Laser ultrasonic monitoring of aluminium alloy microstructural evolution

The laser ultrasonic monitoring of aluminium alloy microstructural developm ent during thermal processing is demonstrated. This monitoring is based on the ability to measure the differential ultrasonic attenuation in alloy sys tems. Differential attenuation is related to anelastic physical processes w hich are active during microstructural evolution. For the aluminium alloys studied, these anelastic effects derive from alloying species solution and mobility. Methods have been outlined for separating processes which affect the physical properties but are not related to microstructural changes from those properties which are linked to microstructural evolution. (C) 1998 K luwer Academic Publishers.