Fabrication of hybrid nanocrystalline Al-Ti alloys by mechanical bonding through high-pressure torsion

This study demonstrates an approach of utilizing high-pressure torsion (HPT) to fabricate a novel hybrid material by the direct bonding of Al and Ti disks at room temperature under a compressive pressure of 6.0 GPa and with increasing numbers of HPT turns up to 50. Detailed structural observations revealed the formation of a multi layered nanostructure in the edge regions of the disks with a grain size of similar to 30 nm. X-ray diffraction (XRD) and selected area electron diffraction (SAED) confirmed the presence of three intermetallic compounds, AlTi, Al3Ti and Ti3Al, in the layered structures. Processing by HPT led to the formation of a hybrid nanocomposite with exceptional hardness (over 300 Hv) in the edge regions of the disks. Special emphasis was placed on understanding the evolution of hardness in the hybrid material. The investigation demonstrates a significant opportunity for using HPT processing to deepen the knowledge on diffusion bonding and mechanical joining technologies as well as for fabricating new and valuable hybrid nanomaterials.

Automated summary

This study presents a method of utilizing high-pressure torsion (HPT) to fabricate a novel hybrid material by direct bonding of aluminum and titanium disks at room temperature. Detailed structural observations reveal the formation of a multi-layered nanostructure in the edge regions of the disks, which leads to exceptional hardness in the hybrid material. The investigation highlights the potential of HPT processing for diffusion bonding, mechanical joining technologies, and the fabrication of valuable hybrid nanomaterials.