| Popis: |
In this work three types of nickel-based alloy products were obtained by wire-feed electron beam additive technology. Optimal values of wire-feed electron beam additive technology parameters were selected to ensure the formation of defect-free structure. It was found that the value of the heat input should be adjusted not only as the product height increases, but also during the formation of a single layer. This peculiarity is connected with different values and directions of temperature gradient at the beginning, in the middle and at the end of one layer. The presence of epitaxial directed growth of dendrites is explained by the fact that when a new layer is deposited, the already crystallized material is remelted repeatedly, and the underlying layers undergo periodic thermal influence. The mechanical properties of products formed from nickel-based superalloy are slightly superior to those of the original cast material. It is also shown that by wire-feed electron beam technology it is possible to restore damaged products and obtain bimetallic (nickel alloy - bronze) compositions. |
