Volumes of production
The process is being developed predominantly within the automotive industry for mass-production scales.
Unit price vs. capital investment
High investment costs for startup production. However, existing electromagnetic forming machines can be altered quite simply with a more powerful coil. Overall costs are reduced due to low maintenance of parts and the elimination of secondary finishing processes.
Speed
The process can cut parts up to seven times faster than laser cutting. Speeds are incredibly high (a 11/8 -inch-diameter hole can be punched in one-fifth of a second).
Surface
The main benefits of the process derive predominantly from the use of a magnetic field in place of a cutting tool (as with stamping): there is no wear or damage to any parts as no physical contact is made between the materials. As a result, the punched edges are very refined, which eliminates the need for additional finishing and in turn reduces cycle time and costs.
Tolerances
Testing has shown that the process can punch holes in stainless steel and other hardened metals, and could also be used to form shapes in metal without the need for a die or mold. This opens up entirely new opportunities within the manufacture of heavy metals, affirming the process as a valuable tool in the future of automotive and vehicle production.
Relevant materials
A range of magnetic metals (that is, the process is not suitable for use with aluminum, etc.), and significantly tough materials such as stainless steel and other hardened metals.
Typical products
The process is best suited to large panels, such as automobile doors, frames, and hoods. It is also used for home appliances, including washing machines, dishwashers, and refrigerators, etc.
Similar methods
Superforming aluminum (p.70), press forming (p.59), Industrial Origami® (p.61).
Sustainability issues
Energy consumption is likely to be very high due to the intensive pressures that are required to deform the steel sheets. However, electromagnetic forming requires no tooling or contact with the steel, which reduces material consumption through maintenance and replacement of parts during the lifespan of the machine.
Further information
http://www.fraunhofer.de/en
Metal Spinning
including sheer and flow forming
Product |
Spun |
Designer |
Thomas Heatherwick |
Materials |
brushed/polished steel or copper |
Manufacturer |
Haunch of Venison |
Country |
UK |
Date |
2010 |
These large metal spinnings perfectly illustrate the typical forms that are the result of the process, even down to the spinning lines which are clearly visible. Though these works are substantial, even larger forms are possible.
Spinning is a widely used technique for bending sheet metal. As the name suggests, the process involves a flat metal disk, known as the blank, being spun, pushed, and consequently wrapped around a rotating mandrel to produce curved, thin-walled shapes. A flat metal sheet (the blank) is first clamped against the mandrel and then both are rotated at high speed, in the same direction. The spinning metal is then pushed with a tool—which in hand spinning is sometimes called the “spoon”—against a wooden mandrel until it fits to the mandrel’s shape. The resulting part is thus a copy of the external shape of this mandrel. Several operations can be performed in one setup, and work pieces may have re-entrant profiles (undercuts). The design profile in relation to the center line is therefore virtually unrestricted, though it will be symmetrical.
Sheer and flow forming are advanced forms of spinning that can be used to deliberately alter the wall thickness of metal parts by anything up to 75 percent. It is ideal for concave, conical, and convex hollow parts.