Spinodal decomposition stabilizes plastic flow in a nanocrystalline Cu-Ti alloy

TL;DR

This study shows that spinodal microstructures in a nanocrystalline Cu-Ti alloy enhance strength and ductility, maintaining stability during aging and offering a way to improve ultra-fine grained alloy performance.

Contribution

It demonstrates that spinodal decomposition can stabilize plastic flow and retain ductility in nanocrystalline copper-titanium alloys, a novel approach for alloy strengthening.

Findings

Achieved high strength and ductility in Cu-Ti alloy via high-pressure torsion.

Spinodal microstructure persisted during aging, increasing yield strength.

Microstructure stabilization prevents strain softening and brittleness.

Abstract

A combination of high strength and reasonable ductility has been achieved in a copper-1.7 at.%titanium alloy deformed by high-pressure torsion. Grain refinement and a spinodal microstructure provided a hardness of 254 +/- 2 HV , yield strength of 800 MPa and elongation of 10%. The spinodal structure persisted during isothermal ageing, further increasing the yield strength to 890MPa while retaining an elongation of 7%. This work demonstrates the potential for spinodal microstructures to overcome the difficulties in retaining ductility in ultra-fine grained or nanocrystalline alloys, especially upon post-deformation heating where strain softening normally results in brittle behavior.