Determination of dynamic fracture toughness of boron modified AS-CAST Ti-6Al-4V alloys

Abstract

The Ti-6Al-4V alloy is highly regarded as the dominant Titanium alloy due to its exceptional specific and fatigue strength, as well as its resistance to oxidation. These qualities make it a favored material in the aerospace industry. However, its widespread use is hindered by the significant costs involved in its wrought processing, which typically requires mechanical working at elevated temperatures beyond its β-transus temperatures to achieve a refined grain size. Recent research has demonstrated that incorporating small amounts of Boron into Ti-6Al-4V alloys aids in grain size refinement, thereby eliminating the need for extra thermo-mechanical steps in processing. Furthermore, the mechanical properties of Boron-modified Ti-6Al-4V alloys have been found to be nearly equivalent to those processed by conventional means. Given that these alloys are frequently exposed to impact loadings in real-life applications, understanding the fracture mechanisms under such high loading rates is both intriguing and essential for designing structures with improved resistanceto fracture.