Microstructure Morphology and Performance Characteristics of a Nickel-based Alloy Part Fabricated by Laser Metal Deposition Shaping
K. Zhang, X-F. Shang and W-J. Liu
Laser metal deposition shaping (LMDS) is a new rapid manufacturing technology, which involves computer aided design, laser processing, material science and numerical control machining. This advanced technology can build fully-dense metal components directly from computer aided design (CAD) files without any mould or tool. In order to master the microstructure morphology and property features of as-formed metal parts, a kind of nickel-based alloy powder was selected to perform this experiment. Typically, the thin-wall part was manufactured with single-pass and multi-layer depositing process. Then, the metallographic samples and tensile specimens were cut out from the thin-wall part for analyzing material characteristics. The results show that there are different grain categories distributing in certain vertical position of thin-wall part, which depends on both temperature gradient and solidification rate at the solid/liquid interface. Furthermore, influenced by the microstructure distributing features of as-deposited component, the mechanical properties represent as anisotropy.
Keywords: Laser metal deposition shaping (LMDS), nickel-based alloy, microstructure morphology, mechanical property characteristics, thin-wall part, grain categories