scholarly journals Defect Prevention in Selective Laser Melting Components: Compositional and Process Effects

Materials ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 3791 ◽  
Author(s):  
Hossein Eskandari Sabzi ◽  
Pedro E. J. Rivera-Díaz-del-Castillo
Keyword(s):  
Selective Laser Melting ◽  
Thermal Stresses ◽  
Defect Formation ◽  
Austenitic Stainless Steels ◽  
Melting Process ◽  
Physical Analysis ◽  
Laser Melting ◽  
Solidification Temperature ◽  
Process Effects ◽  
Defect Prevention

A model to predict the conditions for printability is presented. The model focuses on crack prevention, as well as on avoiding the formation of defects such as keyholes, balls and lack of fusion. Crack prevention is ensured by controlling the solidification temperature range and path, as well as via quantifying its ability to resist thermal stresses upon solidification. Defect formation prevention is ensured by controlling the melt pool geometry and by taking into consideration the melting properties. The model’s core relies on thermodynamics and physical analysis to ensure optimal printability, and in turn offers key information for alloy design and selective laser melting process control. The model is shown to describe accurately defect formation of 316L austenitic stainless steels reported in the literature.

Finite Element Analysis to Improve the Accuracy of Parts Made by Stainless Steel 316L Material Using Selective Laser Melting Technology

2014 ◽  
Vol 657 ◽  
pp. 236-240 ◽  
Author(s):  
Razvan Păcurar ◽  
Ancuţa Păcurar
Keyword(s):  
Finite Element ◽  
Stainless Steel ◽  
Selective Laser Melting ◽  
Thermal Stresses ◽  
Melting Process ◽  
Optimum Process ◽  
Stainless Steel 316L ◽  
Laser Melting ◽  
Element Analysis ◽  
Bed Temperature

One of the serious problems in the SLM process, using metallic powders is the thermal distortion of the model during forming. As a result of the locally concentrated energy input, the temperature gradient mechanism and the related processes lead to residual stresses and part deformations. Since the solidified part is cooled rapidly, the model tends to be deformed and cracked due to the thermal stresses. All these aspects were considered for a series of analyses that were made using the finite element method in order to determine the optimum process parameters (laser power, scanning speed, powder bed temperature) that are required in order to improve the accuracy of the metallic parts made by Stainless Steel 316L material using the Selective Laser Melting process.

scholarly journals Prosthetic Elements Made of the Ti-13Zr-13Nb Alloy by Selective Laser Melting

2017 ◽  
Vol 17 (3) ◽  
pp. 54-61 ◽  
Author(s):  
T. Seramak ◽  
K. Zasińska ◽  
A. Zieliński ◽  
J. Andryskowski ◽  
A. Andryskowska-Ignaczak ◽  
...  
Keyword(s):  
Selective Laser Melting ◽  
Thermal Stresses ◽  
Melting Process ◽  
3D Models ◽  
Design Stage ◽  
Laser Melting ◽  
Intrinsic Structure ◽  
Cad Cam ◽  
Manufacturing Stage ◽  
Proper Setting

Abstract The fabrication of the prosthetic foundations and bridges from the Ti-13Zr-13Nb alloy is described. The process was started from CAD/CAM design of 3D models of the foundations based on scanning of patient’s mouth. Next, 3D models were transformed into *.stl files for the manufacturing stage and then the manufacturing process by means of the selective laser melting with the SLM Realizer 100 equipment was made. The intrinsic structure of the obtained parts was investigated with X-ray microtomography. The observed imperfections in the foundation's internal structure can be eliminated by a proper setting of the laser melting process. The thermal stresses, which resulted of the temperature change during melting and caused the bending of titanium made bridges, were eliminated at a design stage.

scholarly journals Improving surface quality in selective laser melting based tool making

2021 ◽  
Author(s):  
Filippo Simoni ◽  
Andrea Huxol ◽  
Franz-Josef Villmer
Keyword(s):  
Surface Roughness ◽  
Additive Manufacturing ◽  
Surface Quality ◽  
Selective Laser Melting ◽  
Melting Process ◽  
Laser Remelting ◽  
Laser Melting ◽  
Great Cost ◽  
Starting Point ◽  
Processing Techniques

AbstractIn the last years, Additive Manufacturing, thanks to its capability of continuous improvements in performance and cost-efficiency, was able to partly replace and redefine well-established manufacturing processes. This research is based on the idea to achieve great cost and operational benefits especially in the field of tool making for injection molding by combining traditional and additive manufacturing in one process chain. Special attention is given to the surface quality in terms of surface roughness and its optimization directly in the Selective Laser Melting process. This article presents the possibility for a remelting process of the SLM parts as a way to optimize the surfaces of the produced parts. The influence of laser remelting on the surface roughness of the parts is analyzed while varying machine parameters like laser power and scan settings. Laser remelting with optimized parameter settings considerably improves the surface quality of SLM parts and is a great starting point for further post-processing techniques, which require a low initial value of surface roughness.

scholarly journals Fabrication of Mesh Patterns Using a Selective Laser-Melting Process

2019 ◽  
Vol 9 (9) ◽  
pp. 1922 ◽  
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.

scholarly journals Selective Laser Melting Process of Al–Based Pyramidal Horns for the W-Band: Fabrication and Testing

2021 ◽  
Author(s):  
L. Lamagna ◽  
A. Paiella ◽  
S. Masi ◽  
L. Bottini ◽  
A. Boschetto ◽  
...  
Keyword(s):  
Selective Laser Melting ◽  
High Surface ◽  
Melting Process ◽  
Horn Antenna ◽  
Post Processing ◽  
Laser Melting ◽  
Performance Impact ◽  
Horn Antennas ◽  
Sand Blasting ◽  
W Band

AbstractIn the context of exploring the possibility of using Al-powder Selective Laser Melting to fabricate horn antennas for astronomical applications at millimeter wavelengths, we describe the design, the fabrication, the mechanical characterization, and the electromagnetic performance of additive manufactured horn antennas for the W-band. Our aim, in particular, is to evaluate the performance impact of two basic kinds of surface post-processing (manual grinding and sand-blasting) to deal with the well-known issue of high surface roughness in 3D printed devices. We performed comparative tests of co-polar and cross-polar angular response across the whole W-band, assuming a commercially available rectangular horn antenna as a reference. Based on gain and directivity measurements of the manufactured samples, we find decibel-level detectable deviations from the behavior of the reference horn antenna, and marginal evidence of performance degradation at the top edge of the W-band. We conclude that both kinds of post-processing allow achieving good performance for the W-band, but the higher reliability and uniformity of the sand-blasting post-process encourage exploring similar techniques for further development of aluminum devices at these frequencies.

Fabrication and mechanical properties of Al–Si-based alloys by selective laser melting process

2021 ◽  
pp. 1-8
Author(s):  
Yeong Seong Eom ◽  
Kyung Tae Kim ◽  
Dong Won Kim ◽  
Soo ho Jung ◽  
Jung Woo Nam ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Selective Laser Melting ◽  
Melting Process ◽  
Laser Melting ◽  
Selective Laser Melting Process

A study on the effect of energy input on spatter particles creation during selective laser melting process

2018 ◽  
Vol 20 ◽  
pp. 33-43 ◽  
Author(s):  
Mohsen Taheri Andani ◽  
Reza Dehghani ◽  
Mohammad Reza Karamooz-Ravari ◽  
Reza Mirzaeifar ◽  
Jun Ni
Keyword(s):  
Selective Laser Melting ◽  
Energy Input ◽  
Melting Process ◽  
Laser Melting ◽  
Selective Laser Melting Process
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