The basis for our understanding of the ultrasonic bonding mechanism was first presented by B. Langenecker. This paper will explain Langenecker's contribution, with a description of the ultrasonic wirebonding mechanism based on his theory. Descriptions of the mechanisms that occur at the bonding interface will also be included. Recently a new theory has been presented by K. Otsuka that significa...

Cylindrical parts are widely used in industry at very different scales from rotating axis for engines to carbon fibres used in composite materials. Consequently, an increasing demand exists for their nondestructive evaluation. The laser ultrasonics technique providing a non-contact generation and detection process is suited for the study of acoustic waves in cylindrical structures. In previous ...

I would like to describe some of our programs at NASA, Langley Research Center, Hampton, VA, on the development and use of a new type of phase insensitive transducer we call an Acoustoelectric Converter, or an AEC. In the very short time I have here, I shall indicate why the AEC is significant and show some ultrasonic transmission results obtained from modified isometric attentuation scans of c...

The material science and characterization is a field concerned with inventing new materials and improving previously known materials by developing a deeper understanding of properties under different physical conditions. The properties of materials depend upon their composition, structure, synthesis and processing. Many properties of materials depend strongly on the structure, even if the compo...

This paper presents an advanced methodology for the detection of damage in aircraft composite materials based on sensor fusion two image-based non-destructive evaluation techniques. Both techniques, phased-array ultrasonics and infra-red thermography, are benchmarked aircraft-grade painted material skin panel with stringers. The sensors systems carrying out inspections have been developed minia...