Additive Manufacturing of Honeycombs Seal Strips

2018 ◽  
Author(s):  
Ole Geisen ◽  
Lisa Kersting ◽  
Lukas Masseling ◽  
Jan Pascal Bogner ◽  
Johannes Henrich Schleifenbaum
Keyword(s):  
Additive Manufacturing ◽  
Gas Turbines ◽  
Process Development ◽  
Three Dimensional ◽  
Parameter Study ◽  
Powder Bed ◽  
Require Time ◽  
Need For Support ◽  
Assembly Operations ◽  
High Degree

Laser-Powder Bed Fusion (L-PBF) is an additive manufacturing technique used to melt metal material into solid three-dimensional parts. While offering a high degree of design freedom, L-PBF still has technical restrictions, like the achievable surface roughness, resolution and the need for support structures in overhanging areas. [1] Currently, L-PBF is used mainly to produce small batches of parts and prototypes. [2] In order to fully industrialize the technology, the research campus in Aachen is investigating possible future applications in turbomachinery while developing the corresponding processes with industry partners. Sealing systems, like honeycomb seal strips in gas turbines often require time-consuming joining and assembly operations that can be avoided by building up the structure monolithically using L-PBF. The following process development study proves the feasibility of manufacturing honeycombs with L-PBF using the Nickel-based super-alloy Inconel 718 (IN718) on an EOS M290 machine. Here, we have evaluated the economic aspects of different build orientations of the seal strips. Afterwards, we conducted a systematic parameter study with continuous and pulsed wave laser emission and investigated the resulting wall thicknesses. A reduction in wall thickness of about 30% can be observed when a modulated laser is used.

Binder jetting additive manufacturing: Three-dimensional simulation of micro-meter droplet impact and penetration into powder bed

2022 ◽  
Vol 74 ◽  
pp. 365-373
Author(s):  
Hongxin Deng ◽  
Yanlu Huang ◽  
Shibiao Wu ◽  
Yongqiang Yang
Keyword(s):  
Additive Manufacturing ◽  
Three Dimensional ◽  
Droplet Impact ◽  
Powder Bed ◽  
Dimensional Simulation ◽  
Binder Jetting

Establishment of a Competitive Additive Manufacturing Workshop

2016 ◽  
Author(s):  
Paul Ryan ◽  
Jan Schwerdtfeger ◽  
Markus Rodermann
Keyword(s):  
Additive Manufacturing ◽  
Gas Turbines ◽  
High Performance ◽  
Best Practice ◽  
Process Development ◽  
Process Efficiency ◽  
Development Effort ◽  
Industrial Gas Turbines ◽  
High Level ◽  
Design And Manufacture

Compared to conventional manufacturing processes, additive manufacturing offers a degree of freedom that has the potential to revolutionize the turbine components supply chain. Additive manufacturing facilitates the design and manufacture of highly complex components in high performance materials with features that cannot currently be realized with other processes. In addition, shorter development and manufacturing lead-times are possible due to the flexibility of 3D based processing and the absence of expensive, complicated molds or dies. Having been confined for many years to rapid prototyping or R&D applications, additive manufacturing is now making the move to the factory floor. However, a dearth of manufacturing experience makes the development effort and risk of costly mistakes a deterrent for many organizations that would otherwise be interested in exploring the benefits of additive manufacturing. A former manufacturer of industrial gas turbines recently established an additive manufacturing workshop designed to deliver highly complex engine-ready components that can contribute to increased performance of the gas turbine. A strong emphasis on process validation and implementation of the organization’s best practice Lean and Quality methodologies has laid solid foundations for a highly capable manufacturing environment. This paper describes the approach taken to ensure that the workshop achieves a high level of operational excellence. Process development topics explored in the paper include the following: • Planning of process flow and cell layout to permit the maximum lean performance • Strategy used to determine machine specification and selection method. • Assessment of process capability • Influence of design for manufacture on process efficiency and product quality • Experience gained during actual production of first commercial components

Performance of Public Film Cooling Geometries Produced Through Additive Manufacturing

2020 ◽  
Vol 142 (5) ◽  
Author(s):  
Jacob C. Snyder ◽  
Karen A. Thole
Keyword(s):  
Additive Manufacturing ◽  
Film Cooling ◽  
Gas Turbines ◽  
Nickel Alloys ◽  
Cooling Effectiveness ◽  
Powder Bed ◽  
The Public ◽  
Hot Gas ◽  
Cooling Hole ◽  
Cooling Technology

Abstract Film cooling is an essential cooling technology to allow modern gas turbines to operate at high temperatures. For years, researchers in this community have worked to improve the effectiveness of film cooling configurations by maximizing the coolant coverage and minimizing the heat flux from the hot gas into the part. Working toward this goal has generated many promising film cooling concepts with unique shapes and configurations. However, until recently, many of these designs were challenging to manufacture in actual turbine hardware due to limitations with legacy manufacturing methods. Now, with the advances in additive manufacturing, it is possible to create turbine parts using high-temperature nickel alloys that feature detailed and unique geometry features. Armed with this new manufacturing power, this study aims to build and test the promising designs from the public literature that were previously difficult or impossible to implement. In this study, different cooling hole designs were manufactured in test coupons using a laser powder bed fusion process. Each nickel alloy coupon featured a single row of engine scale cooling holes, fed by a microchannel. To evaluate performance, the overall cooling effectiveness of each coupon was measured using a matched Biot test at engine relevant conditions. The results showed that certain hole shapes are better suited for additive manufacturing than others and that the manufacturing process can cause significant deviations from the performance reported in the literature.

scholarly journals Material Reuse in Laser Powder Bed Fusion: Side Effects of the Laser—Metal Powder Interaction

Metals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 341 ◽  
Author(s):  
Eleonora Santecchia ◽  
Stefano Spigarelli ◽  
Marcello Cabibbo
Keyword(s):  
Additive Manufacturing ◽  
Side Effects ◽  
Metal Powder ◽  
Three Dimensional ◽  
High Energy ◽  
Powder Bed Fusion ◽  
Laser Powder Bed Fusion ◽  
Powder Bed ◽  
Metal Additive Manufacturing ◽  
Metal Additive

Metal additive manufacturing is changing the way in which engineers and designers model the production of three-dimensional (3D) objects, with rapid growth seen in recent years. Laser powder bed fusion (LPBF) is the most used metal additive manufacturing technique, and it is based on the efficient interaction between a high-energy laser and a metal powder feedstock. To make LPBF more cost-efficient and environmentally friendly, it is of paramount importance to recycle (reuse) the unfused powder from a build job. However, since the laser–powder interaction involves complex physics phenomena and generates by-products which might affect the integrity of the feedstock and the final build part, a better understanding of the overall process should be attained. The present review paper is focused on the clarification of the interaction between laser and metal powder, with a strong focus on its side effects.

scholarly journals Review of Powder Bed Fusion Additive Manufacturing for Metals

Metals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1391
Author(s):  
Leila Ladani ◽  
Maryam Sadeghilaridjani
Keyword(s):  
Additive Manufacturing ◽  
Three Dimensional ◽  
Disruptive Technology ◽  
Powder Bed ◽  
Powder Particles ◽  
Metallic Parts ◽  
The Cost ◽  
Scientific Questions ◽  
Metal Additive

Additive manufacturing (AM) as a disruptive technology has received much attention in recent years. In practice, however, much effort is focused on the AM of polymers. It is comparatively more expensive and more challenging to additively manufacture metallic parts due to their high temperature, the cost of producing powders, and capital outlays for metal additive manufacturing equipment. The main technology currently used by numerous companies in the aerospace and biomedical sectors to fabricate metallic parts is powder bed technology, in which either electron or laser beams are used to melt and fuse the powder particles line by line to make a three-dimensional part. Since this technology is new and also sought by manufacturers, many scientific questions have arisen that need to be answered. This manuscript gives an introduction to the technology and common materials and applications. Furthermore, the microstructure and quality of parts made using powder bed technology for several materials that are commonly fabricated using this technology are reviewed and the effects of several process parameters investigated in the literature are examined. New advances in fabricating highly conductive metals such as copper and aluminum are discussed and potential for future improvements is explored.

Thermofluid Properties of Ti-6Al-4V Melt Pool in Powder-Bed Electron Beam Additive Manufacturing

2019 ◽  
Vol 141 (4) ◽  
Author(s):  
M Shafiqur Rahman ◽  
Paul J. Schilling ◽  
Paul D. Herrington ◽  
Uttam K. Chakravarty
Keyword(s):  
Electron Beam ◽  
Additive Manufacturing ◽  
Heat Source ◽  
Thermal Behavior ◽  
Source Parameters ◽  
Three Dimensional ◽  
Full Density ◽  
Layer By Layer ◽  
Powder Bed ◽  
Melt Pool

Electron beam additive manufacturing (EBAM) is a powder-bed fusion additive manufacturing (AM) technology that can make full density metallic components using a layer-by-layer fabrication method. To build each layer, the EBAM process includes powder spreading, preheating, melting, and solidification. The quality of the build part, process reliability, and energy efficiency depends typically on the thermal behavior, material properties, and heat source parameters involved in the EBAM process. Therefore, characterizing those properties and understanding the correlations among the process parameters are essential to evaluate the performance of the EBAM process. In this study, a three-dimensional computational fluid dynamics (CFD) model with Ti-6Al-4V powder was developed incorporating the temperature-dependent thermal properties and a moving conical volumetric heat source with Gaussian distribution to conduct the simulations of the EBAM process. The melt pool dynamics and its thermal behavior were investigated numerically, and results for temperature profile, melt pool geometry, cooling rate and variation in density, thermal conductivity, specific heat capacity, and enthalpy were obtained for several sets of electron beam specifications. Validation of the model was performed by comparing the simulation results with the experimental results for the size of the melt pool.

Thermal Analysis of Electron Beam Additive Manufacturing Using Ti-6Al-4V Powder-Bed

2017 ◽  
Author(s):  
M. Shafiqur Rahman ◽  
Paul J. Schilling ◽  
Paul D. Herrington ◽  
Uttam K. Chakravarty
Keyword(s):  
Electron Beam ◽  
Additive Manufacturing ◽  
Three Dimensional ◽  
Vital Role ◽  
Full Density ◽  
Rate Variation ◽  
Layer By Layer ◽  
Powder Bed ◽  
Part Quality ◽  
Melt Pool

Electron Beam Additive Manufacturing (EBAM) is one of the emerging additive manufacturing (AM) technologies that is uniquely capable of making full density metallic components using layer-by-layer fabrication method. To build each layer, the process includes powder spreading, pre-heating, melting, and solidification. The thermal and material properties involved in the EBAM process play a vital role to determine the part quality, reliability, and energy efficiency. Therefore, characterizing the properties and understanding the correlations among the process parameters are incumbent to evaluate the performance of the EBAM process. In this study, a three dimensional computational fluid dynamics (CFD) model with Ti-6Al-4V powder has been developed incorporating the temperature-dependent thermal properties and a moving conical volumetric heat source with Gaussian distribution to conduct the simulations of the EBAM process. The melt-pool dynamics and its thermal behavior have been investigated numerically using a CFD solver and results for temperature profile, cooling rate, variation in density, thermal conductivity, specific heat capacity, and enthalpy have been obtained for a particular set of electron beam specifications.

Design for Additive Manufacturing: Valves Without Moving Parts

2017 ◽  
Author(s):  
A. Gaymann ◽  
F. Montomoli ◽  
M. Pietropaoli
Keyword(s):  
Additive Manufacturing ◽  
Gas Turbines ◽  
Design Method ◽  
Three Dimensional ◽  
Automatic Generation ◽  
Two Dimensions ◽  
Steepest Descent Method ◽  
Wide Range ◽  
Tesla Valve ◽  
Moving Parts

This work presents an innovative design method to obtain valves without moving parts that can be built using additive manufacturing and applied to gas turbines. Additive manufacturing offers more flexibility than traditional manufacturing methods, which implies less constraints on the manufacture of engineering parts and it is possible to build complex geometries like the Tesla valve. The Tesla valve is a duct that shows a diodicity behavior: it allows a fluid to flow in one direction with lower losses than in the other one. Unfortunately the design of the Tesla valve is two dimensional and it relies on the designer experience to obtain good performance. The method presented here allows the automatic generation of valves similar to the Tesla one, obtained automatically by a topology optimization algorithm. It is the first time that a three dimensional method is presented, the available algorithms in the open literature works in two dimensions. A fluid sedimentation process enables the creation of a new geometry optimized to meet a prescribed set of performance, such as pressure losses. The steepest descent method is used to approximate the integrals met during the calculation process. The optimizer is used to obtain three dimensional geometries for different multi-objective functions. The geometry is compared to an existing similar solution proposed in the open literature and validated. The results are compared to a Tesla valve to show the performance of the optimized geometries. The advantage of the proposed solution is the possibility to apply the design method with any spatial constraints and for a wide range of mass flow.

Mechanical Properties of Ti-6Al-4V Fabricated by Electron Beam Melting

2016 ◽  
Vol 704 ◽  
pp. 235-240 ◽  
Author(s):  
Alexander Kirchner ◽  
Burghardt Klöden ◽  
Thomas Weißgärber ◽  
Bernd Kieback ◽  
Achim Schoberth ◽  
...  
Keyword(s):  
Electron Beam ◽  
Additive Manufacturing ◽  
Electron Beam Melting ◽  
Lead Time ◽  
Fatigue Testing ◽  
Heat Treatments ◽  
Complex Geometries ◽  
Powder Bed ◽  
Near Net Shape ◽  
High Degree

Powder bed additive manufacturing of titanium components offers several advantages. The high freedom of design enables the fabrication of structurally optimized, lightweight parts. Complex geometries may serve additional functions. The use of additive manufacturing has the potential to revolutionize logistics by dramatically reducing lead time and enabling a high degree of customization. Manufacturing near net shape parts reduces the loss of expensive material.For the application in safety relevant parts certainty about static and fatigue strength is critical. A challenge arises from complex influences of built parameters, heat treatments and surface quality. Ti-6Al-4V specimen built by electron beam melting (EBM) were subjected to heat treatments adapted to various employment scenarios. The results of tensile and fatigue testing as well as crack propagation and fractography will be compared to titanium manufactured conventionally and by selective laser melting (SLM). The mechanical behavior will be correlated to the microstructural evolution caused by the heat treatments

scholarly journals A Novel Additive Manufacturing Method of Cellulose Gel

Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 6988
Author(s):  
Hossein Najaf Zadeh ◽  
Daniel Bowles ◽  
Tim Huber ◽  
Don Clucas
Keyword(s):  
Additive Manufacturing ◽  
Three Dimensional ◽  
Material Design ◽  
Potential Method ◽  
Support Material ◽  
Gel Structure ◽  
Manufacturing Method ◽  
Wide Range ◽  
Need For Support ◽  
Cellulose Gel

Screen-additive manufacturing (SAM) is a potential method for producing small intricate parts without waste generation, offering minimal production cost. A wide range of materials, including gels, can be shaped using this method. A gel material is composed of a three-dimensional cross-linked polymer or colloidal network immersed in a fluid, known as hydrogel when its main constituent fluid is water. Hydrogels are capable of absorbing and retaining large amounts of water. Cellulose gel is among the materials that can form hydrogels and, as shown in this work, has the required properties to be directly SAM, including shear thinning and formation of post-shearing gel structure. In this study, we present the developed method of SAM for the fabrication of complex-shaped cellulose gel and examine whether successive printing layers can be completed without delamination. In addition, we evaluated cellulose SAM without the need for support material. Design of Experiments (DoE) was applied to optimize the SAM settings for printing the novel cellulose-based gel structure. The optimum print settings were then used to print a periodic structure with micro features and without the need for support material.

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