Abstract
AbstractUltrafine-grained (UFG) materials exhibit significantly enhanced mechanical properties. This has brought renewed attention on the use of large strain or severe plastic deformation as a means for achieving microstructural refinement in metals and alloys. Large plastic strains imposed in a machine chip result in significant microstructural refinement, including the creation of UFG and nanocrystalline materials. It looks to be an economical route for realizing nanocrystalline materials. In the present study, small-angle neutron scattering (SANS) was employed to investigate the modifications in the microstructure of the chips produced via machining. Double crystal-based medium resolution SANS instrument has been used for this purpose. Significant scattering intensity at small enough angles reveals the presence of mesoscopic density fluctuations produced because of the machining. Atomic force microscopy images also corroborate the existence of such small length scale density fluctuations.
Highlights
It has been proved by time and again by researchers that nanocrystalline materials have enhanced mechanical properties in terms of hardness and strength over the bulk materials
Fine microstructure, composed of grains even smaller than 100 nm, is found to result from chip formation in commercial steel and brass due to the induced shear strain leading to large strain deformation
The machined chips exhibit a remarkable increase in the hardness as compared with the measured bulk hardness values in both materials
Summary
It has been proved by time and again by researchers that nanocrystalline materials have enhanced mechanical properties in terms of hardness and strength over the bulk materials. The availability of large volumes of metal chips, as bi-products either from existing manufacturing operations or from specific chip-making processes, offers opportunities to create nanocrystalline materials with mechanical properties that are influenced by the ultrafine-grained microstructure of the chips. The production costs for nanocrystalline materials created using the machining-based deformation processes are much less than those of conventional methods (Iglesias et al, 2008). This extremely fine microstructure is difficult to image without the use of Transmission electron microscopy (TEM) or Field emission-Scanning electron microscopy (FE-SEM). Investigations were carried out on the chips through SANS along with Scanning electron and Atomic force microscopy (AFM), followed by mechanical characterization through shear strain and microhardness testing
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
