Joining by forming—A review on joint mechanisms, applications and future trends

Severe plastic deformation (SPD) is effective in producing bulk ultrafine-grained and nanostructured materials with large densities of lattice defects. This field, also known as NanoSPD, experienced a significant progress within the past two decades. Beside classic SPD methods such as high-pressure torsion, equal-channel angular pressing, accumulative roll-bonding, twist extrusion, and multi-directional forging, various continuous techniques were introduced to produce upscaled samples. Moreover, numerous alloys, glasses, semiconductors, ceramics, polymers, and their composites were processed. The SPD methods were used to synthesize new materials or to stabilize metastable phases with advanced mechanical and functional properties. High strength combined with high ductility, low/room-temperature superplasticity, creep resistance, hydrogen storage, photocatalytic hydrogen production, photocatalytic CO2 conversion, superconductivity, thermoelectric performance, radiation resistance, corrosion resistance, and biocompatibility are some highlighted properties of SPD-processed materials. This article reviews recent advances in the NanoSPD field and provides a brief history regarding its progress from the ancient times to modernity. Abbreviations: ARB: Accumulative Roll-Bonding; BCC: Body-Centered Cubic; DAC: Diamond Anvil Cell; EBSD: Electron Backscatter Diffraction; ECAP: Equal-Channel Angular Pressing (Extrusion); FCC: Face-Centered Cubic; FEM: Finite Element Method; FSP: Friction Stir Processing; HCP: Hexagonal Close-Packed; HPT: High-Pressure Torsion; HPTT: High-Pressure Tube Twisting; MDF: Multi-Directional (-Axial) Forging; NanoSPD: Nanomaterials by Severe Plastic Deformation; SDAC: Shear (Rotational) Diamond Anvil Cell; SEM: Scanning Electron Microscopy; SMAT: Surface Mechanical Attrition Treatment; SPD: Severe Plastic Deformation; TE: Twist Extrusion; TEM: Transmission Electron Microscopy; UFG: Ultrafine Grained GRAPHICAL ABSTRACT IMPACT STATEMENT This article comprehensively reviews recent advances on development of ultrafine-grained and nanostructured materials by severe plastic deformation and provides a brief history regarding the progress of this field.

Nanomaterials by severe plastic deformation: review of historical developments and recent advances

The effect of annealing on the interface microstructure and mechanical characteristics of AZ31B/AA6061 composite plates fabricated by explosive welding

The aim of this contribution was to study the performance of cladded low-carbon steel (ASTM A283 Grade C) to austenitic stainless steel (ASTM A240 type 316/AISI 316) using hot-roll bonding. The mechanical and metallurgical properties of the cladded steel have been investigated before and after welding. Three weld samples with different configurations are prepared from cladded materials and, then, these joined metals were studied. Results on the microstructure, microhardness and mechanical strength were reported. Experimental studies showed that austenitic stainless steel AISI 316 (clad layer) could be cladded to low-carbon steel A283 (parent metal) with a good quality of bonding by hot-roll bonding. The bond interface of the cladded metals indicated that there is an intermediate zone between the clad layer and parent metal with heterogeneous microstructures due to the carbon diffusion. It was also found that microhardness measured from the clad layer to the parent metal showed an abrupt change adjacent to the interface due to a coarse grained soft ferritic band near the interface with larger microhardness than the adjacent metals. Tensile results revealed that the bonding was acceptable in all weld samples. It was also observed in bending tests that interfaces of bonded samples were safely carried out for some welding configurations. Toughness strength of the cladded metals at a given test temperature was found significantly higher than that of parent plate alone because of the high impact toughness of austenitic stainless steel layer. Consequently, mechanical properties of the low-carbon steel can be improved by hot-roll bonding with austenitic stainless steel.

Cladding of low-carbon steel to austenitic stainless steel by hot-roll bonding: Microstructure and mechanical properties before and after welding

Effect of high temperature annealing and subsequent hot rolling on microstructural evolution at the bond-interface of Al/Mg/Al alloy laminated composites

In this study, 7075 Al/AZ31B Mg/7075 Al laminated composites were prepared by hot roll bonding method. Microstructure and bonding strength of the experimental laminated composites, and thickness ratio of the constituent layers after hot rolling were evaluated. Effects of reduction ratio and rolling temperature on the microstructure, bonding strength and thickness ratio were also studied. Dynamic recrystallization microstructures were observed in the composite. The bonding strength decreased with reduction ratio and rolling temperature due to the increase in the grain size and diffusion layer width with the reduction ratio and rolling temperature. The maximal bonding strength of the experimental laminated composite was 66 MPa. The thickness fraction of the Mg alloy plate after hot rolling decreased with the reduction ratio and rolling temperature.

TH Yang

Papers

Microstructure; bonding strength and thickness ratio of Al/Mg/Al alloy laminated composites prepared by hot rolling

Proposal of bond criterion for hot roll bonding and its application