Structural phase transformations in welding high-alloyed titanium alloy

This article investigates the change in the phase composition and structural state during the thermal cycle of welding a high-alloyed titanium alloy. It is shown that structural-phase transformations in the welded joint occurring under the influence of the thermal and deformation cycle of welding lead to the formation of metastable phases, and its subsequent decomposition can lead to ductility losses. To bring the metal of the welded joint to an equilibrium state, stabilizing annealing is required.

EVALUATION OF THE THERMAL CONDUCTIVITY OF THE TI-CU SYSTEM BINARY AND DOPED COATINGS

The temperature dependence of the thermal conductivity in the range of 25-425 °С was obtained for the Cu-Ti system binary and doped coatings formed on the titanium surface during heat treatment by contact melting . It is shown that the thermal conductivity of coatings based on alloyed titanium cuprides is higher than that on coatings based on binary titanium cuprides.

Recycling of Titanium Alloy Powders and Swarf through Continuous Extrusion (ConformTM) into Affordable Wire for Additive Manufacturing

Over the last 20 years, there has been growing research and development investment to exploit the benefits of wire deposition additive manufacturing (AM) for the production of near-net shape components in aircraft and space applications. The wire feedstock for these processes is a significant part of the overall process costs, especially for high-value materials such as alloyed titanium. Powders for powder-based AM have tight specifications regarding size and morphology, resulting in a significant amount of waste during the powder production. In the aerospace sector, up to 95% of forged billet can be machined away, and with increasing aircraft orders, stockpiles of such machining swarf are increasing. In this study, the continuous extrusion process—ConformTM—was employed to consolidate waste titanium alloy feedstocks in the forms of gas atomised powder and machining swarf into wire. Samples of wire were further cold-drawn down to 40% reduction, using conventional wiredrawing equipment. As close to 100% of the waste powder can be converted to wire by using the ConformTM process. This technology offers an attractive addition to the circular economy for manufacturers and, with further development, could be an important addition as industries move toward more sustainable supply chains.

The influence of heat treatment on the formation of the structure and the level of mechanical properties of high-alloyed titanium alloy

The paper investigates the possibility of increasing the strength of the experimental high-alloyed titanium alloy due to various methods of thermal action, leading to a change in its phase composition and intragrain structure. Changes in mechanical properties in correlation with the change in structure in the annealed, tempered and heat-hardened state are reviewed. It is shown that by controlling phase transformations in highalloyed two-phase titanium alloys, it is possible to realize high-strength state with satisfactory plastic characteristics. The optimal complex of mechanical properties is provided by heat treatment, which leads to the creation of a two-phase heterogeneous structure with a developed bimodal intragrain structure.