Optimization of process parameters for direct energy deposition of 15Cr5Ni precipitation hardened stainless steel for aircraft parts repair and maintenance

Abstract

In the aerospace industry, regular maintenance and repair consume maximum cost and time. Direct energy deposition is an effective cutting edge repairing technology used in aircraft parts. This paper projected direct energy deposition as an important cladding technology. And as a cladding material, the acceptability of 15Cr5Ni precipitation-hardened steel is evaluated through single-layer deposition over 304 L stainless steel via direct energy deposition. 15Cr5Ni steel is a high-strength alloy mainly used for jigs, fasteners, and landing gears in the aerospace industry. Optimization of process parameters, that is, laser power, scan speed, and powder feed rate, is performed using response surface methodology through a prediction model along with a validation test. The microstructural investigation of clad cross-section and surface morphology followed by four-dimensional X-ray microscopy reveals an improved clad quality with minimized porosity and defects. A relative error of less than 5% has been found between the prediction model and experimental values, which validate the significance of optimized process parameters toward improving the clad quality for aircraft part repairing purposes.