Q&A: Tube Forming

List of Questions

What tube forming shapes can be done?
What tube materials can be formed?
Why use Magnepress instead of a hydraulic or mechanical press?
Why use Magnepress instead of hydroforming?

For answers to more general questions, click here.

Answers

What tube forming shapes can be done?

Lots of them. Click here for some examples.   Magnepress has formed tubes as small as 1 cm diameter and as large as 60 cm diameter.

What tube materials can be formed?

Any highly electrically conductive metal is a great candidate; these include aluminum, low-carbon steel, and copper.  Less conductive metals, such as stainless steel, can be formed using either: 1) more energy, or 2) an aluminum, steel, or copper "driver" to move the stainless steel.  The driver can then be either removed or left on as an integral part of the assembly.

Why use Magnepress instead of hydraulic or mechanical pressing?

Lots of reasons.  Here are the five most important ones:

1) Radial forming. Any time you need to form a round part radially inward (or outward), the radial direction of the electromagnetic forces is ideal.

2) Aluminum.  In the automotive and other industries, there is interest in using more lightweight materials, such as aluminum.  Unfortunately, despite considerable development effort, adequate formability is not yet available for many aluminum materials.

Magnetic pressing, however, can form aluminum into shapes that usually are impossible to form using conventional metal forming methods without shearing the aluminum tube.

x_EMF_formability.gif (6675 bytes)Magnetic pressing produces a phenomenon called Hyperplasticity. Hyperplasticity results from inertial stabilization of material failure modes and permits dramatic increases in strain to failure.
Hyperplastic formability of structural aluminum alloys, via magnetic pressing, can cause these alloys to have higher formability than drawing quality steels. This is illustrated in the graph, where data collected from electromagnetic metal forming experiments on AL6061-T4 are plotted on a traditional forming limit
diagram against conventionally formed steel and aluminum sheet.

3) Springback is reduced or eliminated under the dynamic forming conditions achieved with magnetic pressing. This has obvious benefits with respect to product precision and quality.

4) Reduced tooling costs. The magnetic forces act as the "punch" in a punch & die set, so you only need to make the die.

5) Small size and high flexibility of a Magnepress manufacturing cell. While every application is different, Magnepress manufacturing cells are typically dwarfed by a comparable hydraulic press. Magnepress manufacturing cells take up less factory floor space and can generally be moved from place to place with a small motorized forklift. Installation time and changeover time are much shorter than for comparable hydraulic presses.

Why use Magnepress instead of hydroforming?

Magnetic pressing allows faster production rates than hydroforming.