Published on 03 December 2011
The Midlands based engineering business Thompson Friction Welding wanted TWI to make several preforms by joining large blocks of raw material to second and third blocks. The process, linear friction welding, sometimes known as solid-phase additive manufacture, allows complex shapes to be manufactured without the wastage of material normally associated with machining from one large block, casting or forging.
The merits of preform manufacture are:
- Typically such applications include components that are currently machined from solid blocks of high value materials. Linear friction welding preforms both the quantity of material which is turned into swarf, and machining costs can be drastically reduced.
- Feasibility studies in a range of titanium alloys have already shown that excellent weld properties can be achieved. The tensile and fatigue properties are comparable or even better than the parent metal.
- Existing mill annealed plate allowables, usually for thin section, can be included in component design.
- The process window for good quality LFW in titanium allows is generally very large.
- The LFW approach allows inclusion of dissimilar titanium alloys at defined locations in the component. Example parts clearly show the saving in machining of high value materials.
It is a highly repeatable process which has its roots in blisk manufacture. The development of low cost LFW machines has increased recently and the process now accommodates many more LFW applications than were available a decade ago.
To learn more about TWI's linear friction welding capability please contact us.