Evaluation of mechanical properties of nano-structured A16061 synthesized using machining

Abstract

This work focuses on the synthesis of nano-structured A16061 using machining under plane strain and evaluation of its mechanical properties. It discusses an unusual application of the machining process by using it as a severe plastic deformation (SPD) process to develop nano-structured or ultra-fine grained materials. Chips obtained from this process show higher hardness than the bulk material which is in agreement with results reported in existing literature. Chips with minimum curvature have been obtained using restricted contact tool and extrusion-machining processes. Hardness of the straight chips obtained by the stated methods, though higher than the bulk material, was less than the hardness of the curled chips obtained from conventional orthogonal machining. Furthermore, hardness of the chips obtained using tool with restricted contact length of 0.6mm showed lesser variation. Hence they were used to prepare samples for the tensile test. A novel method was used to prepare small test specimens from chips to measure tensile strength. Specimens made from the chips had higher ultimate tensile strength (53%) and yield strength (85%) than that of bulk material. Improvement in strength was accompanied by a reduction in ductility (58%) for chips as compared to bulk material. It was observed that for both the chip and the bulk material, the reduction in gauge length leads to lower values of Young's modulus showing size effect. © The Society for Experimental Mechanics, Inc. 2013.