Effect of the Laser Cladding Parameters on the Crack Formation and Microstructure during Nickel Superalloy Gas Turbine Engines Repair

Abstract

Cracking of nickel superalloys with a high content of γ’-phase remains an unresolved problem, including in technologies for repairing gas turbine engines blades. Laser cladding is a method of material deposition used to repair parts exposed to aggressive environment and surface wear. Cladding parameters have a high influence on cracking susceptibility nickel superalloys. Alloy ZhS32 has a high propensity for hot cracking when exposed to laser radiation. In this work, the study of the structural and phase features of ZhS32 alloy was carried out. A high tendency to form segregation of refractory elements and carbides in the intergranular areas was found. The features of the structure and phase composition of the material for different cladding parameters were studied. The main contribution of technological parameters to the formation of cracks is shown.

Crack Formation Mechanisms and Control Methods of Laser Cladding Coatings: A Review

“…Consequently, the grain growth time is prolonged, resulting in coarser grains, as well as the formation of pores or impurities. The hot cracks in HSLA powder samples (the laser power is 2900 W and the scan speed is 10 mm/s) [25]; (b) the cold cracks in Ni-Cu alloy sample (the laser power is 5000 W and the scan speed is 30 mm/s) [35]; (c) cladding layer crack in ZhS32 alloy (the laser power is 600 W and the scan speed is 9 mm/s) [36]; (d) interface substrate crack in nickel-based K477A (the laser power is 576 W and the scan speed is 4 mm/s) [37]; (e) overlap zone crack in Ni60 (the laser power is 3200 W and the scan speed is 416.7 mm/s) [38].…”

“…Different types of crack morphology. (a)The hot cracks in HSLA powder samples (the laser power is 2900 W and the scan speed is 10 mm/s)[25]; (b) the cold cracks in Ni-Cu alloy sample (the laser power is 5000 W and the scan speed is 30 mm/s)[35]; (c) cladding layer crack in ZhS32 alloy (the laser power is 600 W and the scan speed is 9 mm/s)[36]; (d) interface substrate crack in nickel-based K477A (the laser power is 576 W and the scan speed is 4 mm/s)[37]; (e) overlap zone crack in Ni60 (the laser power is 3200 W and the scan speed is 416.7 mm/s)[38].…”