Experimental Investigations on the Effect of Severe Plastic Deformation Through End Milling on X-Ray Peak Broadening and Microcrystalline Characteristics of Nimonic 263

Abstract

In the present work, the quantitative contributions of severe plastic deformation (SPD) through machining on the microcrystalline features and fatigue life of SPD processed Nimonic 263 have been investigated. X-ray diffraction line profile analysis (XRDLPA) has been executed to compute the likely makeover of microcrystalline characteristics such as crystallite size, lattice strain and dislocation density using full width at half maximum of diffraction peak, and additionally, the influences of these characteristics on fatigue life of the SPD processed samples have been analyzed. To deconvolute these characteristics, Williamson–Hall methods such as uniform deformation model, uniform energy density deformation models (UEDM) and uniform stress deformation model (USDM) are employed. The XRDLPA of machined samples has confirmed a significant broadening of peaks, due to lattice distortions and grain refinement during machining, and a plot of root mean square (RMS) of lattice strain (ε_rms) versus lattice strain (ε) has resulted in no inconsistency related to the lattice plane and crystallographic direction. Further, other related physical parameters such as uniform stress, Young’s modulus and energy density are also evaluated using UEDM and USDM models. As a result of the study, it is clear that the substantial influence comes from tool nomenclature over machining parameters.