Effects of laser scanning strategies on selective laser melting of pure tungsten

The laser scanning strategy has an important influence on the surface quality, residual stress, and deformation of the molten metal (deformation behavior). A divisional scanning strategy is an effective means used to reduce the internal stress of the selective laser melting (SLM) metal part. In order to understand and optimize the divisional scanning strategy, three divisional scanning strategies and an S-shaped orthogonal scanning strategy are used to produce 316L steel parts in this study. The influence of scanning strategy on the produced parts is verified from the aspects of densification, residual stress distribution and deformation. Experiments show that the 316L steel alloy parts adopted spiral divisional scanning strategy can not only obtain the densification of 99.37%, but they also effectively improve the distribution of residual stress and control the deformation degree of the produced parts. Among them, the spiral divisional scanning sample has the smallest residual stress in plane direction, and its σx and σy stress are controlled within 204 MPa and 103 MPa. The above results show that the spiral divisional scanning is the most conducive strategy to obtain higher residual stress performance of SLM 316L steel parts.

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Influence of Particle Size on Laser Absorption and Scanning Track Formation Mechanisms of Pure Tungsten Powder During Selective Laser Melting

Engineering ◽

10.1016/j.eng.2019.07.003 ◽

2019 ◽

Vol 5 (4) ◽

pp. 736-745 ◽

Cited By ~ 10

Author(s):

Jiayao Zhang ◽

Dongdong Gu ◽

Ying Yang ◽

Hongmei Zhang ◽

Hongyu Chen ◽

...

Keyword(s):

Particle Size ◽

Selective Laser Melting ◽

Tungsten Powder ◽

Formation Mechanisms ◽

Pure Tungsten ◽

Laser Melting ◽

Laser Absorption ◽

Track Formation

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Fabrication of Mesh Patterns Using a Selective Laser-Melting Process

Applied Sciences ◽

10.3390/app9091922 ◽

2019 ◽

Vol 9 (9) ◽

pp. 1922 ◽

Cited By ~ 3

Author(s):

Tae Woo Hwang ◽

Young Yun Woo ◽

Sang Wook Han ◽

Young Hoon Moon

Keyword(s):

Selective Laser Melting ◽

Laser Scanning ◽

Dimensional Accuracy ◽

Base Plate ◽

Steel Powder ◽

Melting Process ◽

304 Stainless Steel ◽

Process Conditions ◽

Laser Melting ◽

Metal Mesh

The selective laser-melting (SLM) process can be applied to the additive building of complex metal parts using melting metal powder with laser scanning. A metal mesh is a common type of metal screen consisting of parallel rows and intersecting columns. It is widely used in the agricultural, industrial, transportation, and machine protection sectors. This study investigated the fabrication of parts containing a mesh pattern from the SLM of AISI 304 stainless steel powder. The formation of a mesh pattern has a strong potential to increase the functionality and cost-effectiveness of the SLM process. To fabricate a single-layered thin mesh pattern, laser layering has been conducted on a copper base plate. The high thermal conductivity of copper allows heat to pass through it quickly, and prevents the adhesion of a thin laser-melted layer. The effects of the process conditions such as the laser scan speed and scanning path on the size and dimensional accuracy of the fabricated mesh patterns were characterized. As the analysis results indicate, a part with a mesh pattern was successfully obtained, and the application of the proposed method was shown to be feasible with a high degree of reliability.

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Liquation and Crystallization Cracks in Aluminum Alloy AA2024 during Selective Laser Melting

Defect and Diffusion Forum ◽

10.4028/www.scientific.net/ddf.410.203 ◽

2021 ◽

Vol 410 ◽

pp. 203-208

Author(s):

I.S. Loginova ◽

N.A. Popov ◽

A.N. Solonin

Keyword(s):

Aluminum Alloy ◽

Selective Laser Melting ◽

Laser Scanning ◽

Scanning Speed ◽

Melting Zone ◽

Alloying Elements ◽

Laser Melting ◽

Laser Scanning Speed ◽

Positive Effect

In this work we studied the microstructure and microhardness of standard AA2024 alloy and AA2024 alloy with the addition of 1.5% Y after pulsed laser melting (PLM) and selective laser melting (SLM). The SLM process was carried out with a 300 W power and 0.1 m/s laser scanning speed. A dispersed microstructure without the formation of crystallization cracks and low liquation of alloying elements was obtained in Y-modified AA2024 aluminum alloy. Eutectic Al3Y and Al8Cu4Y phases were detected in Y-modified AA2024 aluminum alloy. It is led to a decrease in the formation of crystallization cracks The uniform distribution of alloying elements in the yttrium-modified alloy had a positive effect on the quality of the laser melting zone (LMZ) and microhardness.

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ANISOTROPIC CUTTING FORCE CHARACTERISTICS IN MILLING OF MARAGING STEEL PROCESSED THROUGH SELECTIVE LASER MELTING

Journal of Manufacturing Science and Engineering ◽

10.1115/1.4051920 ◽

2021 ◽

pp. 1-16

Author(s):

Shoichi Tamura ◽

Takashi Matsumura ◽

Atsushi Ezura ◽

Kazuo Mori

Keyword(s):

Additive Manufacturing ◽

Cutting Force ◽

Maraging Steel ◽

Selective Laser Melting ◽

Cutting Forces ◽

Manufacturing Process ◽

Laser Scanning ◽

Force Model ◽

Laser Melting ◽

Scanning Direction

Abstract Additive manufacturing process of maraging steel has been studied for high value parts in aerospace and automotive industries. The hybrid additive / subtractive manufacturing is effective to achieve tight tolerances and surface finishes. The additive process induces anisotropic mechanical properties of maraging steel, which depends on the laser scanning direction. Because anisotropy in the workpiece material has an influence on the cutting process, the surface finish and the dimension accuracy change according to the direction of the cutter feed with respect to the laser scanning direction. Therefore, the cutting parameters should be determined to control the cutting force considering material anisotropy. The paper discusses the cutting force in milling of maraging steel stacked with selective laser melting, as an additive manufacturing process. Anisotropic effect on the cutting forces is proved with the changing rate of the cutting force in milling of the workpieces stacked by repeating laser scanning at 0/90 degrees and 45/-45 degrees. The cutting forces, then, are analyzed in the chip flow models with piling up of orthogonal cuttings. The force model associates anisotropy with the shear stress on the shear plane. The changes in the cutting forces with the feed direction are discussed in the cutting tests and analysis.

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Influence of Scanning Strategies on Processing of Aluminum Alloy EN AW 2618 Using Selective Laser Melting

Materials ◽

10.3390/ma11020298 ◽

2018 ◽

Vol 11 (2) ◽

pp. 298 ◽

Cited By ~ 32

Author(s):

Daniel Koutny ◽

David Palousek ◽

Libor Pantelejev ◽

Christian Hoeller ◽

Rudolf Pichler ◽

...

Keyword(s):

Aluminum Alloy ◽

Selective Laser Melting ◽

Laser Melting ◽

Scanning Strategies

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Anisotropic Cutting Force Characteristics in Milling of Maraging Steel Processed Through Selective Laser Melting

Volume 1: Additive Manufacturing; Advanced Materials Manufacturing; Biomanufacturing; Life Cycle Engineering; Manufacturing Equipment and Automation ◽

10.1115/msec2021-63704 ◽

2021 ◽

Author(s):

Shoichi Tamura ◽

Takashi Matsumura ◽

Atsushi Ezura ◽

Kazuo Mori

Keyword(s):

Additive Manufacturing ◽

Cutting Force ◽

Maraging Steel ◽

Selective Laser Melting ◽

Cutting Forces ◽

Manufacturing Process ◽

Laser Scanning ◽

Force Model ◽

Laser Melting ◽

Scanning Direction

Abstract Additive manufacturing process of maraging steel has been studied for high value parts in aerospace and automotive industries. The hybrid additive / subtractive manufacturing is effective to achieve tight tolerances and surface finishes. The additive process induces anisotropic mechanical properties of maraging steel, which depends on the laser scanning direction. Because anisotropy in the workpiece material has an influence on the cutting process, the surface finish and the dimension accuracy change according to the direction of the cutter feed with respect to the laser scanning direction. Therefore, the cutting parameters should be determined to control the cutting force considering material anisotropy. The paper discusses the cutting force in milling of maraging steel stacked with selective laser melting, as an additive manufacturing process. Anisotropic effect on the cutting forces is proved with the changing rate of the cutting force in milling of the workpieces stacked by repeating laser scanning at 0/90 degrees and 45/−45 degrees. The cutting forces, then, are analyzed in the chip flow models with piling up of orthogonal cuttings. The force model associates anisotropy with the shear stress on the shear plane. The changes in the cutting forces with the feed direction are discussed in the cutting tests and analysis.

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