Abstract: Achieving precise control over β phase precipitation is crucial for obtaining ultra-high strength in metastable β-Ti alloys. However, a comprehensive understanding of how deformation products and their reversion counterparts influence β phase precipitation behavior in these exceptional alloys remains elusive. This study explores the influence of stress-induced martensite (SIM) and its reversion-induced dislocations on the β phase precipitation behavior in a metastable β-Ti alloy. After loading and reloading, SIM laths formed, and some SIM laths subsequently reversed into the β phase, introducing band-like regions with dense and parallel arranged <110> dislocations in the β phase matrix. Such dislocations resulted in a band-like area decorated with short rod-like β phase precipitates during isothermal annealing. Meanwhile, the remaining stress-induced martensite decomposed directly into β phase, forming a long β phase with a morphology similar to the original martensite. Additionally, both sides of the original SIM laths reversed during isothermal annealing, forming {332}<113>_β twins at the β/β phase interface. This divided the β phase formed in SIM laths from the β phase formed directly in the β matrix.

Key words: Titanium alloy, Stress-induced martensite, Martensite reversion, Isothermal annealing, β phase precipitation;