Use of CMT-Surfacing for Additive Formation of Titanium Alloy Workpieces

Results are provided for a study of the additive formation of products from a high-tech heat-resistant alloy 2V of the Ti-Al-V system using deposition with a consumable melting electrode in a protective gas in a pulsed regime with a cold supply of material (CMT Advanced). Research shows that hybrid technology of multilayer CMT (Cold Metal Transfer) surfacing with layer-by-layer strain hardening makes it possible to use heat-resistant high-tech titanium alloys in order to prepare products of a given geometric shape. It is established that the different morphology of the structure of deposited layers is explained by different cooling rates in the crystallization stage and in the stage of solid state transformations: a basket- like structure is formed with a fast cooling rate, and a martensite-like plate structure is formed with slow cooling, represented by colonies of relatively parallel α-platelets. Different fineness is recorded for α-colony plates, i.e., from 200 to 500 μm, and the size of individual needles is from fractions of a micron to 100 μm. It has been established that forging makes it possible to increase deposited metal microhardness by no more than 5–7%, but the undoubted advantage of the CMT process with deformation is a significant reduction in deposited metal porosity.