Description:
In hydroforming, a metal blank is
formed into a desired shape with the use of fluid pressure impinging on the
blank which in turn impinges on a die that gives the blank its final shape.
Hydroforming has a number of advantages when compared to other shaping
processes, including reduced tooling cost, increased drawability, and enhanced
stability. Currently, there has been little or no use of hydroforming in the
production of composites. However, there is a need for a forming and shaping
method that can produce complex composite structures with as little wrinkling or
tearing as possible.
Description
Michigan State University’s technology
is a method to apply hydroforming manufacturing to the processing of shaping
composite materials. To produce a hydroformed composite part, a diaphragm is
lowered onto the blank and an initial fluid pressure is applied that deforms it
onto the retracted punch piece. The punch is then extended, forcing the blank
material between the punch piece and the pressurized "forming chamber" created
as the diaphragm deforms. The punch continues to extend and draw the part until
the desired depth and other dimensions are achieved. Next, the diaphragm
pressure is relieved, and the diaphragm and punch piece are retracted, leaving
the formed part to cool and be processed further. The even hydrostatic pressure
applied by the diaphragm helps prevent fiber wrinkling and other defects. In
addition, the diaphragm support also provides more uniform part thickness
control and reduces the propensity for part thinning or "necking" as is common
in other material drawing processes.
Benefits
* Higher part complexity:
The technology provides
flexible cross-section choices as well as the ability to mix materials, fiber
types, sheets, and weaves.
* Expanded part type capability:
More diverse design choices
are available due to deeper draw capability.
* Lower tooling costs:
The diaphragm-punch
arrangement avoids the need for a matched high-strength steel die set, thereby
reducing tooling requirements.
* Reduced residual stress:
Reduced post-forming and
cooling deformation.
* Lower defect rate:
Reduced wrinkling,
displacement, ruptures, and other forming defects.
Applications
* Automotive:
body/frame structures
and other metal replacement options
* Defense: metal decking/railing replacement or removable
armor
* Energy: fuel cells, membrane components, and wind
turbine blades
IP Protection
Status
U.S. patent
6,631,630
