Friction Welding is a “solid-state joint process that produces coalescence of materials under compressive force contact of workpieces rotating or moving relative to one another to produce heat and to plastically displace material from the faying surfaces.”*
Used in the United States and Europe for more than 50 years, friction welding has been a well-kept secret. Sometimes it is referred to as spin weld or spin welding, because one part is rotated in process. As customers learn and understand the process, benefits become clear.
The ability to create near-net shape blanks offers manufacturers an opportunity to reduce material consumption and shorten machining cycle time. Joining dissimilar metals like stainless steel alloys to other metals provides unique design flexibility.
Computer controlled Direct-Drive Rotary Friction Welding: provides continuous speed control through the cycle, and stops according to a computer parameter developed specific to the part.
Inertia Friction Welding: this uses part rotation under pressure to heat the faying surfaces.
* The Friction Welding Process was formally defined by the AWS on Oct 15, 2008, in the Recommended Practices AWS C6.1 for the Welding Industry.
Is the weld process computer controlled for repeatability and quality assurance?
Yes. Hand-set manual controls can introduce variables into the process that prevent repeatability from lot to lot over time.Why AFW? Learn More
Using this quality approach ensures repeatable consistency for each additional weld produced on the machine. The results are represented visually on the Playback Graph shown below the three steps.
One component is positioned in a stationary clamp. The second part is positioned in the rotating spindle, which is then brought up to a pre-defined rotational speed (blue line on graph). At the right moment, pre-defined axial force (red line on graph) is applied.
These conditions are maintained for a predetermined time. The second step of pressure is applied (second step on red line on the graph at about 1 seconds in this example) until the desired temperatures and material conditions exist. It’s during this stage that the two materials are plasticized (become malleable). The green line signifies measurement of “length loss” and triggers the stopping point when the part reaches planned Overall Length.
Rotational speed is stopped. Then increased axial force (third step in the red line at 9.5 seconds) is applied to create “forge pressure” for another predetermined time – completing the weld. This provides molecular bonding and grain refinement through the weld zone.
Shows the record of weld parameters applied in the Stage 1-2-3 images above.