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Multiscale Investigation of Inconel 718 Microstructure and Mechanical Properties by SLM

2023-07-26 14:59:03  Knowledge

inconel 718 is a nickel-chromium-molybdenum alloy that contains niobium and titanium to enhance its oxidation resistance, pitting, and crevice corrosion resistance, weldability, and strength. It is used from cryogenic temperatures to high-temperature applications requiring exceptional resistance and strength. Its properties are useful in a number of industries including aerospace, oil and gas, chemical processing, nuclear reactors, and more.

With a yield strength of up to 90 ksi, it is no surprise that inconel 718 is a popular choice for aerospace and engineering components. Its ability to withstand extreme temperatures and environments makes it ideal for jet engines, oil & gas pipelines, and nuclear power plants.

In addition to its strength, inconel 718 has excellent formability and ductility and can be easily welded. It also resists stress corrosion cracking and oxidation. However, its high tensile strength and creep resistance can be challenging to machine.

Traditional machining of inconel 718 can cause the material to generate high cutting temperatures, which can damage tooling and promote built-up edge formation. This can ultimately compromise the mechanical integrity and machinability of the component.

Additive manufacturing has shown to be an effective method for reducing these problems and can produce high-quality components with the same mechanical properties as wrought parts. This article presents a multiscale investigation of the microstructures and mechanical properties of inconel 718 parts produced by selective laser melting (SLM). The as-built SLM parts were found to have unique multi-scale microstructure features, including columnar cube-textured grains, cellular dendritic and annealing twins due to segregation, and micrometer-sized precipitates. Heat treatment was found to be a highly effective method for improving and homogenizing the SLM-created microstructure and enhancing mechanical performance.