Linear friction welding is a solid-state joining process pioneered by TWI that has become an established technology for several niche aerospace applications.
The method involves two parts being pushed together, one oscillating at a low frequency. This creates friction that heats the metals to a temperature at which they are able to join together. When the oscillation stops, the parts cool to form a forged-quality weld.
Linear friction welding materials has a number of advantages. It is a very consistent and fast process, taking as little as a single second to create a weld. Very little preparation of the surfaces to be joined is required: any imperfections and impurities are removed along with a layer of surface metal as flash. It requires no consumables, produces no harmful fumes that require exhausting, and due to it being a solid-state process, bypasses any of the potential issues associated with solidification, such as segregation or porosity.
How TWI can help
TWI has been refining linear friction welding for more than 30 years and continues to pursue opportunities for the technology. Our services in this area extend to the following:
- Three linear friction welding machines with an axial force capability of 250kN (25 tonnes)
- Equipment and tooling design guidance
- Development of production applications
- Batch production runs
- Weld quality assessment.
Potential applications
Linear friction welding has established itself as the primary method of fabrication of bladed disk (blisk) assemblies for aircraft turbine engines. It has great potential for other aerospace applications too, including the manufacture of aircraft structural components. Linear friction welding can create parts of comparable strength and quality to machined parts, while producing a fraction of the amount of waste – bringing substantial improvements to buy-to-fly ratios.
Other sectors that linear friction welding has the potential to benefit include automotive, shipbuilding, rail, oil and gas, energy and construction.
You can find out more about our Linear Friction Welding capabilities in our Job Knowledge section.