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Powder-Based Additive Manufacturing Systems
Published in G.K. Awari, C.S. Thorat, Vishwjeet Ambade, D.P. Kothari, Additive Manufacturing and 3D Printing Technology, 2021
G.K. Awari, C.S. Thorat, Vishwjeet Ambade, D.P. Kothari
LENS systems are used for the repair and rapid manufacturing of metal parts in state-of-the-art materials such as titanium and stainless steel. The LENS MR-7 system can be used to quickly create materials of extremely high quality. The LENS MR-7 system offers a working envelope of 300 mm cubed, making it ideal for the manufacture or maintenance of smaller parts. LENS systems use high-power fiber laser energy to create structures directly from metal powders, alloys, ceramics, or composites, one layer at a time. Both powder feeders allow for the processing of gradient materials—each layer may have a different chemistry. This allows for the development and study of new materials at incredible pace. LENS systems are used for applications ranging from rapid alloy growth and practical prototyping to rapid manufacturing or repair over the entire product lifecycle (Figure 5.4).
Optimization of Laser-Based Additive Manufacturing
Published in Linkan Bian, Nima Shamsaei, John M. Usher, Laser-Based Additive Manufacturing of Metal Parts, 2017
Amir M. Aboutaleb, Linkan Bian
LENS is an AM process that can build complex, functional parts in metal, by slicing 3D objects into 2D layers of user-defined thickness and superimposing successive layers. Users must choose the layer thickness and match it with the deposition to keep the laser in focus throughout the build. If a mismatch exists between the layer thickness and the deposited thickness, the laser is no longer focused on the melt-pool surface, leading to geometric inaccuracy of parts, or even failures of build. The deposition thickness is typically governed by other process parameters, such as laser power, laser velocity, hatching spacing, and powder mass flow rate. To match the layer thickness with deposition, it is very important to understand and estimate the relationship between these process parameters and the deposition thickness so that the layer thickness can be optimized based on the chosen process parameters.
3D Nanoprinting in the Aero-Industries
Published in Ajit Behera, Tuan Anh Nguyen, Ram K. Gupta, Smart 3D Nanoprinting, 2023
Alperen Doğru, M. Batıkan Kandemir, M. Özgür Seydibeyoğlu
A high-power laser beam injects molten metal powder into a precise location in this process. The material solidifies by spontaneous cooling. A closed environment containing argon gas is used to prevent oxidation during the process. The demonstration of the method is in Figure 2.8. Stainless steel, nickel-based alloys, Tİ6AL4V, tool steels, copper alloys, and alumina are materials suitable for the LENS method. This process is used in the repair of difficult and expensive parts due to its high precision. However, for sensitive applications such as turbine blade repair, attention should be paid to the formation of residual stress caused by uneven heating and cooling, which adversely affects the mechanical properties [21].
In search for classification and selection of spare parts suitable for additive manufacturing: a literature review
Published in International Journal of Production Research, 2020
Casper Selmer Frandsen, Martin Mathias Nielsen, Atanu Chaudhuri, Jayanth Jayaram, Kannan Govindan
Laser engineered net shaping (LENS): Direct Energy Deposition is a process in which focused thermal energy is sued to fuse materials by melting as they are deposited. LENS, one of the technologies following the above process builds objects by focusing a high-powered laser beam on top of a substrate, whereby a molten pool is created, in which metal powder is injected to build layers. The supporting foundation beneath the laser beam is moved down as each layer is build, by which the desired geometry is created. LENS offers appropriate control of manufacturing parameters, and desirable geometric and material properties. Apart from being used to manufacture new parts, it can also be used to repair parts. Drawbacks of this technology are that parts that are produced with LENS technology require postproduction, as they must be cut from the build substrate, and have rough surfaces.
In-situ monitoring of melt pool images for porosity prediction in directed energy deposition processes
Published in IISE Transactions, 2019
Mojtaba Khanzadeh, Sudipta Chowdhury, Mark A. Tschopp, Haley R. Doude, Mohammad Marufuzzaman, Linkan Bian
We focus on modeling the thermal image data streams obtained during the fabrication of parts using a Laser Engineering Net Shaping (LENS) system. LENS is a means to build metallic prototypes/parts by combining the material and energy delivery for simultaneous deposition and part forming. LENS does not rely on a pre-deposited layer of metallic powder and thus may be used as a means to repair or coat parts via cladding. In addition, due to the combined material/energy delivery method, LENS can be readily utilized to create functional graded/composed parts with varying material/alloy concentrations. Finally, preform mixing such as coaxial powder delivery can be accomplished with LENS (Thompson et al., 2015).