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A new technique has been devised to examine deformation microstructures of thin walled metal cylinders subjected to internal impUlsive loading. The cylinders are strained finite amounts but are not carried to fracture. The stressing device uses a rigid stainless steel cell as a container and an explosively driven Lucite core to produce specimens of metals and alloys that have undergone a high strain rate expansion and are in a form amenable to direct observation by transmission electron microscopy. The total strain in the specimen is controlled and loading conditions may be reproduced for comparison of different materials. This approach is particularly well suited to the detailed investigation of explosive forming processes and shock hardening phenomena in cylindrical bodies.

In a previous paper, Foltz and Murr made some preliminary observations of residual defect microstructures in cylindrically shock-loaded stainless steel tubing, and compared these observations with those of plane-wave shock-loaded stainless steel sheet samples. In the present study, detailed investigations of the defect microstructures in shock-deformed 304 stainless steel cylinders have indicated that they are nearly identical to those observed in planar shock-loaded stainless steel of essentially identical composition (each with 0.058% C); the density and formation of deformation microtwins is- related to the nominal residual strain.