Tailored sheared blanks
Tailored blanks are sheet metal blanks with either local variation of thickness or properties. When used for sheet metal formed automotive and aerospace components, they enable substantial weight and cost savings. The value of the global market for tailored blanks is estimated at $2 billion.
The most popular approach to producing tailored blanks is based on differentiation of sheet thickness in otherwise uniform material. This can be achieved by butt welding of sheets with different thickness or lap welding to create patches to create so-called tailored welded blanks (TWB). The welding technology is well established but has a disadvantage of introducing a material discontinuity, which causes problems during sheet metal forming and product exploitation. Also, some metals are not easily weldable. An alternative, newer approach is based on flexible rolling, where a roll gap changes programmatically during the process, to produce tailored rolled blanks (TRB). This approach usually leads to a long thickness transition zone.
Tailored blanks with uniform thickness are more attractive from the forming point of view. They can be produced by welding different materials of the same thickness or local heat treatment of a sheet metal to change its properties. These methods are still problematic since the former introduces a discontinuity while the latter is difficult to control.
Our new process, called Incremental Equal Channel Angular Pressing (I-ECAP), is a severe plastic deformation process addressing the problem of
short billets in conventional ECAP by separating and synchronising material feeding and deformation. Because of its incremental nature, the process is able to produce long bars, plates and sheets with refined structure, improved strength and adequate ductility. It was tested in our laboratory on aluminium, copper, magnesium, iron and titanium.
Our process has been tried as a means of changing sheet metal thickness. It can also be used to produce tailored blanks with constant thickness but with varying hardness and strength. Since the main mode of deformation during I-ECAP is simple shear, tailored blanks produced by I-ECAP are referred to as tailored sheared blanks (TSB).
- lack of welding discontinuities
- applicable to all types of metals
- ability to create tailored blanks with sharp or gradual thickness change
- ability to produce constant thickness tailored blanks
- ability to refine grain structure of the material in order to improve other properties, for example superplasticity (aluminium, titanium, magnesium) or room temperature ductility (magnesium)
- potential for cost reductions
Markets and applications
- automotive, aerospace, railway, ship building
- producers of tailored blanks
Licensing and development
This technology is protected by European (EP1861211) and US patents (US8,631,673). We are seeking commercial partners for scaling up the process and/or supporting further research into tailored sheared blanks. We also welcome approaches from companies interested in licensing our patents. In the first instance please email firstname.lastname@example.org.