Fabrication of High Strength Hybrid Materials through the Application of High-Pressure Torsion

Abstract

It is well established that bulk nanostructured materials with ultrafine grains can be fabricated through the application of severe plastic deformation (SPD) since this is a promising technique for achieving significant grain refinement in bulk metals. Among the various potential SPD techniques, the most attractive appears to be processing by high-pressure torsion (HPT) because this leads to exceptional grain refinement and to grain sizes that are generally not achieved using other SPD procedures. This report describes very recent attempts to form metal matrix nanocomposites (MMNCs) by processing two dissimilar commercial metals, such as aluminum and magnesium alloys, through the use of HPT at room temperature. After significant evolutions in microstructure during the HPT processing, it is demonstrated that hybrid systems may be successfully fabricated having unique microstructures in the form of multi-layered structures. The evolution of small-scale mechanical properties was examined through the novel technique of nanoindentation and the improvement in plasticity was directly estimated by calculating the strain rate sensitivity after processing by HPT. These results demonstrate the possibility of using HPT processing for the fabrication of MMNCs having exceptional properties including very high strength.

Texture evolution in high-pressure torsion processing

“…Several modified HPT processing methods were proposed over the last decade such as highpressure tube twisting (HPTT) [34], tube high-pressure shearing (t-HPS) [35,36], highpressure-double-torsion (HPDT) [34], high-pressure sliding (HPS) [37], reversal high pressure torsion (RHPT) [38] and high pressure compressive shearing (HPCS) [39] in order to provide solutions to the limitations of HPT processing such as the inhomogeneity of the shear strain across the disc radius or the smallness of the sample [40]. Recently, it was demonstrated that HPT processing is an excellent tool for the consolidation of metal powders [41][42][43] and for fabricating hybrid systems in order to ultimately obtain metal matrix nanocomposites (MMNCs) such as Al-Mg [44][45][46], Al-Cu [47] and Zn-Mg [48].…”

The effect of cold rolling on mechanical properties and microstructure of aluminium 6082 T6 joint by friction stir welding process

“…Bulk materials with a high strength to weight ratio are in high demand these days, especially in weight-critical industrial applications (Ghalehbandi and Malaki, 2019). The conventional light-weight metals including aluminium, magnesium and copper are widely used for structural applications in the automotive, aerospace, and electronics industries, but improvements in the mechanical properties of these metals would be attractive for enhancing their fabrication capabilities (Kawasaki and Langdon, 2018). Al-Mg-Si alloys within situ Mg2Si reinforcing particles are attractive candidate materials for aerospace, automotive and other applications (Zhu et al, 2019).The strength of these alloys are enhanced by strain hardening or cold-working which is accomplished by cold rolling, drawing and other similar operations where area reduction is obtained during forming process (Baruah and Borah, 2020).Severe plastic deformation (SPD) was developed by Russian scientists as a new method of manufacturing bulk specimens having ultrafine grained (UFG) microstructure (Kim et al, 2004).…”