Micro laser metal wire deposition for additive manufacturing of thin-walled structures

2018 ◽  
Vol 100 ◽  
pp. 9-17 ◽  
Author(s):  
Ali Gökhan Demir
Author(s):  
S Mantovani ◽  
GA Campo ◽  
M Giacalone

Structural engineering in the automotive industry has moved towards weight reduction and passive safety whilst maintaining a good structural performance. The development of Additive Manufacturing (AM) technologies has boosted design freedom, leading to a wide range of geometries and integrating functionally-graded lattice structures. This paper presents three AM-oriented numerical optimization methods, aimed at optimizing components made of: i) bulk material, ii) a combination of bulk material and graded lattice structures; iii) an integration of solid, lattice and thin-walled structures. The optimization methods were validated by considering the steering column support of a mid-rear engine sports car, involving complex loading conditions and shape. The results of the three methods are compared, and the advantages and disadvantages of the solutions are discussed. The integration between solid, lattice thin-walled structures produced the best results, with a mass reduction of 49.7% with respect to the existing component.


Author(s):  
Arackal Narayanan Jinoop ◽  
Christ Prakash Paul ◽  
Kushvinder Singh Bindra

Laser Additive Manufacturing (LAM) is one of the greener routes for fabrication of Inconel 718 (IN718) components. In the present work, Taguchi L9 array based optimization is performed using grey relational analysis to optimize the process parameters for the fabrication of thin walled structures using a 2 kW fibre laser based additive manufacturing system. Within the framework of the experimental conditions of the study, the LAM processing parameters, i.e., laser power, scan speed and powder feed rate, are optimized for minimum width and maximum height. The optimized parameters are used for the deposition of multi-layered walls and it is subjected to heat treatment at 1000 °C for duration of one-hour, followed by water quenching. Comprehensive investigations on microstructural and mechanical behaviour using optical microscopy (OM), X-ray diffraction (XRD) analysis, micro-hardness and automated ball indentation (ABI) are carried out. Microstructure examinations of LAM deposits of IN718 reveal intermixed dendritic and cellular structures. However, homogenization in microstructure is observed through heat treatment resulting in reduced micro-hardness. It is also observed that there is considerable increase in the crystallite size of the deposits after heat treatment. This study opens a new route for fabrication of thin walled structures using LAM with modified properties by erasing the thermal history through heat treatment.


Coatings ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1141
Author(s):  
Leandro João da Silva ◽  
Henrique Nardon Ferraresi ◽  
Douglas Bezerra Araújo ◽  
Ruham Pablo Reis ◽  
Américo Scotti

The present paper aimed at assessing the effect of two thermal management approaches on geometry and productivity of thin-walled structures built by Wire + Arc Additive Manufacturing (WAAM). Thin-walls of ER 5356 (Al5Mg) with different lengths and the same number of layers were deposited via the gas metal arc (GMA) process with the aid of an active cooling technique (near-immersion active cooling—NIAC) under a fixed set of deposition parameters. Then, the same experiment was performed with natural cooling (NC) in air. To characterize the thermal management approaches, the interpass temperature (i.e., the temperature at which subsequent layers are deposited) were monitored by a trailing/leading infrared pyrometer during the deposition time. Finally, thin walls with a fixed length were deposited using the NC and NIAC approaches with equivalent interpass temperatures. As expected, the shorter the wall length the more intense the deposition concentration, heat accumulation, and, thus, geometric deviation. This behavior was more evident and premature for the NC strategy due to its lower heat sinking effectiveness. The main finding was that, regardless of the thermal management technique applied, if the same interpass temperature is selected and maintained, the geometry of the part being built tends to be stable and very similar. However, the total deposition time is somewhat shorter with the NIAC technique due its greater heat sinking advantage. Thus, the NIAC technique facilitates the non-stop manufacturing of small parts and details via WAAM.


Author(s):  
Abdullah T. Alsharhan ◽  
Timotei Centea ◽  
Satyandra K. Gupta

Traditional extrusion based additive manufacturing (AM) processes build parts by depositing material in planar layers. The development of processes that adopt a non-planar approach is becoming a subject of significant interest in AM research. It is expected that such processes will impart superior mechanical strength to anisotropic and thin-walled structures, and will especially be useful in exploiting continuous fiber reinforced composites in additive manufacturing. This paper presents an extrusion based non-planar additive manufacturing process. The process allows for the deposition of material along 3-dimensional paths, providing the capability to reorient deposition head, build objects on curved platforms, and create complete structures using one continuous strand. Two different parts are fabricated and tested in this paper. One is produced using the developed process, while the other is created using a commercial FDM 3D printer. The two specimens are then mechanically tested to examine their behavior in two different loading configurations, and to investigate the effect that the deposition method and orientation has on the failure mode.


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