scholarly journals Development of a Novel High-Temperature Al Alloy for Laser Powder Bed Fusion

Metals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 35
Author(s):  
Filippo Belelli ◽  
Riccardo Casati ◽  
Martina Riccio ◽  
Alessandro Rizzi ◽  
Mevlüt Y. Kayacan ◽  
...  
Keyword(s):  
Tensile Strength ◽  
High Temperature ◽  
Elevated Temperatures ◽  
High Strength ◽  
Al Alloy ◽  
Powder Bed Fusion ◽  
Laser Powder Bed Fusion ◽  
Powder Bed ◽  
Solidification Cracks ◽  
Manufacturing Technologies

The number of available materials for Laser Powder Bed Fusion is still limited due to the poor processability of many standard alloys. In particular, the lack of high-strength aluminium alloys, widely used in aerospace and automotive industries, remains a big issue for the spread of beam-based additive manufacturing technologies. In this study, a novel high-strength aluminium alloy for high temperature applications having good processability was developed. The design of the alloy was done based on the chemical composition of the widely used EN AW 2618. This Al-Cu-Mg-Ni-Fe alloy was modified with Ti and B in order to promote the formation of TiB2 nuclei in the liquid phase able to stimulate heterogeneous nucleation of grains and to decrease the hot cracking susceptibility of the material. The new Al alloy was manufactured by gas atomisation and processed by Laser Powder Bed Fusion. Samples produced with optimised parameters featured relative density of 99.91%, with no solidification cracks within their microstructure. After aging, the material revealed upper yield strength and ultimate tensile strength of 495 MPa and 460 MPa, respectively. In addition, the alloy showed tensile strength higher than wrought EN AW 2618 at elevated temperatures.

High Temperature High Strength Austenitic Steel Fabricated by Laser Powder-Bed Fusion

2021 ◽  
Author(s):  
Sebastien Dryepondt ◽  
Peeyush Nandwana ◽  
Kinga Unocic ◽  
Rangasayee Kannan ◽  
Patxi Fernandez Zelaia ◽  
...  
Keyword(s):  
High Temperature ◽  
Austenitic Steel ◽  
High Strength ◽  
Powder Bed Fusion ◽  
Laser Powder Bed Fusion ◽  
Powder Bed

High strength Al alloy development for laser powder bed fusion

2021 ◽  
pp. 2141001
Author(s):  
Jin’e Sun ◽  
Baicheng Zhang ◽  
Xuanhui Qu
Keyword(s):  
High Strength ◽  
Nucleation Site ◽  
Al Alloys ◽  
Hot Tearing ◽  
Al Alloy ◽  
Powder Bed Fusion ◽  
Laser Powder Bed Fusion ◽  
Alloy Development ◽  
Powder Bed ◽  
Columnar Grain

High strength Al alloy development is the key technique to additive manufacturing (AM) applied on lightweight of aerospace, automotive and military industry. Unlike the conventional wrought Al–Si eutectic alloys available for AM process, the strength of new developed Al alloy can be improved by in situ or additional nano-precipitated phase. This paper presents an overview of high strength Al alloys development including metallic additives, such as Zr, Sc, Mn, Cu, etc., and nanoparticle additives, such as ceramics (TiB2, TiC, LaB6 and TiN) as well as carbon nanotubes (CNTs). The addition of Zr and Sc elements significantly prevents hot tearing and enhances the strength of laser processed Al alloys because the nanoscale Al3Zr, Al3Sc and Al3 (Sc, Zr) precipitated phases generate, facilitate the heterogeneous nucleation of Al matrix and refine the microstructure. Moreover, the addition of Mn and Cu elements provides an increment in the toughness and strength of laser processed Al alloys through the superimposed effect of multi-element solid solution reinforcement and precipitation strengthening role of some Al2CuMg and Al6Mn. The growth process of Al alloy can be interrupted by the addition of nanoceramics particles as additional nucleation site which leads the columnar grain transforms to the equiaxed grain. Furthermore, the mechanism of mutual solubility of LaB6, TiB2, TiC and TiN in Al alloys is systematically studied. Finally, an assessment of the state in laser processed high strength Al alloys and the research demands for the expansion of laser powder bed fusion of Al metallic components are provided.

scholarly journals Tensile Properties of 21-6-9 Austenitic Stainless Steel Built Using Laser Powder-Bed Fusion

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4280
Author(s):  
Magnus Neikter ◽  
Emil Edin ◽  
Sebastian Proper ◽  
Phavan Bhaskar ◽  
Gopi Krishna Nekkalapudi ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Tensile Properties ◽  
Elevated Temperatures ◽  
High Strength ◽  
Industrial Applications ◽  
Powder Bed Fusion ◽  
Laser Powder Bed Fusion ◽  
Anisotropic Behavior ◽  
Powder Bed

Alloy 21-6-9 is an austenitic stainless steel with high strength, thermal stability at high temperatures, and retained toughness at cryogenic temperatures. This type of steel has been used for aerospace applications for decades, using traditional manufacturing processes. However, limited research has been conducted on this alloy manufactured using laser powder-bed fusion (LPBF). Therefore, in this work, a design of experiment (DOE) was performed to obtain optimized process parameters with regard to low porosity. Once the optimized parameters were established, horizontal and vertical blanks were built to investigate the mechanical properties and potential anisotropic behavior. As this alloy is exposed to elevated temperatures in industrial applications, the effect of elevated temperatures (room temperature and 750 °C) on the tensile properties was investigated. In this work, it was shown that alloy 21-6-9 could be built successfully using LPBF, with good properties and a density of 99.7%, having an ultimate tensile strength of 825 MPa, with an elongation of 41%, and without any significant anisotropic behavior.

scholarly journals Effect of Build Orientation on the Microstructure, Mechanical and Corrosion Properties of a Biodegradable High Manganese Steel Processed by Laser Powder Bed Fusion

Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 944
Author(s):  
Martin Otto ◽  
Stefan Pilz ◽  
Annett Gebert ◽  
Uta Kühn ◽  
Julia Hufenbach
Keyword(s):  
Electron Backscatter Diffraction ◽  
Longitudinal Axis ◽  
Manganese Steel ◽  
Compressive Yield Strength ◽  
Powder Bed Fusion ◽  
Compression Tests ◽  
Laser Powder Bed Fusion ◽  
Corrosion Properties ◽  
Powder Bed ◽  
Manufacturing Technologies

In the last decade, additive manufacturing technologies like laser powder bed fusion (LPBF) have emerged strongly. However, the process characteristics involving layer-wise build-up of the part and the occurring high, directional thermal gradient result in significant changes of the microstructure and the related properties compared to traditionally fabricated materials. This study presents the influence of the build direction (BD) on the microstructure and resulting properties of a novel austenitic Fe‑30Mn‑1C‑0.02S alloy processed via LPBF. The fabricated samples display a {011} texture in BD which was detected by electron backscatter diffraction. Furthermore, isolated binding defects could be observed between the layers. Quasi-static tensile and compression tests displayed that the yield, ultimate tensile as well as the compressive yield strength are significantly higher for samples which were built with their longitudinal axis perpendicular to BD compared to their parallel counterparts. This was predominantly ascribed to the less severe effects of the sharp-edged binding defects loaded perpendicular to BD. Additionally, a change of the Young’s modulus in dependence of BD could be demonstrated, which is explained by the respective texture. Potentiodynamic polarization tests conducted in a simulated body fluid revealed only slight differences of the corrosion properties in dependence of the build design.

High strength WE43 microlattice structures additively manufactured by laser powder bed fusion

Materialia ◽  
2021 ◽  
Vol 16 ◽  
pp. 101067
Author(s):  
Holden Hyer ◽  
Le Zhou ◽  
Qingyang Liu ◽  
Dazhong Wu ◽  
Shutao Song ◽  
...  
Keyword(s):  
High Strength ◽  
Powder Bed Fusion ◽  
Laser Powder Bed Fusion ◽  
Powder Bed

scholarly journals Effects of Positioning Conditions on Material Properties In Powder bed Fusion Additive Manufacturing

2021 ◽  
Author(s):  
Mevlüt Yunus Kayacan ◽  
Nihat Yılmaz
Keyword(s):  
Additive Manufacturing ◽  
Material Properties ◽  
Layer By Layer ◽  
Powder Bed Fusion ◽  
Laser Powder Bed Fusion ◽  
Cooling Rates ◽  
Powder Bed ◽  
Manufacturing Technologies ◽  
Average Size ◽  
Hardness Values

Abstract Among additive manufacturing technologies, Laser Powder Bed Fusion (L-PBF) is considered the most widespread layer-by-layer process. Although the L-PBF, which is also called as SLM method, has many advantages, several challenging problems must be overcome, including part positioning issues. In this study, the effect of part positioning on the microstructure of the part in the L-PBF method was investigated. Five Ti6Al4V samples were printed in different positions on the building platform and investigated with the aid of temperature, porosity, microstructure and hardness evaluations. In this study, martensitic needles were detected within the microstructure of Ti6Al4V samples. Furthermore, some twins were noticed on primary martensitic lines and the agglomeration of β precipitates was observed in vanadium rich areas. The positioning conditions of samples were revealed to have a strong effect on temperature gradients and on the average size of martensitic lines. Besides, different hardness values were attained depending on sample positioning conditions. As a major result, cooling rates were found related to positions of samples and the location of point on the samples. Higher cooling rates and repetitive cooling cycles resulted in microstructures becoming finer and harder.

Dislocation-induced ultra-high strength in a novel steel fabricated using laser powder-bed-fusion

2021 ◽  
pp. 142502
Author(s):  
Wei Li ◽  
Jikang Li ◽  
Xianyin Duan ◽  
Chuanyue He ◽  
Qingsong Wei ◽  
...  
Keyword(s):  
High Strength ◽  
Powder Bed Fusion ◽  
Laser Powder Bed Fusion ◽  
Powder Bed
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