scholarly journals Process Window for Highly Efficient Laser-Based Powder Bed Fusion of AlSi10Mg with Reduced Pore Formation

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5255
Author(s):  
Artur Leis ◽  
Rudolf Weber ◽  
Thomas Graf
Keyword(s):  
Laser Beam ◽  
Process Efficiency ◽  
Process Window ◽  
Deep Penetration ◽  
Optimum Process ◽  
Beam Diameter ◽  
Powder Bed Fusion ◽  
Powder Bed ◽  
Highly Efficient ◽  
Low Porosity

The process window for highly efficient laser-based powder bed fusion (LPBF), ensuring the production of parts with low porosity, was determined by analyzing cross-sections of samples that were generated with laser powers varying between 10.8 W and 1754 W, laser beam diameters varying between 35 μm and 200 μm, and velocities of the moving laser beam ranging between 0.7 m/s and 1.3 m/s. With these parameters, the process alters between different modes that are referred to as simple heating, heat conduction melting (HCM), key-bowl melting (KBM), and deep-penetration melting (DPM). It was found that the optimum process window for a highly efficient LPBF process, generating AlSi10Mg parts with low porosity, is determined by the ratio PL/db of the incident laser power PL and the beam diameter db of the beam on the surface of the bead, and ranges between PL/db = 2000 W/mm and PL/db = 5200 W/mm, showing process efficiencies of about 7–8%. This optimum process window is centered around the range PL/db = 3000–3500 W/mm, in which the process is characterized by KBM, which is an intermediate process mode between HCM and DPM. Processes with PL/db < 2000 W/mm partially failed, and lead to balling and a lack of fusion, whereas processes with PL/db > 5200 W/mm showed a process efficiency below 5% and pore ratios exceeding 10%.

scholarly journals Carbon Particle In-Situ Alloying of the Case-Hardening Steel 16MnCr5 in Laser Powder Bed Fusion

Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 896
Author(s):  
Matthias Schmitt ◽  
Albin Gottwalt ◽  
Jakob Winkler ◽  
Thomas Tobie ◽  
Georg Schlick ◽  
...  
Keyword(s):  
Laser Beam ◽  
Mechanical Strength ◽  
Carbon Content ◽  
Metal Powder ◽  
Case Hardening ◽  
Powder Bed Fusion ◽  
Powder Bed ◽  
Carbon Particles ◽  
Case Hardening Steel

The carbon content of steel affects many of its essential properties, e.g., hardness and mechanical strength. In the powder bed fusion process of metals using a laser beam (PBF-LB/M), usually, pre-alloyed metal powder is solidified layer-by-layer using a laser beam to create parts. A reduction of the carbon content in steels is observed during this process. This study examines adding carbon particles to the metal powder and in situ alloying in the PBF-LB/M process as a countermeasure. Suitable carbon particles are selected and their effect on the particle size distribution and homogeneity of the mixtures is analysed. The workability in PBF-LB is then shown. This is followed by an evaluation of the resulting mechanical properties (hardness and mechanical strength) and microstructure in the as-built state and the state after heat treatment. Furthermore, potential use cases like multi-material or functionally graded parts are discussed.

Establishing Specimen Property to Part Performance Relationships for Laser Beam Powder Bed Fusion Additive Manufacturing

2021 ◽  
pp. 106384
Author(s):  
Arash Soltani-Tehrani ◽  
Rakish Shrestha ◽  
Nam Phan ◽  
Mohsen Seifi ◽  
Nima Shamsaei
Keyword(s):  
Additive Manufacturing ◽  
Laser Beam ◽  
Powder Bed Fusion ◽  
Powder Bed

scholarly journals Optimizing Laser Powder Bed Fusion Parameters for IN-738LC by Response Surface Method

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4879
Author(s):  
Mireia Vilanova ◽  
Rubén Escribano-García ◽  
Teresa Guraya ◽  
Maria San Sebastian
Keyword(s):  
Response Surface ◽  
Response Surface Method ◽  
Process Parameters ◽  
Crack Density ◽  
Processing Parameters ◽  
Optimum Process ◽  
Powder Bed Fusion ◽  
Laser Powder Bed Fusion ◽  
Powder Bed ◽  
Surface Method

A method to find the optimum process parameters for manufacturing nickel-based superalloy Inconel 738LC by laser powder bed fusion (LPBF) technology is presented. This material is known to form cracks during its processing by LPBF technology; thus, process parameters have to be optimized to get a high quality product. In this work, the objective of the optimization was to obtain samples with fewer pores and cracks. A design of experiments (DoE) technique was implemented to define the reduced set of samples. Each sample was manufactured by LPBF with a specific combination of laser power, laser scan speed, hatch distance and scan strategy parameters. Using the porosity and crack density results obtained from the DoE samples, quadratic models were fitted, which allowed identifying the optimal working point by applying the response surface method (RSM). Finally, five samples with the predicted optimal processing parameters were fabricated. The examination of these samples showed that it was possible to manufacture IN738LC samples free of cracks and with a porosity percentage below 0.1%. Therefore, it was demonstrated that RSM is suitable for obtaining optimum process parameters for IN738LC alloy manufacturing by LPBF technology.

Improvement of Build Speed and Quality of H13 Tool Steel Processed by Laser-Beam Powder Bed Fusion with a High-Power Laser

2021 ◽  
Vol 68 (10) ◽  
pp. 415-421
Author(s):  
Takashi MIZOGUCHI ◽  
Takaya NAGAHAMA ◽  
Makoto TANO ◽  
Shigeru MATSUNAGA ◽  
Takayuki YOSHIMI ◽  
...  
Keyword(s):  
Laser Beam ◽  
Tool Steel ◽  
High Power ◽  
Powder Bed Fusion ◽  
High Power Laser ◽  
Power Laser ◽  
Powder Bed ◽  
H13 Tool Steel

scholarly journals Roadmap for Additive Manufacturing of Haynes® 282® Superalloy by Laser Beam Powder Bed Fusion (PBF-LB) Technology

2020 ◽  
Author(s):  
Robert Otto ◽  
Vegard Brøtan ◽  
Patricia Almeida Carvalho ◽  
Magnus Reiersen ◽  
Joachim Seland Graff ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Laser Beam ◽  
Powder Bed Fusion ◽  
Powder Bed

scholarly journals PBF-LB Process-Induced Regular Cavities for Lightweight AlSi10Mg Structures

Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6665
Author(s):  
Victor Lubkowitz ◽  
Jonas Alber ◽  
Frederik Zanger
Keyword(s):  
Laser Beam ◽  
Pore Formation ◽  
Powder Bed Fusion ◽  
Powder Bed ◽  
Lack Of Fusion ◽  
Keyhole Effect ◽  
Pore Types ◽  
Induced Defects

In powder bed fusion with laser beam (PBF-LB), two process-induced defects by pore formation are known: local spherical pores by the keyhole effect and geometrically undefined pores caused by lack of fusion. Both pore types are heterogeneously distributed and can be used for lightweight or damping design applications. The achievable porosity is limited to around 13%. This article presents a novel process-controlled method enabling the targeted and reproducible manufacturing of solid parts with regularly distributed cavities, currently up to 60% porosity in AlSi10Mg, using the balling effect. This eliminates the need for time-consuming digital pre-processing work.

In-Situ Monitoring of Laser Powder Bed Fusion Process Anomalies via a Comprehensive Analysis of Off-Axis Camera Data

2020 ◽  
Author(s):  
Chaitanya Krishna Prasad Vallabh ◽  
Yubo Xiong ◽  
Xiayun Zhao
Keyword(s):  
Real Time ◽  
Network Architecture ◽  
Video Data ◽  
In Situ Monitoring ◽  
Process Efficiency ◽  
Powder Bed Fusion ◽  
Laser Powder Bed Fusion ◽  
Monitoring Method ◽  
Powder Bed

Abstract In-situ monitoring of a Laser Powder-Bed Fusion (LPBF) additive manufacturing process is crucial in enhancing the process efficiency and ensuring the built part integrity. In this work, we present an in-situ monitoring method using an off-axis camera for monitoring layer-wise process anomalies. The in-situ monitoring is performed with a spatial resolution of 512 × 512 pixels, with each pixel representing 250 × 250 μm and a relatively high data acquisition rate of 500 Hz. An experimental study is conducted by using the developed in-situ off-axis method for monitoring the build process for a standard tensile bar. Real-time video data is acquired for each printed layer. Data analytics methods are developed to identify layer-wise anomalies, observe powder bed characteristics, reconstruct 3D part structure, and track the spatter dynamics. A deep neural network architecture is trained using the acquired layer-wise images and tested by images embedded with artificial anomalies. The real-time video data is also used to perform a preliminary spatter analysis along the laser scan path. The developed methodology is aimed to extract as much information as possible from a single set of camera video data. It will provide the AM community with an efficient and capable process monitoring tool for process control and quality assurance while using LPBF to produce high-standard components in industrial (such as, aerospace and biomedical industries) applications.

scholarly journals Influence of process gas during powder bed fusion with laser beam of Zr-based bulk metallic glasses

Procedia CIRP ◽  
2020 ◽  
Vol 94 ◽  
pp. 205-210
Author(s):  
Jan Wegner ◽  
Maximilian Frey ◽  
Stefan Kleszczynski ◽  
Ralf Busch ◽  
Gerd Witt
Keyword(s):  
Laser Beam ◽  
Metallic Glasses ◽  
Bulk Metallic Glasses ◽  
Powder Bed Fusion ◽  
Powder Bed ◽  
Process Gas

scholarly journals Microstructural control in metal laser powder bed fusion additive manufacturing using laser beam shaping strategy

2020 ◽  
Vol 184 ◽  
pp. 284-305 ◽  
Author(s):  
Rongpei Shi ◽  
Saad A. Khairallah ◽  
Tien T. Roehling ◽  
Tae Wook Heo ◽  
Joseph T. McKeown ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Laser Beam ◽  
Beam Shaping ◽  
Powder Bed Fusion ◽  
Laser Powder Bed Fusion ◽  
Laser Beam Shaping ◽  
Powder Bed ◽  
Microstructural Control
Sign in / Sign up

Export Citation Format

Share Document