X-RAY MICROTOMOGRAPHY OF DAMAGE IN PARTICLE-REINFORCED METAL-MATRIX COMPOSITES

The damage which occurs on plastic straining of silicon carbide partic le-reinforced aluminium alloys has been characterised using x-ray micr otomography. The technique is used to provide density measurements as a function of strain in addition to imaging the internal structure wit h a resolution of approximate to 15 mu m. This allows a much more accu rate determination of microstructural damage in terms of void growth t han is available from measurements of density using buoyancy methods o r from elastic modulus decrease. These data can be combined with acous tic emission measurements during straining to allow damage nucleation and growth contributions to be separated.