Metallurgical effects on impact loaded materials

The change of microstructure is a common process in impact-loaded materials. Around the path of projectile, for example, cracks and white streaks are visible. From the point of view of protection this deformation behavior of an armor plate must be considered an undesired process. In order to investigate these streaks a specimen was designed by which it is possible - using a Hopkinson bar - to produce white streaks in a laboratory with the advantage of good reproducibility. With different materials load versus time measurements using strain gauges were carried out. Comparing these results with those of the examination of the streaks by light and electron microscopy methods a relationship could be given between the load-time-diagramm and the correspondent microstructure of the streaks. Furthermore the effects of material parameters on the intensity of deformation and the dimensions of the streaks are reported. (IFAM)