In-situ solute measurements with a laboratory polychromatic microfocus X-ray source during equiaxed solidification of an Al-Ge alloy

Abstract

An important tool to study dendritic growth in metallic alloys is the in-situ polychromatic X-radiography. Since solutal interaction is a dominant factor influencing dendrite growth, the determination of liquid concentrations is crucial to interpret the image data. Laboratory experiments with polychromatic X-ray sources require reference measurements of samples of known composition and thickness to convert intensities into concentrations because of the wavelength dependency of the absorption coefficient. Calibration measurements and fitted intensity functions are used to determine solutal concentrations in an Al-Ge sample without using in-situ reference samples.