Strength-ductility synergy in TZM alloys achieved via particle-stimulated nucleation and precipitate coherency optimization

Abstract

Ti-Zr-Mo (TZM) alloys inherently face a trade-off between high strength and adequate ductility, but targeted second-phase particle engineering can overcome this limitation. In this study, we demonstrate that optimizing the size, coherency of second-phase particles and impurity content yields an appreciable combination of strength and ductility in a TZM alloy. Micron-scale Zr-enriched particles act as potent nucleation sites for recrystallization through particle-stimulated nucleation (PSN), refining the grain structure to approximately 1.5 μm. This refined grain structure substantially enhances alloy strength through the Hall-Petch mechanism. Simultaneously, optimized impurity management at grain boundaries alleviates grain boundary embrittlement, thereby improving ductility. Concurrently, a dispersion of nanoscale precipitates with a semi-coherent interface to the matrix provides additional strengthening. Consequently, the alloy achieves a high tensile strength (939 MPa) coupled with promising tensile elongation (27.4 %). This represents an excellent improvement over conventional TZM alloys, underscoring that tailored second-phase particle architectures and impurity control can simultaneously increase strength and ductility. The findings provide a clear microstructural strategy for designing advanced TZM alloys with superior mechanical performance.