Role of cell orientation and crystallographic texture on the wear anisotropy of directed energy deposited 316 L austenitic stainless steel

Abstract

The microstructures and mechanical properties of components additively manufactured using the Directed energy deposition (DED) technique are distinct. DED results in complex cell morphology, meso‑structures of various sizes, and crystallographic textures, etc., which differ in their size and shape on the build plane (BP) and transverse plane (TP). The microstructure of the BP comprises a quasi-equiaxed grain structure and sub-grains with predominantly hexagonal solidification cells, in contrast to the TP, where the grains are columnar with elongated cells. These differences in microstructures often lead to anisotropy in mechanical properties, and the current study investigates the wear anisotropy of 316 L alloys fabricated using DED. Wear experiments are conducted using a Pin-on-disc tribometer on both BP and TP surfaces. The results show that BP surfaces exhibit superior wear resistance as compared to TP, and the analysis of the wear tracks and subsurface deformation regions using scanning electron microscope and Electron Backscatter Diffraction reveals that (i) the regions underneath the wear surface in TP experience severe wear, (ii) a high density of geometrically necessary dislocations is observed under the TP surface. Subsurface nano-hardness mapping reveals four distinct hardness regimes, with the deformation zone extending significantly deeper beneath TP than the BP. These findings highlight the combined roles of cell morphology and crystallographic texture on the wear behaviour of DED 316 L, offering insights for the design of microstructures that exhibit superior wear-resistance. © 2026 Acta Materialia Inc.