Influence of the ECAP Tool Channel Geometry on the Structure and Properties of Al-3%Mg Aluminium Alloy

In this study, commercial Al-3%Mg aluminium alloy was subjected to ECAP processing using two different ECAP die configurations. The first one – conventional and the second one modified in which a part of the exit channel in the ECAP die, causes twist deformation, to impose extra shear strains to the sample. The local changes in microstructure were characterized by Light Microscopy, SEM equipped with an EBSD facility and TEM. Mechanical properties of the ECAP processed samples were compared based on hardness measurement. The results showed that when ECAP with modified die, the greater grain and crystalline refinement is possible. The microstructures exhibit high dislocation density within subgrains with non-equilibrium and Moiré boundaries. Moreover, the mechanical examinations display a significant improvement in hardness and calculated yield strength when the ECAP process is conducted using a modified die.

Mechanical and Tibological Properties of SLM AlSi10Mg Alloy Subjected to ECAP

In this study, selectively laser melted AlSi10Mg alloy was subjected to ECAP processing for the first time. Mechanical properties of the ECAP processed samples were compared based on hardness measurement, compression and wear tests. The results showed exceptional synergy of high yield strength ~382 MPa and strain to failure of ~48% of the SLM ECAP processed sample. This sample also offered approximately ~71% higher wear resistance, than an unprocessed one. The proposed novel route expands the opportunities of both technologies to produce materials with exceptional properties.

Effect of ECAP Die Angle on Mechanical Properties and Biocompatibility of SS316L

In this study, ultrafine grain (UFG) SS316L was produced using an equal channel angular pressing (ECAP) process at two different die angles namely 120° and 126°. The effect of different die angles on mechanical, corrosion, and surface properties were thoroughly investigated. Furthermore, the subsequent effect on the cytotoxicity of SS316L was investigated. The microstructure observation shows ECAP processing has produced an elongated, finer grain size at 120° than 126°. The ECAP processing also increases the hardness of SS316L. There is no change in wettability and surface roughness observed. However, the ectrochemical measurement reveals that ECAP processing improves the corrosion resistance of SS316L. The cytocompatibility of ECAPed SS316L was evaluated by both a direct and an extract methods, finding the contribution of grain refinement by ECAP processing.

THE EFFECT OF ECAP PROCESSING TO HARDNESS, SURFACE MORPHOLOGI, AND CORROSION RESISTANCE OF 6061 ALUMINIUM ALLOYS

Al-Mg-Si alloys (6xxx) has been widely used as structural materials in building and vehicles because of its excellent strength and corrosion resistance. The improvement of fine grain microstructure which can increase mechanical and physical properties become an interesting field in recent research.. Equal channel angular press is the most promising method to apply severe plastic deformation (SPD) which can produce ultra-fine grain in the bulk material without residual porosity. This study presents some experiments results on the effect of ECAP number of passes variation to the hardness, microstructure, and corrosion behaviour of Al 6061 alloys. The samples were annealed in the furnace with argon gas environment at 530°C for 4 hours and then immersed in liquid nitrogen for 5 minutes before ECAP process. The ECAP process was done with Bc route using dies with 120° of internal channel angle and pass variation of 1, 2, 3, and 4. The optimum hardness is 107.58 HRB in Al 6061 samples with 3 passes of ECAP. The increasing ECAP number of passes leads to a significant grain size reduction from 0 way pass, the grain size is around 10 µm, while for a 4 way pass, the grain size is around 2.5 µm. The corrosion resistance of Al 6061 alloys increased with the increasing number of passes in ECAP process.

Experimental and Numerical Investigation of the ECAP Processed Copper: Microstructural Evolution, Crystallographic Texture and Hardness Homogeneity

The current study presents a detailed investigation for the equal channel angular pressing of pure copper through two regimes. The first was equal channel angular pressing (ECAP) processing at room temperature and the second was ECAP processing at 200 °C for up to 4-passes of route Bc. The grain structure and texture was investigated using electron back scattering diffraction (EBSD) across the whole sample cross-section and also the hardness and the tensile properties. The microstructure obtained after 1-pass at room temperature revealed finer equiaxed grains of about 3.89 µm down to submicrons with a high density of twin compared to the starting material. Additionally, a notable increase in the low angle grain boundaries (LAGBs) density was observed. This microstructure was found to be homogenous through the sample cross section. Further straining up to 2-passes showed a significant reduction of the average grain size to 2.97 µm with observable heterogeneous distribution of grains size. On the other hand, increasing the strain up to 4-passes enhanced the homogeneity of grain size distribution. The texture after 4-passes resembled the simple shear texture with about 7 times random. Conducting the ECAP processing at 200 °C resulted in a severely deformed microstructure with the highest fraction of submicron grains and high density of substructures was also observed. ECAP processing through 4-passes at room temperature experienced a significant increase in both hardness and tensile strength up to 180% and 124%, respectively.