Strain glass transition in Nb nanowire toughened NiTiHf shape memory alloy composite wires

In this work, we successfully prepared Nb nanowire toughened NiTiHf composite wires with different diameters. The strain glass transition was found in the as-drawn 0.1 mm diameter wire characterized by the Vogel-Fulcher type frequency-dependent modulus anomaly. However, the strain glass transition was not detected in 0.3 mm diameter wires. Microstructural characterization reveals that densely distributed Nb nanowires with small diameter and discontinuous orientation impose both physical confinement and heterogeneous stress fields on the matrix, which interrupt the long-range ordered martensitic transformation, leading to a continuous, high-order like strain glass transition. This work provides a new design strategy for searching new strain glass systems.