Lattice Strain Distribution on Aluminium After Equal Channel Angular Pressing (ECAP) Process

Abstract

This study is aimed at determining the lattice strain distribution of Aluminium after having been deformed using the equal channel angular pressing (ECAP) process. The Sample is Aluminium alloys series 5052. ECAP process was conducted in steel dies at ambient temperature with Molybdenum disulphide as solid lubricant. The ECAP dies has 105( channel angle, 0 mm inner fillet radius, 5 mm outer filet radius. The dimensions of specimens are 10 mm x10 mm and 50 mm in length. Before processed with the ECAP, the specimen was grounded using diamond sandpapers (100 mesh, 240 mesh, 500 mesh and 1000 mesh) and then the specimen was annealed at 450 (C for 30 min in an electric furnace. After the ECAP process, the specimen was cut to obtain seven sample tests with 1.67 mm thickness. The hardness of the sample was measured using the Micro-Vickers hardness test, and lattice strain was analysed using XRD apparatus. Modelling with finite element was conducted to compare the experiments and the modelling results. After the ECAP process, the XRD test results showed that diffractograms have a crystal plane of , , and . From the calculation from X-RD diffraction, the highest lattice strain occurs on the centre line of the specimen. The lattice strain value in the centre, inner and outer specimens were 0.005, 0.002, and 0.003, respectively. This result was verified through both modelling and the hardness test showing that the highest hardness was located at the centre of specimens with a hardness of 111.5 Hv.