Ultrasonic 

Metal-Weld Horns

Design, Manufacturing &

Operational Care

It is vitally important to understand that the horn is specifically designed to perform a function. Changes made to the horn can greatly affect the performance, causing undue stress to the transducer and power supply. Never alter an ultrasonic horn from its original design without first consulting an experienced ultrasonic systems design engineer.

For the horn to transfer energy to the weldment, the horn must contact, and mechanically engage the upper component of the weldment. The most common method involves designing a weld pattern into the horn surface that allows the horn to grip the upper weldment component.

The pattern is designed with high ridges and low valleys. These can either have sharp points (teeth) or radiused edges (waves), and can also be machined as straight serrations or on an angle to produce individual peaks (knurls). Efficiency of energy transfer depends upon how efficiently the horn grips the weldment. Design issues of the weld pattern are based on the hardness, thickness and size of the material being welded. Wear on the weld pattern is inevitable and in time the tool will need to be resurfaced or replaced.

To ensure maximum tool life, ultrasonic metal weld horns are made from very hard, durable steel alloys, or in the case of replaceable tip horns, high-grade titanium. The specific metal used for a horn is determined by the application. Horns are heat treated to exact specifications. This maximizes durability but still allows enough elasticity for the tool to function efficiently. Following heat-treating, horns undergo specialized surface finishing that maximizes tool life. 

As the ultrasonic metal weld horn serves as part of the weldment clamping mechanism, the horn, usually mounted in a cantilevered fashion, must be designed to accommodate the forces exerted. This could be a few ounces or hundreds of pounds per square inch, depending on the application. So as not to diminish the horns load-bearing capabilities, extreme care is required in the design, manufacture and heat-treat stages of fabrication.

Full-wave Air Bag Horn