Formation of two amorphous phases in the Ni60Nb18Y22 alloy after high pressure torsion

Self-annealing in a two-phase Pb-Sn alloy after processing by high-pressure torsion

A Pb-62% Sn two-phase eutectic alloy was processed by high-pressure torsion (HPT) and stored at room temperature (RT) to investigate the occurrence of self-annealing. The microstructural characteristics and mechanical properties were recorded during self-annealing using scanning electron microscopy, tensile testing and nanoindentation. Processing by HPT produces a weakening effect but storage a...

Formation and growth of nanoindentation-induced high pressure phases in crystalline and amorphous silicon

Nanoindentation-induced formation of high pressure crystalline phases Si-III and Si-XII during unloading has been studied by Raman micro-spectroscopy, cross-sectional transmission electron microscopy XTEM , and postindentation electrical measurements. For indentation in crystalline silicon c-Si , rapid unloading 1000 mN/s results in the formation of amorphous silicon a-Si only; a result we have...

Numerical Analysis of Severe Plastic Deformation by High Pressure Torsion

High-pressure torsion (HPT) is a metal processing method in which the sample is subjected to a very high plastic shear deformation. This process can produce exceptional levels of grain refinement, and provides a corresponding improvement in mechanical properties. To investigate the stress and strain distribution due to HPT process finite element simulation were conducted to investigate effectiv...

Dual mechanisms of grain refinement in a FeCoCrNi high-entropy alloy processed by high-pressure torsion

An equiatomic FeCoCrNi high-entropy alloy with a face-centered cubic structure was fabricated by a powder metallurgy route, and then processed by high-pressure torsion. Detailed microscopy investigations revealed that grain refinement from coarse grains to nanocrystalline grains occurred mainly via concurrent nanoband (NB) subdivision and deformation twinning. NB-NB, twin-NB and twin-twin inter...

Pressure effects on Al89La6Ni5 amorphous alloy crystallization