The process of Friction Welding has been utilized in the United States and Europe for over 50 years. Although well known to some, in general it has been a very well-kept secret. Once people completely understand the process, its benefits quickly become evident. One particular benefit is the ability to weld dissimilar materials.

A form of friction welding is known as Inertia Welding. Inertia Welding provides the increased benefits of repeatability and consistent upset length (overall length) over standard direct drive friction welding systems. This is extremely important when welding is required on both ends of the work piece as in the manufacturing of fuser and pressure rollers for the Photocopier Business.

The Process

Friction Welding is a process by which parts are loaded into the welder, one attached to the rotating spindle and one held stationary. Based on the materials, parameters are set for rotational speed, axial weld force, and time cycle to achieve the maximum weld strength and desired upset length.

With Inertia Welding, the time parameter is removed and replaced by a flywheel with a predetermined mass. This difference is significant in controlling the overall upset or overall length of components after weld. The kinetic energy stored in the rotating flywheel is dissipated as heat through friction at the weld interface as the flywheel speed decreases. An increase in friction welding force (forge force) may be applied before rotation stops.

Process Advantages

• Ability to weld dissimilar materials: process allows the joining of dissimilar metals that traditional welding does not.
• Lead times reduced: process is at least twice (and up to 100 times) as fast as other welding techniques.
• Cut raw material costs with bi-metal applications: use expensive materials only where they are necessary.
• Reduces machining labor: which in turn increases capacity and reduces perishable tooling costs.
• Wide range of part shapes: Friction welders are versatile enough to join a wide range of part shapes, materials and sizes.
• Forged quality: with a 100% butt joint weld through the contact area.
• Solidification defects do not occur: e.g. gas porosity, segregation or slag inclusions.
• Powder metal components: can be welded to other powder metals, forgings, castings or wrought material.
• Eliminates human error: with the machine-controlled process the weld quality is independent of operator skill or aptitude.
• Ecologically clean: no objectionable smoke, fumes, or gases are generated that need to be exhausted.
• Low Power requirements: are as much as 20% of that required of conventional welding processes.
• Superior strength in critical areas: with full surface welds.
• High production runs can be accomplished.
• Minimal set-up for prototype and short runs.

Applications

• Transmission parts
• Military Fuses
• Business machines
• Fuser Rollers
• Glosser Rollers
• Laminating Rollers
• Pressure Rollers
• Conveyors
• Golf Clubs
• Hand Tools
• Piston Rods for HVAC compressors, garden equipment, heavy equipment markets

Weldable Materials

A MAJOR COST SAVINGS is possible because engineers can design bimetallic parts that use expensive materials only where needed. Expensive forgings and castings can be replaced with less expensive forgings welded to bar stock, tubes, plates and the like.

Metal combinations such as aluminum to steel, copper to aluminum, titanium to copper, and nickel alloys to steel, not normally considered compatible can be joined by inertia welding. All metallic engineering materials which are forgeable can be inertia welded, including automotive valve alloys, tool steel, alloy steels and titanium. In addition, many castings, powder metals and metal matrix composites are weld-able.