scholarly journals Development of Laser-Based Powder Bed Fusion Process Parameters and Scanning Strategy for New Metal Alloy Grades: A Holistic Method Formulation

Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2356 ◽  
Author(s):  
Elena Bassoli ◽  
Antonella Sola ◽  
Mattia Celesti ◽  
Sandro Calcagnile ◽  
Carlo Cavallini
Keyword(s):  
Processing Parameters ◽  
Powder Bed Fusion ◽  
Scanning Strategy ◽  
Industrial Practice ◽  
Powder Bed ◽  
Complete Test ◽  
Specific Geometry ◽  
Method Formulation ◽  
Definition Of ◽  
Standard Energy

In spite of the fast growth of laser-based powder bed fusion (L-PBF) processes as a part of everyday industrial practice, achieving consistent production is hampered by the scarce repeatability of performance that is often encountered across different additive manufacturing (AM) machines. In addition, the development of novel feedstock materials, which is fundamental to the future growth of AM, is limited by the absence of established methodologies for their successful exploitation. This paper proposes a structured procedure with a complete test plan, which defines step-by-step the standardized actions that should be taken to optimize the processing parameters and scanning strategy in L-PBF of new alloy grades. The method is holistic, since it considers all the laser/material interactions in different local geometries of the build, and suggests, for each possible interaction, a specific geometry for test specimens, standard energy parameters to be analyzed through a design of experiment, and measurable key performance indicators. The proposed procedure therefore represents a sound and robust aid to the development of novel alloy grades for L-PBF and to the definition of the most appropriate processing conditions for them, independent of the specific AM machine applied.

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.

scholarly journals A Review of Factors Affecting the Mechanical Properties of Maraging Steel 300 Fabricated via Laser Powder Bed Fusion

Metals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1273 ◽  
Author(s):  
Barry Mooney ◽  
Kyriakos Kourousis
Keyword(s):  
Mechanical Properties ◽  
Maraging Steel ◽  
Processing Parameters ◽  
Powder Bed Fusion ◽  
Laser Powder Bed Fusion ◽  
Factors Affecting ◽  
Powder Bed ◽  
Porosity Defects ◽  
Research Findings ◽  
Microstructure Density

Maraging steel is an engineering alloy which has been widely employed in metal additive manufacturing. This paper examines manufacturing and post-processing factors affecting the properties of maraging steel fabricated via laser powder bed fusion (L-PBF). It covers the review of published research findings on how powder quality feedstock, processing parameters, laser scan strategy, build orientation and heat treatment can influence the microstructure, density and porosity, defects and residual stresses developed on L-PBF maraging steel, with a focus on the maraging steel 300 alloy. This review offers an evaluation of the resulting mechanical properties of the as-built and heat-treated maraging steel 300, with a focus on anisotropic characteristics. Possible directions for further research are also identified.

scholarly journals Setting the Optimal Laser Power for Sustainable Powder Bed Fusion Processing of Elastomeric Polyesters: A Combined Experimental and Theoretical Study

Materials ◽  
2022 ◽  
Vol 15 (1) ◽  
pp. 385
Author(s):  
Ruben Vande Ryse ◽  
Mariya Edeleva ◽  
Ortwijn Van Stichel ◽  
Dagmar R. D’hooge ◽  
Frederik Pille ◽  
...  
Keyword(s):  
Laser Power ◽  
Theoretical Study ◽  
Selective Laser Sintering ◽  
Polymeric Materials ◽  
Thermoplastic Elastomer ◽  
Processing Parameters ◽  
Operating Conditions ◽  
Powder Bed Fusion ◽  
Powder Bed ◽  
Bed Temperature

Additive manufacturing (AM) of polymeric materials offers many benefits, from rapid prototyping to the production of end-use material parts. Powder bed fusion (PBF), more specifically selective laser sintering (SLS), is a very promising AM technology. However, up until now, most SLS research has been directed toward polyamide powders. In addition, only basic models have been put forward that are less directed to the identification of the most suited operating conditions in a sustainable production context. In the present combined experimental and theoretical study, the impacts of several SLS processing parameters (e.g., laser power, part bed temperature, and layer thickness) are investigated for a thermoplastic elastomer polyester by means of colorimetric, morphological, physical, and mechanical analysis of the printed parts. It is shown that an optimal SLS processing window exists in which the printed polyester material presents a higher density and better mechanical properties as well as a low yellowing index, specifically upon using a laser power of 17–20 W. It is further highlighted that the current models are not accurate enough at predicting the laser power at which thermal degradation occurs. Updated and more fundamental equations are therefore proposed, and guidelines are formulated to better assess the laser power for degradation and the maximal temperature achieved during sintering. This is performed by employing the reflection and absorbance of the laser light and taking into account the particle size distribution of the powder material.

scholarly journals The residual stress in as-built Laser Powder Bed Fusion IN718 alloy as a consequence of the scanning strategy induced microstructure

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Itziar Serrano-Munoz ◽  
Tatiana Mishurova ◽  
Tobias Thiede ◽  
Maximilian Sprengel ◽  
Arne Kromm ◽  
...  
Keyword(s):  
Residual Stress ◽  
Powder Bed Fusion ◽  
Laser Powder Bed Fusion ◽  
Scanning Strategy ◽  
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).

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