Achieving High-Quality Formed Hastelloy X Cladding Layers on Heterological 50CrVA Surface by Optimizing Process...

Area of Science:

• Materials Science
• Mechanical Engineering
• Surface Engineering

Background:

• Hastelloy X is a suitable material for repairing 50CrVA landing gear due to its thermal fatigue resistance.
• Differences in properties between Hastelloy X and 50CrVA create challenges in achieving high-quality repairs using directed energy deposition (DED).

Purpose of the Study:

• To investigate the impact of DED process parameters on Hastelloy X claddings on 50CrVA substrates.
• To optimize DED parameters for fabricating high-quality Hastelloy X claddings with desired interfacial microstructure and surface characteristics.
• To evaluate the corrosion-wear performance of the optimized claddings.

Main Methods:

• Utilized thermal-flow coupled simulation models and orthogonal experiments to study DED process parameters (laser power, powder feed rate, scanning speed, overlap rate).
• Analyzed the effects of these parameters on dilution ratio, microscopic morphology, surface flatness, and porosity.
• Evaluated the corrosion and wear resistance of the fabricated claddings.

Main Results:

• Dilution ratio increases with higher laser power or lower powder feed rate, and shows a peak with scanning speed.
• Surface quality is affected by process parameters, with specific ranges leading to ablation marks or ripples.
• Optimal parameters (1600 W, 2.4 g/min, 240 mm/min, 55% overlap) were identified for high-quality claddings.
• Optimized claddings exhibited wear resistance comparable to the 50CrVA substrate and significantly improved corrosion resistance.

Conclusions:

• The developed optimization methodology effectively fabricates high-quality Hastelloy X claddings on 50CrVA.
• The optimized DED process enhances the corrosion resistance of 50CrVA landing gear repairs.
• This research provides a foundation for advanced repair strategies for aircraft components.