Metal fusion bonding – Process – Using dynamic frictional energy
Patent
1996-03-15
1997-12-16
Heinrich, Samuel M.
Metal fusion bonding
Process
Using dynamic frictional energy
228 23, 1565802, B23K 2012
Patent
active
056975457
DESCRIPTION:
BRIEF SUMMARY
FIELD OF THE INVENTION
This invention relates to a method of friction welding.
BACKGROUND OF THE INVENTION
Friction welding is a solid phase joining process which has been known for over 30 years. In friction welding, heat is generated by rubbing one component against another under pressure. Once enough heat has been generated, the rubbing action may be terminated and the pressure may be maintained or increased for a period of time to promote the solid phase bond. The most common form of friction welding uses rotating motion in which a component constantly rotating in a single rotational sense with its central axis in a fixed position is rubbed against another component which is stationary.
In another known form of friction welding, arcuate friction welding, arcuate reciprocating motion is produced relatively between two surfaces to be welded together. This known technique has been employed in the prior art for joining items requiring good angular alignment, e.g. vehicle thermostat housings and motor vehicle fuel tanks.
In another known form of friction welding, linear friction welding, one component is moved in a reciprocating fashion through a small linear displacement in the plane of the joint to be made. This method has been used mainly for welding plastics.
Yet another form of friction welding is orbital friction welding. This method is a combination of linear and rotational friction welding wherein the centre of one component relative to the other component is moved around a two dimensional curve, e.g. a circle, to provide the rubbing action.
SUMMARY OF THE INVENTION
According to the present invention there is provided a method of friction welding, the method comprising forcing together two components to be welded together and providing a relative oscillatory movement between the two components to cause rubbing together of the two components to provide friction welding thereof, said oscillatory movement being caused by means, acting on at least one of the said components, which comprises a magnetostrictive transducer.
The oscillatory friction welding may comprise linear, arcuate or orbital friction welding all of which are known per se as noted above and all of which involve at least a component of reciprocating motion of one component relative to the other.
The oscillations of the oscillatory movement may have a frequency greater than 5 kHz preferably approximately or greater than 10 kHz in contrast to the low frequency of rotational friction welding employed in the prior art.
The magnetostrictive transducer may advantageously comprise at least one piece, e.g. a rod, of magnetostrictive material together with means for applying an oscillating magnetic field across the piece whereby one dimension of the piece changes in an oscillatory manner, e.g. at a frequency of 5 kHz or more. The means for applying a magnetic field may advantageously apply a fixed magnetic field upon which is superimposed the oscillatory field whereby the said piece has a constant magnetisation component and oscillation takes place in an approximately linear part of the magnetisation curve.
The magnetostrictive material preferably comprises one or more rare earth metals and one or more metals selected from Fe, Ni, Co and Mn. The rare earth metal or metals preferably include terbium and the other metal may include iron. For example, the magnetostrictive material may comprise Tb.sub.p Dy.sub.q Fe.sub.r where p is in the inclusive range 0.25 to 3.0, q is in the inclusive range 0.65 to 0.75 and r is in the inclusive range 1.8 to 2.2. For example, the material may comprise Tb.sub.0.27 Dy.sub.0.73 Fe.sub.2 which is commercially available under the Trade Mark Terfenol-D. The material may be incorporated in a binder, e.g. forming a metal matrix composite, as in Magmek 91 (Trade Mark) supplied by Feredyn Europe, Seminariegatan 30, S-752 28, Upsala, Sweden.
Where the friction welding is arcuate friction welding the transducer may cause angular movement of one end of at least one of the components in one angular direction. The oscill
REFERENCES:
patent: 3002871 (1961-10-01), Tramm et al.
patent: 3184841 (1965-05-01), Jones et al.
patent: 3581969 (1971-06-01), Bodine
patent: 3863826 (1975-02-01), Shoh
Roger Wise, The Welding Institute Bulletin, "Ultrasonic welding--the next chapter", Jul./Aug. 1991.
Jennings Howard Timothy
Wise Roger Jeremy
British Nuclear Fuels PLC
Heinrich Samuel M.
LandOfFree
Method of friction welding does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method of friction welding, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method of friction welding will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-199514