The interface microstructure and tensile properties of direct energy deposited TC11/Ti2AlNb dual alloy

摘要

Direct energy deposition process based on laser and powder feeding provides powerful ability in integrated manufacturing of multi-materials components. In this work, TC11/Ti2AlNb dual alloy thin walls were prepared by direct energy deposition process. The microstructure evolution and tensile properties of the dual alloy samples perpendicular to the interface after different heat treatments were investigated. The results indicated that there were two distinct composition transition zones between these two alloys due to the dilution effect during the process. From TC11 alloy side to Ti2AlNb alloy side, the phase evolved as: alpha + beta -> alpha + alpha(2) + beta/B2 + O -> alpha(2) + beta/B2 + O -> alpha(2) + B2 + O. As -deposited materials presented better mechanical performance than other two counterparts both at room temperature and 650 degrees C elevated temperature. For all samples, the fracture positions were not located within the interface zone, indicating the good mechanical performance of the interface zone. For demonstration, a TC11/Ti2AlNb dual alloy blisk was prepared by this process. (C) 2016 Elsevier Ltd. All rights reserved.