Machining-induced surface integrity of Inconel 718 alloy fabricated by powder bed fusion additive manufacturing under various laser processing parameters

2021 ◽  
pp. 1-23
Author(s):  
Emre Taşcıoğlu ◽  
Yusuf Kaynak ◽  
Safian Sharif ◽  
Fatih Pıtır ◽  
Mohd Azlan Suhaimi
Keyword(s):  
Additive Manufacturing ◽  
Surface Integrity ◽  
Inconel 718 ◽  
Laser Processing ◽  
Processing Parameters ◽  
Powder Bed Fusion ◽  
Inconel 718 Alloy ◽  
Powder Bed

scholarly journals Studies of Post-Fabrication Heat Treatment of L-PBF-Inconel 718: Effects of Hold Time on Microstructure, Annealing Twins, and Hardness

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 266
Author(s):  
Wakshum M. Tucho ◽  
Vidar Hansen
Keyword(s):  
Heat Treatment ◽  
Solid Solution ◽  
Additive Manufacturing ◽  
Inconel 718 ◽  
Solution Heat Treatment ◽  
Hold Time ◽  
Powder Bed Fusion ◽  
Powder Bed ◽  
Annealing Twins ◽  
Complete Recrystallization

The widely adopted temperature for solid solution heat treatment (ST) for the conventionally fabricated Inconel 718 is 1100 °C for a hold time of 1 h or less. This ST scheme is, however, not enough to dissolve Laves and annihilate dislocations completely in samples fabricated with Laser metal powder bed fusion (L-PBF) additive manufacturing (AM)-Inconel 718. Despite this, the highest hardness obtained after aging for ST temperatures (970–1250 °C) is at 1100 °C/1 as we have ascertained in our previous studies. The unreleased residual stresses in the retained lattice defects potentially affect other properties of the material. Hence, this work aims to investigate if a longer hold time of ST at 1100 °C will lead to complete recrystallization while maintaining the hardness after aging or not. For this study, L-PBF-Inconel 718 samples were ST at 1100 °C at various hold times (1, 3, 6, 9, 16, or 24 h) and aged to study the effects on microstructure and hardness. In addition, a sample was directly aged to study the effects of bypassing ST. The samples (ST and aged) gain hardness by 43–49%. The high density of annealing twins evolved during 3 h of ST and only slightly varies for longer ST.

Laser Welding of Laser Powder Bed Fusion Manufactured Inconel 718: Microstructure and Mechanical Properties

2021 ◽  
Vol 883 ◽  
pp. 234-241
Author(s):  
Timo Rautio ◽  
Jarmo Mäkikangas ◽  
Jani Kumpula ◽  
Antti Järvenpää ◽  
Atef Hamada
Keyword(s):  
Mechanical Properties ◽  
Inconel 718 ◽  
Tensile Tests ◽  
Optical Microscope ◽  
Powder Bed Fusion ◽  
Laser Powder Bed Fusion ◽  
Inconel 718 Alloy ◽  
Powder Bed ◽  
Back Scattering ◽  
Solidification Crack

This paper focuses on the laser weldability of additively manufactured (AM) Inconel 718. The experiments of this research were conducted on different series of AM Inconel 718 alloy, i.e. as­-built, heat­ treated (HT), and HT after welding, and comprehensively characterized using optical microscope and electron back scattering diffraction (EBSD). The weld morphology and microstruc­tural evolution of the fusion zone were recorded. The mechanical properties of the welded AM Inconel 718 were evaluated by tensile tests and hardness measurements. It was found that solidification crack and micropore defects are induced in the as­built AM Inconel 718. However, defect­free weld was promoted in the HT alloy. The changes in hardness profiles and tensile strength under the experimen­tal parameters were further reported. Homogenous hardness of 500 HV across the weld was obtained when HT was applied after the LW.

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