Adjusted Process Conditions in Laser Powder Bed Fusion to Obtain a Single-Crystal-Like Microstructure in IN718

2021 ◽  
Vol 1161 ◽  
pp. 39-46
Author(s):  
Alexander F. Frey ◽  
Christoph Seyfert ◽  
Peter J. Holfelder
Keyword(s):  
Mechanical Properties ◽  
Single Crystal ◽  
Base Alloy ◽  
Spot Size ◽  
Process Conditions ◽  
Powder Bed Fusion ◽  
Laser Powder Bed Fusion ◽  
Powder Bed ◽  
Anisotropic Mechanical Properties ◽  
Nickel Base

The nickel base alloy IN718 was manufactured by Laser Powder Bed Fusion (LPBF) using a laser spot size of 1024 μm and a laser power of 1.3 kW at a layer thickness of 160μm. The resulting porosity, microstructure and mechanical properties are presented. Very coarse and in build direction elongated grains are stacked to form a polycrystalline material with sharp single-crystal-like texture. The appearance of ∑5 grain boundaries between coincidence side lattices is recognized. Tensile testing shows highly anisotropic mechanical properties according to the revealed texture. Increasing the hatch distance reduces the severity of the texture.

Effects of Powder Attributes and Laser Powder Bed Fusion (L-PBF) Process Conditions on the Densification and Mechanical Properties of 17-4 PH Stainless Steel

JOM ◽  
2016 ◽  
Vol 68 (3) ◽  
pp. 860-868 ◽  
Author(s):  
Harish Irrinki ◽  
Michael Dexter ◽  
Brenton Barmore ◽  
Ravi Enneti ◽  
Somayeh Pasebani ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Process Conditions ◽  
Powder Bed Fusion ◽  
Laser Powder Bed Fusion ◽  
Powder Bed

scholarly journals Study on Laser Powder Bed Fusion of Nickel-base Alloy: Scanning Strategy, Properties and Compression Properties

2020 ◽  
Author(s):  
Bo Qian ◽  
Hongri Fan ◽  
Tengfei Li ◽  
Jianrui Zhang ◽  
Jiangtao Xi ◽  
...  
Keyword(s):  
Surface Structure ◽  
Base Alloy ◽  
Powder Bed Fusion ◽  
Nickel Base Alloy ◽  
Laser Powder Bed Fusion ◽  
Scanning Strategy ◽  
Powder Bed ◽  
Compression Performance ◽  
Nickel Base ◽  
Scanning Strategies

Abstract Aiming at laser powder bed fusion of GH3536 nickel base alloy, the effects of different scanning strategies on microstructure, porosity and mechanical properties were explored. In the aspect of microstructure and micro hardness of the sample, three scanning strategies had little difference; in the aspect of macro mechanical properties of the sample, the slope subarea scanning was better than the helix and island scanning. On this basis, the slope subarea scanning was selected as the optimal scanning strategy to form the G-surface structure, and the compression performance of G-surface was studied. The results showed that: (1) the compression performance of G-surface structure was smaller than that of solid structure; while G-surface structure had a smooth compression curve, which indicated the good energy absorption characteristics; (2) with the increase of wall thickness, the mechanical performance of G-surface structure was also enhanced, while the energy absorption capacity was constantly reduced; (3) with the same wall thickness, the compression performance of sample in building direction (BD) is higher than that in horizontal direction (HD).

scholarly journals Determination of Anisotropic Mechanical Properties for Materials Processed by Laser Powder Bed Fusion

2018 ◽  
Vol 2018 ◽  
pp. 1-20 ◽  
Author(s):  
Even W. Hovig ◽  
Amin S. Azar ◽  
Frode Grytten ◽  
Knut Sørby ◽  
Erik Andreassen
Keyword(s):  
Mechanical Properties ◽  
Transversely Isotropic ◽  
Tensile Tests ◽  
Image Correlation ◽  
Powder Bed Fusion ◽  
Laser Powder Bed Fusion ◽  
Inconel 718 Alloy ◽  
Powder Bed ◽  
Anisotropic Mechanical Properties ◽  
Anisotropic Elastic

Improving the success rate in additive manufacturing and designing highly optimized structures require proper understanding of material behaviour. This study proposes a novel experimental method by which anisotropic mechanical properties of additively manufactured materials can be assessed. The procedure is based on tensile testing of flat specimens, manufactured by laser powder bed fusion (LPBF) at different orientations relative to the build plate. In this study, the procedure was applied to the Inconel 718 alloy. Three identical specimen sets were built, each of which received complementary postprocessing treatments. The tensile tests were carried out on specimens with as-built surface finish. Digital image correlation was used to record the strain field evolution on two perpendicular surfaces of the tensile specimens under loading. An optimization algorithm is also proposed for determining the anisotropic elastic constants using only a few tensile test results. It was observed that both build orientation and postprocessing have strong influence on the anisotropic mechanical properties of the material. The effect of microstructure was also investigated and characterised. Consequently, three transversely isotropic compliance matrices were constructed, representing the effect of the different processing conditions.

scholarly journals Effect of Process and Post-Process Conditions on the Mechanical Properties of an A357 Alloy Produced via Laser Powder Bed Fusion

Metals ◽  
2017 ◽  
Vol 7 (2) ◽  
pp. 68 ◽  
Author(s):  
Alberta Aversa ◽  
Massimo Lorusso ◽  
Francesco Trevisan ◽  
Elisa Ambrosio ◽  
Flaviana Calignano ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Process Conditions ◽  
Powder Bed Fusion ◽  
Laser Powder Bed Fusion ◽  
A357 Alloy ◽  
Powder Bed ◽  
Post Process

scholarly journals In Situ Alloying of a Modified Inconel 625 via Laser Powder Bed Fusion: Microstructure and Mechanical Properties

Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 988
Author(s):  
Giulio Marchese ◽  
Margherita Beretta ◽  
Alberta Aversa ◽  
Sara Biamino
Keyword(s):  
Mechanical Properties ◽  
Base Alloy ◽  
Heat Treatments ◽  
Inconel 625 ◽  
Powder Bed Fusion ◽  
Laser Powder Bed Fusion ◽  
Powder Bed ◽  
Melt Pool ◽  
Composition Modification

This study investigates the in situ alloying of a Ni-based superalloy processed by means of laser powder bed fusion (LPBF). For this purpose, Inconel 625 powder is mixed with 1 wt.% of Ti6Al4V powder. The modified alloy is characterized by densification levels similar to the base alloy, with relative density superior to 99.8%. The material exhibits Ti-rich segregations along the melt pool contours. Moreover, Ti tends to be entrapped in the interdendritic areas during solidification in the as-built state. After heat treatments, the modified Inconel 625 version presents greater hardness and tensile strengths than the base alloy in the same heat-treated conditions. For the solution annealed state, this is mainly attributed to the elimination of the segregations into the interdendritic structures, thus triggering solute strengthening. Finally, for the aged state, the further increment of mechanical properties can be attributed to a more intense formation of phases than the base alloy, due to elevated precipitation strengthening ability under heat treatments. It is interesting to note how slight chemical composition modification can directly develop new alloys by the LPBF process.

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