Journal ArticleDOI
A Study on Laser Beam Welding (LBW) Technique: Effect of Heat Input on the Microstructural Evolution of Superalloy Inconel 718
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The effect of heat input from laser beam welding (LBW) on the microstructural evolution of superalloy Inconel 718 was investigated in this article, where LBW was carried out on 1.6-mm-thick sheets with an average grain size of 13 μm (ASTM # 9.5).Abstract:
The effect of heat input from laser beam welding (LBW) on the microstructural evolution of superalloy Inconel 718 was investigated. LBW was carried out on 1.6-mm-thick sheets with an average grain size of 13 μm (ASTM # 9.5), and four different heat inputs in the range of 74.5 mm−1 to 126.6 J mm−1 were used. Full penetration was achieved in all weld experiments. Microstructures of the welds were evaluated using an optical microscope and a field emission scanning electron microscope. Increasing the heat input changed the resulting weld shape from a wine glass shape to a stemless glass shape with wider surface bead widths, and the measured average dendrite arm spacing was increased from 1.06 μm to 2.30 μm, indicating the corresponding solidification rate in the range of 1.75 × 105 K s−1 (°C s−1) to 3.5 × 106 K s−1 (°C s−1). The welds also were free from microfissuring even at the lowest heat input trials. The Nb concentration of Laves phase for the current LBW samples was ≈20.0 wt pct. The coefficients of partition and distribution for Nb were determined to be approximately 3.40 and 0.50, respectively.read more
Citations
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Effect of energy input on microstructural evolution of direct laser fabricated IN718 alloy
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Effect of base metal and welding speed on fusion zone microstructure and HAZ hot-cracking of electron-beam welded Inconel 718
TL;DR: In this paper, the authors investigated the influence of welding speed and base metal grain size on the microstructures of EBW Inconel 718 and found that the weld shape transforms from a stemless wine glass shape to a nail head shape with the increase of the grain size of base metal.
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Online monitoring of thermo-cycles and its correlation with microstructure in laser cladding of nickel based super alloy
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References
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Journal ArticleDOI
Effect of laser welding parameters on the heat input and weld-bead profile
TL;DR: In this paper, the effect of laser power (1.2-1.43kW), welding speed (30-70 cm/min) and focal point position (−2.5 to 0mm) on the heat input and the weld-bead geometry (i.e. penetration, welded zone width, and heat affected zone width (W HAZ )) was investigated using response surface methodology (RSM).
Journal ArticleDOI
INCONEL 718: A solidification diagram
TL;DR: In this paper, the authors used an integrated analytical approach to generate a constitution diagram for INCONEL 718* in the temperature range associated with solidification, where the important features of the diagram are an austenite (γ)/Laves phase eutectic which occurs at ≈19.1 wt pct Nb and a Laves phase which contains ≈22.4 wt nb. The distribution coefficient for Nb was found to be ≈0.5.
Journal ArticleDOI
Progress in joining of advanced materials
Gürel Çam,Mustafa Koçak +1 more
TL;DR: In this article, diffusion bonding and laser welding are considered for joining a wide range of materials of interest in the aerospace industry, as well as in many other industrial applications, and offer remarkable advantages over conventional fusion welding processes.
Journal ArticleDOI
The formation and control of Laves phase in superalloy 718 welds
Ch Radhakrishna,K Prasad Rao +1 more
TL;DR: In this article, the microstructural characteristics and segregational features in alloy 718 welds, with low heat inputs proving beneficial, were found to form in the interdendritic regions of the weld metals as a result of segregation.
Journal ArticleDOI
Microstructure and tensile properties of Inconel 718 pulsed Nd-YAG laser welds
TL;DR: Pulsed Nd-YAG laser welding characteristics of Inconel 718 sheet material (2.mm thick) were investigated in this article, where Weld microstructures and room temperature tensile properties were evaluated.
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