Feasibility Exploration of Superalloys for AISI 4140 Steel Repairing using Laser Engineered Net Shaping

Due to high strength and ductility, AISI 4141 alloy steel is widely used in many industrial applications, such as gears and blades. When it is composed to harsh working environment, severe mechanical failures may happen. In order to save the high added value of the components, necessary repairing techniques are required to recover their functionality. Laser Engineered Net Shaping (LENS) is an innovative technology for metal parts repairing and rebuilding due to its metallurgical bonding and exhibit heat affected zone (HAZ). Compared to other repairing processes, LENS cannot only reduce the manufacturing time and cost, increase material utilization, but also provide an outstanding as-fabricated mechanical properties. Considering the compatibility and availability of powder materials, the selection of to-be-fabricated materials are important and decisive to the mechanical properties and the quality of the deposits. In this investigation, nickel-based and cobalt based superalloys are deposited onto AISI 4140 steel substrate using laser engineered net shaping (LENS) process to verify the feasibility of these superalloys for repairing of AISI 4140 workpieces. The micro-hardness, tensile strength, fracture and wear resistance are analyzed to testify the resistance of deformation, tension and anti-friction performance of deposited materials.