Characterisation of thickness and crystallographic texture of sheet using non-contact ultrasonic measurements

Abstract

Significant recent progress has been made towards more complete ultrasonic characterisation of both steel and aluminium strip product. The work described below characterises important material properties of thin sheet metals using non-contact ultrasonic transducers that allow measurement of hot or moving components. The measurements are more accurate as no contact is required. Two key drivers have motivated this research:

• to assess the extent to which ultrasonic techniques have the potential to replace X-ray based measurements in the laboratory and on the production line

• the potential to achieve quantitative characterisation of thin sheet metal products: the hope is that real value can be added to sheet metal products, and hence competitiveness for the manufacturer, by providing an unsurpassed level of inline measurement.

The extremely high accuracy (sub-micrometre) thickness gauging and measurements of the crystallographic grain alignment (texture) of sheet metals that can be achieved both provide valuable information that can potentially be used to monitor the manufacturing process and reduce costs. These technologies are now ready for transfer to the marketplace, and will be made commercially available in the near future.