The effect of material cleanliness on dynamic damage evolution in 10100 Cu

Two different plates of 10100 Cu (> 99.99 % Cu) were incipiently failed using flyer plate impact in a gas gun equipped with soft recovery. One plate has a grain size of 53 μm and the other, 63 μm. The cleanliness of the plates was assessed using the cold crucible melt technique. The smaller grain sized material has a number density of second phase particles about four times higher than the other material, but with a smaller mean size. The size distribution of second phase particles is well represented by a log normal distribution. The Stepanov corrected spall strength, as measured by a VISAR, of larger grain sized material is about 50 % higher than that of the other material under incipient loading conditions. The difference in spall strength between the materials decreases with increasing shock pressure. Void nucleation plays a dominant role in describing the resulting porosity distribution in the incipiently failed samples. The cause of the difference in spall strength between the plates is attributed to differences in the second phase particle characteristics of the material