A Short Review on the Microstructure, Transformation Behavior and Functional Properties of NiTi Shape Memory Alloys Fabricated by Selective Laser Melting

Wang, Xiebin; Kustov, S.; Humbeeck, Jan Van

doi:10.3390/ma11091683

Cited by 104 publications

(45 citation statements)

References 105 publications

(211 reference statements)

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“…The excess of energy is related to the normal bell formed Gaussian distribution. This leads to the formation of a solid solution between the material of the substrate and has effects on the chemical and microstructural homogeneity of the subsequent layers of the object [74]. This effect is related to the character of the energy distribution in the laser spot, which is close to the Gaussian profile and can be approximated by a Gaussian function [18,75].…”

Section: Classification Of the Main Slm Parameters And The Way Of Lasmentioning

confidence: 99%

Power Density Distribution for Laser Additive Manufacturing (SLM): Potential, Fundamentals and Advanced Applications

et al. 2018

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Problems with the laser additive manufacturing of metal parts related to its low efficiency are known to hamper its development and application. The method of selective laser melting of metallic powders can be improved by the installation of an additional laser beam modulator. This allows one to control the power density distribution optically in the laser beam, which can influence the character of heat and mass transfer in a molten pool during processing. The modulator contributes alternative modes of laser beam: Gaussian, flat top (top hat), and donut (bagel). The study of its influence includes a mathematical description and theoretical characterization of the modes, high-speed video monitoring and optical diagnostics, characterization of processing and the physical phenomena of selective laser melting, geometric characterization of single tracks, optical microscopy, and a discussion of the obtained dependences of the main selective laser melting (SLM) parameters and the field of its optimization. The single tracks were produced using the advanced technique of porosity lowering. The parameters of the obtained samples are presented in the form of 3D graphs. The further outlook and advanced applications are discussed.

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Section: Classification Of the Main Slm Parameters And The Way Of Lasmentioning

confidence: 99%

Power Density Distribution for Laser Additive Manufacturing (SLM): Potential, Fundamentals and Advanced Applications

et al. 2018

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“…LPBF is a cyclic super rapid heating and cooling process. For example, the cooling rate of the LPBF process can reach 10 6 K/s [38,39], in which the microstructure is in a non-equilibrium state and the grain growth and segregation of alloy elements are restrained accordingly [40][41][42][43][44]. Because of the large temperature gradient and complex heat transfer caused by laser beam cyclic processing, the microstructure and properties of the alloy tend to be anisotropic, and new metastable or even amorphous phases may be generated [45][46][47][48].…”

Section: Introductionmentioning

confidence: 99%

A Review on Laser Powder Bed Fusion of Inconel 625 Nickel-Based Alloy

et al. 2019

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The Inconel 625 (IN625) superalloy has a high strength, excellent fatigue, and creep resistance under high-temperature and high-pressure conditions, and is one of the critical materials used for manufacturing high-temperature bearing parts of aeroengines. However, the poor workability of IN625 alloy prevents IN625 superalloy to be used in wider applications, especially in applications requiring high geometrical complexity. Laser powder bed fusion (LPBF) is a powerful additive manufacturing process which can produce metal parts with high geometrical complexity and freedom. This paper reviews the studies that have been done on LPBF of IN625 focusing on the microstructure, mechanical properties, the development of residual stresses, and the mechanism of defect formation. Mechanical properties such as microhardness, tensile properties, and fatigue properties reported by different researchers are systematically summarized and analyzed. Finally, the remaining issues and suggestions on future research on LPBF of IN625 alloy parts are put forward.

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“…However, the additive manufacturing of Ni-Ti represents only a small fraction of the medical applications produced by metal-based additive manufacturing, and only a handful of studies on the additive manufacturing of Ni-Ti consider its stimuli-responsive properties, such as the very low stiffness (very low E-modulus), and its functional properties, such as superelasticity and the shape memory effect. However, a fair amount of research on the laser additive manufacturing (LAM) of Ni-Ti shape memory alloys has been conducted [23,115,[171][172][173][174]. Therefore, we summarize here the most important observations of Ni-Ti deposited using L-PBF, as previously discussed by [173] and briefly overviewed in Table 2. • Although Ni-Ti can be processed at a high density crack-free, the mechanical and functional properties of the processed material are on average inferior compared to the wrought material.…”

Section: Micro L-pbfmentioning

confidence: 99%