Issue 38

M. Sokovikov et alii, Frattura ed Integrità Strutturale, 38 (2016) 296-304; DOI: 10.3221/IGF-ESIS.38.40 300 As the plug moves, the relief of the fracture surface becomes rougher and the local heterogeneities of shear deformations increase due to distortion of the internal structure of the material. Figure 6 : Infrared images of the plugged hole and the flying plug. Figure 7 : Infrared images of plugging. The maximum temperature at the periphery of the hole is 49°C. In this case, one can observe the iron pieces of the projectile and grooves occurred due to friction between the rough- polished end-part of the projectile and the material. The analysis of the rough surface with the scanning electron microscope has revealed the existence of two regions of different morphology: homogeneous in the middle part of the specimen and rougher near its back surface (Fig.9a). The relatively homogeneous rough surface next to the mirror surface corresponds to the shear mechanism of deformation of the material and subsequent coarsening of the deformation structures (Fig.9b).