The profound usage of Inconel X-750 in structural and high-pressure conditions mandates improved tribological properties. One of the methods to achieve this is through surface topography modifications. In this work, the viability of the shot blasting technique is explored to enhance the wear resistance of Inconel X-750. For this purpose, aluminum oxide particles with 80 mesh size were shot blasted on the superalloy surface at a constant pressure of 0.6 MPa. The 3D surface topography of Inconel X-750 alloy confirms substantial surface deformation and increased surface roughness after shot blasting. Furthermore, the surface characteristics of shot-blasted superalloy were meticulously examined using a string of techniques: optical profilometer, scanning electron microscope, and electron probe microanalysis. The tribological properties of Inconel X-750 before and after shot blasting were examined using a reciprocating tribometer with a ball-on-flat configuration. Results showed that shot blasting the superalloy has tremendously enhanced the wear resistance by ∼78%, which could be attributed to the reduced sliding contact area, enhanced surface hardness, and the hindrance in the transition of wear mechanism from abrasion tribo-oxidation to adhesion.

During friction stir processing (FSP), the combination of rotation and movement of the tool leads to frictional heat generation and plastic deformation at the tool-material contact surface, leading to a microstructurally refined formation region. The deformation rate in the material can be altered by varying the axial load by increasing or decreasing the tool’s plunging depth. In the present study, FSP was carried out on a pure copper plate of 3-mm thickness by varying the plunge depth from 2.3 to 2.6 mm for a tool pin length of 2.4 mm. The microstructure of the processed samples was studied by optical microscopy, and the grain size was measured by the linear intercept method. Tensile testing was carried out perpendicular to the processing direction. The grain size distribution was narrower at low axial loads and wider at the higher axial loads, measured between 1 and 120 µm. At higher axial loads, microstructure consisted of bands indicative of the heterogeneity in the deformation. The formation of bands at higher axial loads leads to improved mechanical properties. The ductility of the processed materials at higher axial loads was 16%, which was four times the increase observed at lower axial loads (4%). The formation of a bi-modal microstructure (alternating layers of fine and coarse grains) at high axial load enhanced the processed materials’ strength and ductility.

The structural response of ceramics to extreme deformation is of significant scientific and technological relevance since such conditions are commonly encountered during both processing and service. In this study, monoclinic zirconia was subjected to high-energy ball milling for extended durations of 80 h and 120 h, followed by annealing at 1000 °C. X-ray diffraction revealed a progressive increase in the tetragonal phase content with milling duration, while subsequent annealing promoted its consolidation alongside the principal monoclinic phase, resulting in a stable biphasic structure. The phase evolution is also evaluated through a Raman spectroscopy analysis and correlated with the morphology, mechanical properties, and surface area analyses. Scanning electron microscopy confirmed the preservation of nanoscale features in the milled and annealed specimens, in contrast to the unmilled sample, which exhibited pronounced grain coarsening. The combined presence of nanostructural stability and biphasic phase constitution underscores the efficacy of high-energy ball milling, in conjunction with thermal treatment, as an effective strategy to tailor the microstructure and phase stability of zirconia ceramics for advanced engineering applications.