ABSTRACT
In this chapter, the shear strain at various depths of a low carbon steel processed by Surface Mechanical Attrition Treatment (SMAT) was measured using deformed carbide bands as internal strain markers. Gradient structures are known to produce a wide variety of interesting properties including improved wear resistance and fatigue life, and extraordinary mechanical properties. In recent years, SMAT has gained attention for its ability to generate gradient structured materials through grain refinement of the surface layer to the nanometer scale. Experimentally measuring a single component of the strain tensor is not a trivial matter. Attempts to discern the shear component of the tensor in severe plastic deformation processes have been undertaken primarily by simulation or calculation. Experimentally, an imbedded pin method has been used to measure shear in accumulated roll bonding, where the interface of the pin can be used to map the shear strain, but this is not suitable for SMAT structures.
