Suitability of Laser Engineered Net Shaping Technology for Inconel 625 Based Parts Repair Process

Abstract

In this paper, the Inconel 625 laser clads characterized by microstructural homogeneity due to the application of the Laser Engineered Net Shaping (LENS, Optomec, Albuquerque, NM, USA) technology were studied in detail. The optimized LENS process parameters (laser power of 550 W, powder flow rate of 19.9 g/min, and heating of the substrate to 300 °C) enabled to deposit defect-free laser cladding. Additionally, the laser clad was applied in at least three layers on the repairing place. The deposited laser clads were characterized by slightly higher mechanical properties in comparison to the Inconel 625 substrate material. Microscopic observations and X-ray Tomography (XRT, Nikon Corporation, Tokyo, Japan) confirmed, that the substrate and cladding interface zone exhibited a defect-free structure. Mechanical properties and flexural strength of the laser cladding were examined using microhardness and three-point bending tests. It was concluded, that the LENS technology could be successfully applied for the repair since a similar strain distribution was found after Digital Image Correlation measurements during three-point bending tests.

Fabrication of MnCuNiFe–CuAlNiFeMn Gradient Alloy by Laser Engineering Net Shaping System

“…Compared with existing studies, the M2052–NAB alloy interface possesses a good metallurgical bond [ 32 ], and the corrosion resistance in the 3.5% NaCl solution is higher than that of the as-cast and SLM deposited alloys.…”

“…The self-corrosion current density was 7.24 × 10 −6 A/cm 2 , which is lower than that of the as-cast alloy and SLM deposited alloys; The deposited alloy had tiny pores and irregular pore defects caused by molten pool collapse, which affected the material properties. The printing parameters of the alloy have not yet been analyzed and optimized, so there is still potential for improvement in the performance of the gradient alloy; Compared with existing studies, the M2052–NAB alloy interface possesses a good metallurgical bond [ 32 ], and the corrosion resistance in the 3.5% NaCl solution is higher than that of the as-cast and SLM deposited alloys. …”

“…Laser engineering net shaping (LENS) is a type of AM in which parts are processed layer by layer through coaxial powder feeding. The powder ratio can be freely adjusted during processing, which has obvious advantages in the preparation of vertical gradient materials [ 31 , 32 , 33 ]. In terms of materials, we chose M2052 alloy, widely used in the field of vibration and noise reduction, and developed M2052–NAB gradient alloy based on NAB alloy, the mainstream material in the field of marine propellers [ 34 , 35 , 36 ].…”