Every time you drive a motor vehicle, fly in an airplane or ride a bicycle, hydroforming was likely used as part of their manufacture. Hydroforming provides a number of advantages when compared to other alternative methods of metal shaping. By learning more about what is hydroforming, understanding the significance of this process in our daily life should be possible.
The Standard Concept
Aluminum is a malleable material that is often molded using hydroforming. Two processes can be used during the hydroforming process for manipulation. The first is using high pressure hydraulic fluid to produce a certain shape with the metal. The metal (typically a flat sheet) is placed inside a container with a mold. The container is sealed off and hydraulic fluid injected until a certain pressure is achieved. This pressure causes the metal to mold to the shape of the dye. A variation of this concept involves the manipulation of a hollow tube of metal. The hollow tube is placed inside of a negative mold and fluid is injected into the inside of the tube, causing it to expand into the shape of the mold.
Low Pressure Versus High Pressure Tube Hydroforming
In tube hydroforming, two methods are typically used. The only difference between the two are the pressures used and when they are applied. In high pressure hydroforming, the tube is exposed to high pressures (typically between 1500 and 2000 bars) only after being closed in the dye of the hydraulic press. In low pressure hydroforming, the tube is exposed to a low pressure of between 120-180 bars before being closed in the dye of the hydraulic press. According to Metal Working World Magazine, “The material does not collapse, taking the die shape, but simply it is uniformly stretched (thus avoiding the corrugations of the inner surface that are instead frequently present in the high pressure method), like in a pre-forming process.”
Be sure to contact us at American Hydroformers if you have any questions about what is hydroforming.