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Various severe plastic deformation (SPD) processes have been developed to produce metal tubes with ultrafine grain (UFG) structures. However, most techniques are complex and limited to working with components that are short in length to avoid tube failure during SPD processes. To overcome such limitations, this study suggests the use of an equal channel angular pressing (ECAP) process for the production of tubular aluminum alloy 6061. To mitigate plastic instability effects such as tube buckling and fracture during processing, hydraulic oil was used to fill the tube cavity. Finite element analysis (FEA) using Abaqus/Explicit 6.13 was carried out to examine the feasibility of the proposed method and deformation mechanism during ECAP. A series of investigations were performed, including: microstructure analysis, torsion, and micro hardness tests to evaluate the effects of tube-ECAP treatment. Test results indicated that the resultant 60% reduction in grain size led to significant mechanical property improvements including yield shear strength, ultimate shear strength, and microhardness. However, the ductility of the material decreased slightly for the ECAP-treated samples. To resolve this issue, a heat treatment process using the T6 method was performed, leading to a notable ductility enhancement in addition to further improvements in shear strength and microhardness. the Ministry of Higher Education, Malaysia, with high impact research (HIR) grant numbers HIR-MOHE-16001-D000001. Human Resources Program in Energy Technology of the Korea Institute of Energy Technology Evaluation and Planning (KETEP), granted financial resource from the Ministry of Trade, Industry & Energy, Republic of Korea (No. 20154030200900).

Joining cylindrical and bar-shaped components manufactured from dissimilar materials is frequently required in various industrial applications. The current study focuses on developing equal channel angular pressing (ECAP) as a severe plastic deformation process for solid state joining of tubular aluminium alloy 6061 components and SAE 1018 steel rods. The influence of using a 0.1 mm thick 60Ag–30Cu–10Sn interlayer in addition to annealing at 220, 320, 420 and 520 °C for 60 min is investigated as well. Finite element analysis (FEA) is performed in order to evaluate the deformation behaviour of the workpieces during the ECAP joining process. XRD and EDX analyses as well as nanoindentation and shear tests are carried out to evaluate the joints' characteristics. The FEA outcomes show remarkable accumulation of equivalent plastic strain with relatively low strain inhomogeneity. Moreover, the experimental results indicate that with increasing annealing temperature, joint strength exhibits improvement as well. It is also revealed that the application of an interlayer at any specific annealing temperature leads to achieving higher shear strength values. According to the results, shear strength of up to 32 MPa is feasible by having an interlayer and with subsequent annealing at 520 °C. Keywords: Dissimilar metal joining, Equal channel angular pressing, Aluminium alloy 6061, Steel SAE 1018, Ag–Cu–Sn Interlayer, Annealing

In this research work, predicting of titanium nitride (TiN) coating adhesion on AL7075-T6 is presented. First TiN was coated on Al7075-T6 in different conditions and the surfaces adhesion of TiN coated specimens were measured using micro scratch force machine. Second a fuzzy logic model was established to predict the TiN coating adhesion with respect to changes in input process parameters, DC power, DC bias voltage, and nitrogen flow rate. Finally, new five experimental tests were carried out to verify the predicted results achieved via fuzzy model. The result indicated settlement between the fuzzy model and experimental results with 95.534% accuracy.