Investigation of cracking causes during multi-pass laser cladding of heat-resistant single crystal nickel alloy
Rudolf Korsmik, Olga Klimova-Korsmik, Ekaterina Valdaytseva, Ilya Udin
Abstract
ZhS32 is Ni-based single crystal superalloy has been successfully used in aero and industrial gas turbine applications. Vibrations, shocks, abrasive wear, high temperatures applied to gas turbine blades lead to its damage. Taking into account the complexity of production and the high cost of new blades, after the exploitation of their resource, the blades must be restored. Laser cladding, as one type of DED process, is applicable to repairing operation for machines and mechanisms are subjected to the impact of aggressive environment and surface wear. superalloys with a high γ’-volume fraction are strongly susceptible to crack formation, e.g., strain age or liquidation cracking. The influence of main cladding parameters on the potential defects of deposited metal is considered. Based on the obtained dependencies, the criteria allow obtaining a defect-free clad with controlled structure are determined. As result of investigation, a technological recommendations for restoration laser powder cladding of turbine blades from heat-resistant nickel alloys is developed.