Preparation of ultrafine-grained Nb-1Zr alloy by increasing the time of large plastic deformation during friction stir processing

Abstract

The grain evolution mechanism of Nb-1Zr alloy during friction stir processing (FSP) was studied under three large plastic deformation conditions: high-temperature-short-time, high-temperature-long-time, and low-temperature-long-time. The niobium alloy grains can be continuously refined during processing. By increasing the time for large plastic deformation during friction stir processing, ultrafine-grained niobium alloys can be prepared with only a single pass of processing. To the best of the authors' knowledge, this phenomenon has been confirmed for the first time and can be used as an efficient processing strategy for grain refinement by FSP.