Fatigue Life of Titanium Alloy Ti–6Al–4V Obtained by Additive Cold Metal Transfer Technology

Abstract

The work presents the experimental study results of the titanium alloy Ti–6Al–4V fatigue life obtained during additive manufacturing by wire-arc surfacing using the cold metal transfer welding. This additive manufacturing technology is used for fusing large-sized products in the Laboratory of methods for creating and designing systems “material-technology-construction” PNRPU. The quality of the resulting blank is confirmed by the results of chemical analysis, microstructural research and static tensile tests. Samples were cut from the deposited plate in the longitudinal and transverse direction with respect to the formation plane of the layers. Experimental studies of fatigue life were conducted in the Center of Experimental Mechanics PNRPU using Instron testing equipment. According to the test results, the dependences of cyclic durability on the level of applied stresses are obtained. It is noted that the direction of cutting samples from the deposited fragment significantly affect to the resistance characteristics of the low- and high-cycle fatigue of the additive titanium alloy VT6. It is concluded that there is a significant anisotropy of cyclic properties, which must be taken into account when designing and manufacturing products from additive materials.