Light micrograph of plastic deformation in a polymer

Figure 5a: One of a sequence of images showing the propagation of a crack in a polymer. The tensile axis is vertical. Radial cracks propagate within the spherulites. At the same time shear bands appear in the amorphous matrix. Once the crack reaches the spherulite amorphous interface, the fracture front follows along the shear bands. Scale bar = 500 μm.
Source: Morphology of Plastic Deformation and Fracture of a Biodegradable Biopolymer. Élida Hermida1,2 and Vanesa Casariego1. 1. Institute of Technology Prof. Jorge A. Sabato, UNSAM-CNEA and Department of Materials, CNEA, Buenos Aires, Argentina. 2. CONICET, Buenos Aires, Argentina. Microscopy and Analysis  23(1):S5-S8 (AM), 2009.