Investigation of Anisotropy and Homogeneity in Mechanical Properties of Ti-6Al-4V Ring-shaped Material

With the continuous expansion of titanium alloy applications, titanium alloy ring materials have gradually been popularized and applied in the field of marine vessels. Therefore, to ensure the safety and reliability of ship structures during operation, it is essential to focus on the anisotropy and homogeneity of titanium alloy ring materials. This study systematically investigated the anisotropy and homogeneity of tensile properties, impact properties, and fracture toughness of Ti-6Al-4V alloy ring materials, and further analyzed the internal reasons leading to the differences in properties. Tensile properties of the ring materials exhibited anisotropy and inhomogeneity. At the same location, the yield strength of circumferential samples was higher than that of axial samples; when samples were taken from different locations, the yield strength and tensile strength of samples at the 1/2 wall thickness position were the lowest, while those at the outer surface were the highest. The impact properties of samples with notches perpendicular to the inner and outer surfaces of the ring material exhibited obvious anisotropy, and the impact properties also show inhomogeneity when samples were taken from different positions. Microstructural analysis indicated that grain size, texture, grain orientation, and twins may influence the anisotropy and homogeneity of impact properties. K_IC values of the ring material showed insignificant anisotropy and obvious inhomogeneity, with the highest K_IC values observed in samples taken from the 1/2 wall thickness position, while K_IC values of samples from the outer and inner surfaces were roughly similar.