Powder Bed Fusion Additive Manufacturing of Ni-Based Superalloys

2020 ◽  
pp. 249-270
Author(s):  
Evren Yasa ◽  
Ozgur Poyraz
Keyword(s):  
Additive Manufacturing ◽  
Material Properties ◽  
Elevated Temperatures ◽  
Design Criteria ◽  
Complex Geometries ◽  
Powder Bed Fusion ◽  
Powder Bed ◽  
Volume Production ◽  
Manufacturing Technologies ◽  
Aerospace And Defense

Emerging additive manufacturing technologies have been gaining interest from different industries and widened their fields of application among aerospace and defense. The introduction of powder bed fusion processes was one of the significant developments in terms of direct metal part manufacturing of different materials and complex geometries, presenting good properties, and decreasing the need for tooling to allow fast product development as well as small-volume production. In this respect, nickel-based superalloys are one of the most employed material groups for aerospace and defense applications due to their mechanical strength, creep, wear, and oxidation resistance at both ambient and elevated temperatures. Nevertheless, the use of some materials has not become widespread due to several reasons such as processing difficulties, absence of design criteria or material properties. This chapter presents a comprehensive benchmark for powder bed fusion additive manufacturing of nickel-based superalloys considering applications, characteristics, and limitations.

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.

Hybride Fertigung mittels Laser-Strahlschmelzen/Hybrid manufacturing by laser-based powder bed fusion

2021 ◽  
Vol 111 (06) ◽  
pp. 363-367
Author(s):  
Lukas Langer ◽  
Matthias Schmitt ◽  
Georg Schlick ◽  
Johannes Schilp
Keyword(s):  
Additive Manufacturing ◽  
Manufacturing Processes ◽  
Complex Geometries ◽  
Hybrid Manufacturing ◽  
Powder Bed Fusion ◽  
Process Chain ◽  
Manufacturing Costs ◽  
Additive Fertigung ◽  
Powder Bed

Die additive Fertigung ermöglicht komplexe Geometrien und individualisierte Bauteile. Die hohen Material- und Fertigungskosten können ein Hindernis für einen wirtschaftlichen Einsatz sein. In der hybriden additiven Fertigung werden die Vorteile konventioneller sowie additiver Fertigungsverfahren kombiniert. Für eine weitere Steigerung der Wirtschaftlichkeit und Effizienz werden nichtwertschöpfende Schritte der Prozesskette identifiziert und Automatisierungsansätze entwickelt.   Additive manufacturing enables complex geometries and individualized components. However, high material and manufacturing costs can be a hindrance for economical use. Hybrid additive manufacturing combines the advantages of conventional with additive manufacturing processes. For a further increase in profitability and efficiency, non-value-adding steps in the process chain are identified and automation approaches developed.

Evaluation of the Material Properties of the Ti and CoCr Alloys Prepared by Laser Powder Bed Fusion

2020 ◽  
Vol 985 ◽  
pp. 223-228
Author(s):  
Jana Bidulská ◽  
Róbert Bidulský ◽  
Patrik Petrouse ◽  
Tibor Kvačkaj ◽  
Marco Actis Grande ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Image Analysis ◽  
Additive Manufacturing ◽  
Material Properties ◽  
Ti6al4v Alloy ◽  
Homogeneous Distribution ◽  
Powder Bed Fusion ◽  
Laser Powder Bed Fusion ◽  
Powder Bed ◽  
Quantitative Image

The main aim of the present paper is evaluated the mechanical properties, microstructures and porosity of Ti6Al4V and CoCrW alloys produced by Laser Powder Bed Fusion (L-PBF) as an additive manufacturing (AM) technology. The mechanical properties were follows: For Ti6Al4V alloy the UTS was 1180 MPa; the YS was in the range <600; 745 MPa>. For CoCrW alloys, the UTS were in range <750; 950 MPa> and YS was in range <400; 500>. Evaluation of porosity was realized on non-etched samples using by quantitative image analysis in order to describe the dimensional and morphological porosity characteristics. The pores in the Ti6Al4V alloy showed homogeneous distribution without significant large pores.

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.

Integration of piezoelectric stacks in components using powder bed fusion

2021 ◽  
Author(s):  
Rico Weber ◽  
Samuel Seydel ◽  
Adriaan Spierings ◽  
Andrea Bergamini ◽  
Bart Van Damme ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Piezoelectric Materials ◽  
High Amplitude ◽  
Complex Geometries ◽  
Damping Factor ◽  
Laser Vibrometer ◽  
Powder Bed Fusion ◽  
Powder Bed ◽  
Piezoelectric Stacks ◽  
High Level

Abstract Laser-based powder bed fusion of metals (PBF-LB/M) is the most commonly used additive manufacturing process for fabricating complex metal parts by selective, layer-wise melting of metallic powder using a laser beam. This manufacturing technique can easily fabricate parts with complex geometries that cannot be fabricated using conventional manufacturing processes. These parts with complex geometries are generally used by aerospace and space industries, and advancement in functionalization of additive manufactured parts is highly beneficial to these industries. However, the parts constructed using additive manufacturing are monolithic, stiff, and lightweight and hence, they are vulnerable to high amplitude resonant vibrations. This is due to the low damping factor of the materials used and the absence of interfaces and connections that contribute to structural damping in conventional structures. The integration of piezoelectric materials within these structures would enable the control of vibration characteristics. The techniques presented in this study will enable a high level of freedom in the placement of piezoelectric materials and investigate the potential of merging parts constructed using additive manufacturing with piezoelectric materials. Furthermore, a technique to track the stress state during the integration process, which is crucial for the pre-stress evaluation of integrated piezoelectric stacks, is presented and shows characteristics similar to a force cell. Pre-stress is successfully tracked during integration and in some concepts tensile stress onto the piezoelectric material is occurring. Finally, to verify the functionality for potential piezoelectric damping, power conversion was reported with laser vibrometer measurements and FE validation.

scholarly journals On The Relation Between Cooling Rate and Parts Geometry in Powder Bed Fusion Additive Manufacturing

2018 ◽  
Vol 1 (1) ◽  
pp. 223-231
Author(s):  
Nihat Yilmaz ◽  
Mevlüt Yunus Kayacan
Keyword(s):  
Additive Manufacturing ◽  
Cooling Rate ◽  
Solidification Process ◽  
Internal Stresses ◽  
Layer By Layer ◽  
Powder Bed Fusion ◽  
Metal Powders ◽  
Powder Bed ◽  
Powder Particles ◽  
Manufacturing Technologies

Direct metal laser sintering (DMLS), one of the laser powder bed additive manufacturing technologies produces solid metal parts from 3-D CAD data, layer by layer, by melting/sintering and bonding metal powders with a focused laser beam. In this processes isn&apos;t complete melting of powder particles in micro melt pools as well as selective laser melting (SLM) and electron beam melting (EBM). Thus some different stress conditions and defects occur depending on the temperature changes during manufacturing. In this study, this problems is investigated aspect cooling rate. Cooling rate affects the solidification process in the melting (sintering) process such as casting, welding, laser assisted processes. Therefore, it also affect part quality and properties. In the scope of study, it is tried to explain how occurring the internal stresses and distortions differ depending on the cooling rates of geometrically different parts in additive manufacturing. The residual stresses and deformations are analyzed by FEA to see relation with geometry (volume, area) to cooling rate for Ti6Al4V materials. Cube shaped samples at 20, 40, 60, 80 and 100 mm edge dimensions have analysed by using FEA. Besides 10mm cube sample is manufactured as solid and verified both as experimental and numerical. Based on the FEA results, cooling rate values are changed from 1.67 to 16.67. In conclusion, the reasons of the problems occurring during laser powder bed fusion are investigated in terms of the cooling rate in relation with the samples geometry.

scholarly journals Axiomatic Design of Test Artifact for Laser Powder Bed Fusion Machine Capability Assessment

2019 ◽  
Vol 301 ◽  
pp. 00006 ◽  
Author(s):  
Alessandro Giorgetti ◽  
Filippo Ceccanti ◽  
Paolo Citti ◽  
Andrea Ciappi ◽  
Gabriele Arcidiacono
Keyword(s):  
Additive Manufacturing ◽  
Axiomatic Design ◽  
Powder Bed Fusion ◽  
Laser Powder Bed Fusion ◽  
Powder Bed ◽  
Complex Product ◽  
Machine Performance ◽  
Performance Check ◽  
Improved Design ◽  
Manufacturing Technologies

Additive Manufacturing is increasingly growing in importance in the manufacturing environment, allowing to realize very complex product designs. Identifying the real machine capability is becoming fundamental as additive manufacturing technologies are starting to substitute conventional manufacturing processes. This aspect holds particularly true in the case of Laser Powder Bed Fusion technology. In this case, the method to investigate and determine the actual machine capabilities still represents an open point. In this paper, we propose an analysis of a well-known test artifact from an Axiomatic Design standpoint; based on the results and the review of the Customer Needs, we develop an improved design which is able to ensure a robust analysis for a reliable machine performance check.

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