. Die life in excess of 300,000 forgings.
- Medium to high production rates of 180–250 components h-1.
- Typical products include spider cranks for bicycles and small connecting rods for internal combustion (IC) engines.
- Low cost ingot feedstock is up to half the price of bar stock used for conventional forging.
- Similar materials to those used for squeeze casting, i.e. aluminium casting and forging (6082/2014A) alloys.
- Rapid cooling and grain refining lead to a fine equiaxed grain structure which imparts anisotropic properties.
- UTS, 0.2% proof stress and percentage elongation compared favourably with fully heat treated wrought alloys. Typical “Hyperforge” properties for heat treated (T6) alloys are:
Elongation at fracture
0.2% proof stress
5 x 108 Hz (MPa)
5. Fatigue and impact properties only slightly less than for wrought alloys.
- Design limitations are those of conventional forging processes, i.e. no re-entrant angles and small draft angles of approximately 5˚.
- Surface finish is dependent on die condition but is typically in the range 3.2–12.5 µm Ra.
- Dimensional tolerances of ±5 mm m-1.
- Clipping of forging leaves a “witness mark” which requires removal by finishing.
This article is a part of Manupedia, a collection of information about some of the processes used to convert materials into useful objects.