Meaning
An advanced metalworking process adjusts the velocity of the press ram during the stroke to optimize the deformation rate of the material. This variable speed forming enhances the formability of complex parts by slowing down the drawing speed at critical points where the metal is highly stressed. By manipulating the deformation speed, manufacturers can produce complex shapes from high-strength alloys that would split under conventional constant-speed pressing, reducing the reliance on secondary annealing treatments.
Material Flow
Controlling the strain rate during the press cycle prevents the material from thinning excessively or tearing in high-tension areas. In materials that are strain-rate sensitive, a slower forming speed reduces the flow stress, allowing the metal to flow more smoothly into deep die cavities. This control results in more uniform part thickness and higher structural integrity.
Press Control
Modern servo-driven presses are required to execute the precise speed profiles necessary for this process. Unlike traditional mechanical presses, which follow a fixed sinusoidal speed curve, servo presses allow the velocity to be programmed independently at any point in the stroke. This flexibility enables the creation of tailored forming profiles for each specific part geometry.
Strain Distribution
Optimization of the speed profile is achieved through finite element analysis before the tooling is manufactured. Simulations predict where high strain rates would cause failures and help designers program the appropriate deceleration zones. The finalized profile is then programmed into the press controller to ensure consistent production quality.
