Determination of crystallographic texture in metal sheets using ultrasound and EBSD

Abstract

The quantitative measurement of crystallographic texture through determination of the Orientation Distribution Coefficients (ODCs) can provide critical information on a sample's suitability for being utilised in a particular manufacturing process or can be used to measure changes in the microstructure of components in service. Ultrasonic techniques have been developed by previous workers that measure three of the ODCs that describe the orientation probability distribution function for an aggregate of cubic crystallites. Electron Backscatter Diffraction (EBSD), a microscopic technique that measures the crystallographic orientations of individual crystals, has been utilised to offer an alternative method to measuring the complete range of ODCs. As a technique, EBSD provides a much more detailed measurement of texture than ultrasonic measurements ever could. Ultrasonic methods are however non-destructive, can be used on components in service and are quicker in use and are less expensive to implement that EBSD measurements. EBSD is a valuable method in validating ultrasonic measurements, and can help to guide us in determining the limitations of the ultrasonic measurements. Ultrasonic measurement of texture is and will continue to be a useful approach to measuring texture but it does have its limitations for application to real samples. Equally, one has to use EBSD properly if one is to obtain accurate and representative data for the entire sample.