Linear Friction Welding

The Linear Friction Welding Process

Up until now, friction welding could only be used on joints that had at least one round part but Thompson’s innovation means the process can be used on almost any shape. The advantages of this solid state process also mean that similar and dissimilar materials such as aluminium and copper can be completely joined, no filler material is needed and the parts do not melt so better parent material properties can be achieved.

Linear friction welding works on the basic principles of rubbing 2 pieces of material together until the surface gets hot enough to become plastic and join together. This principle has been used in rotary friction welding by Thompson for over 50 years where one part is spun against another, heat is produced and the parts are forced together. The basic parameters mean that oscillation replaces rotation but the remaining characteristics are very similar to rotary welding.

Whatever the size of the part, the weld times are similar in speed because the linear process, unlike the rotary method, ensures that friction occurs throughout the weld surface The largest linear friction weld undertaken by Thompson to date had a weld time of around 4 seconds.

The flash of excess material formed during the weld will expel from the joint line in an even plane and show the number of oscillations that have occurred during the weld. This can be removed by hand or automatically on the machine.

Check out http://www.linearfrictionwelding.com/ for more information