Response of aluminum alloys to erosive particle impacts

Erosive particle impacts can result in the high strain rate deposition of an appreciable amount of energy into the deformed volume of the target material. This energy likely causes local heating; softening or even melting has been observed in many materials. Hardening caused by the high-strain-rate deformation has also been reported for strain-hardenable materials. The effect of individual impacts on the surface of selected aluminum alloys was determined both analytically using theoretical considerations and experimentally using 343 Μm diameter tungsten carbide balls impacting at about 30 m/s and 30 deg incidence angle. After impact a mechanical properties microprobe was used to measure the hardness of both the crater bottom and material just below the original surface. Strain hardening, but no evidence of softening, was observed for two aluminum alloys.