Cracking Behavior of the ZhS6K Superalloy during Direct Laser Deposition with Induction Heating

For this work, the behavior of the ZhS6K alloy (Russian grade) in the process of direct laser deposition was investigated. Two samples, a "small" one (40 x 10 x 10 mm3) and "large" one (80 x 16 x 16 mm3), were fabricated with direct laser deposition. In both samples, the typical dual-phase gamma/gamma' microstructure with cuboidal shape of the gamma' precipitates was observed. Both specimens revealed a similar tendency to continuous increasing in hardness from the bottom to the top associated with the refinement of gamma' precipitates. The "small" sample was essentially crack-free, while the "large" one underwent extensive cracking. The possible effects of various factors, including thermal history, size, and shape of the gamma grains, on cracking behavior were discussed.