Features of manufactured and impact failure of a layered material based on Ti-6Al-4V alloy

Structural methods for controlling the properties of a layered material (LM) based on Ti-6Al-4V alloy are presented in this work. The layered materials were manufactured by diffusion bonding. They consist of seven and thirteen sheets of the thickness about 1.5 and 0.8 mm, respectively. Two methods of assembling the sheets were used: in one case, they were stacked relative to each other so that the rolling direction (RD) in them coincided (LM of type 1), and in the other, they did not match (LM of type 2), the angle between the RD in the neighboring sheets was 0 and 90 degrees, respectively. It was found that the prismatic texture (texture with datum planes oriented perpendicular to the rolling plane) present in the as-received sheets is inherited by the layered material of type 1 that it causes the anisotropy of impact strength. Almost the same distribution of the pole density of basis in the rolling direction and in the transverse direction determines the isotropy of impact strength in the layered material of type 2. A comparative evaluation of the test results has shown that when the crack propagates simultaneously through all layers (the crack divider orientation) the impact strength value is higher for the 7-layer material when the crack propagates sequentially from one layer to another (the crack arrester orientation) it is higher for the 13-layer material. The quantitative assessment of the fracture characteristics made it possible to establish that the decrease in the impact strength of the samples tested in the crack divider orientation with the number of layers increasing is conditioned by decreasing both the crack initiation energy and the crack propagation energy. In contrast, the improvement of impact strength of the samples tested in the crack arrester orientation occurs due to the significant increasing the crack propagation energy at an insignificant decreasing the crack initiation energy.