New developments in advanced welding
Applications of ultrasonic welding
The applications of ultrasonic metal welding are widespread, but have greatest use in all aspects of electrical and electronic connections as found in several industries including electrical, automotive, medical, aerospace and consumer goods.
Thus, in the automotive and trucking industries, wire harnesses serve to distribute electrical signals and power to locations throughout the body structure, and require multiple branches and consolidations of braided and solid wires of various sizes. Similar applications, although on a smaller scale, are found in the appliance industry. Figure 9.14 is an example of a typical consolidation of several leads to a common junction, while Fig. 9.15 shows various multiple wire junctions common in wire harnesses. Sensor terminations, contact assemblies, braided wire connections and buss bar terminations are all examples of connections found in the automotive and trucking industries. Electric motors, field coils, transformers and capacitors are other examples where ultrasonic welding is used in their assembly. The use of ultrasonic micobonding for microelectronic interconnections remains one of the most extensive uses of ultrasonic welding.
Battery and fuel cell manufacture uses ultrasonics to make various joints
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9.14 Multiple wire to single terminal (source: Telsonic). |
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9.15 Various wire harness multiple wire junctions (source: Telsonic). |
in these products, involving thin gauge copper, nickel or aluminum tabs, foil layers, or metal meshes and foams. Both spot and seam welding are widely used.
Packaging applications are another field where ultrasonic welding is applied widely using seam, torsion or conventional spot welding systems. For example,
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Fig. 9.16 Ultrasonically welded aircraft access panel (source: Sonobond). |
seam welding is widely used to seam foil food and cooking pouches hermetically and also finds application for splicing foil rolls during their manufacture. Torsion welding is used to seal a wide variety of cylindrical containers, where the contents may be highly reactive or heat sensitive (e. g. air bag igniters), as well as making stud weld attachements. Other packaging uses include sealing of tubes in the refrigerant and air conditioner industries.
A future trend in the use of ultrasonic welding will be in structural automotive and aerospace applications, joining thin gauge sheet aluminum and other lightweight metals. The feasibility of such uses has been demonstrated for closure panels in both helicopters and aircraft. Thus, an access panel tested for use on a fighter aircraft is shown in Fig. 9.16, where 1.6 mm inner and outer 7075 T6 aluminum skins have been ultrasonically welded into a panel of approximately 0.8 m x 0.6 m.
