scholarly journals In-line evanescent-field-coupled THz bandpass mux/demux fabricated by additive layer manufacturing technology

OSA Continuum ◽  
2020 ◽  
Vol 3 (9) ◽  
pp. 2407
Author(s):  
A. I. Hernandez-Serrano ◽  
Simon J. Leigh ◽  
Emma Pickwell-MacPherson
Keyword(s):  
Evanescent Field ◽  
Manufacturing Technology ◽  
Additive Layer Manufacturing ◽  
Layer Manufacturing

Topology Optimization, Additive Layer Manufacturing, and Experimental Testing of an Air-Cooled Heat Sink

2015 ◽  
Vol 137 (11) ◽  
Author(s):  
Ercan M. Dede ◽  
Shailesh N. Joshi ◽  
Feng Zhou
Keyword(s):  
Topology Optimization ◽  
Heat Sink ◽  
Computer Aided Design ◽  
Experimental Testing ◽  
Jet Impingement ◽  
Coefficient Of Performance ◽  
Air Cooling ◽  
Additive Layer Manufacturing ◽  
Cloud Data ◽  
Layer Manufacturing

Topology optimization of an air-cooled heat sink considering heat conduction plus side-surface convection is presented. The optimization formulation is explained along with multiple design examples. A postprocessing procedure is described to synthesize manifold or “water-tight” solid model computer-aided design (CAD) geometry from three-dimensional (3D) point-cloud data extracted from the optimization result. Using this process, a heat sink is optimized for confined jet impingement air cooling. A prototype structure is fabricated out of AlSi12 using additive layer manufacturing (ALM). The heat transfer and fluid flow performance of the optimized heat sink are experimentally evaluated, and the results are compared with benchmark plate and pin-fin heat sink geometries that are conventionally machined out of aluminum and copper. In two separate test cases, the experimental results indicate that the optimized ALM heat sink design has a higher coefficient of performance (COP) relative to the benchmark heat sink designs.

Modeling and Prediction of Residual Stresses in Additive Layer Manufacturing by Microplasma Transferred Arc Process Using Finite Element Simulation

2019 ◽  
Vol 141 (6) ◽  
Author(s):  
Sagar H. Nikam ◽  
N. K. Jain
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Temperature Distribution ◽  
Residual Stresses ◽  
Substrate Material ◽  
Tensile Residual Stress ◽  
Additive Layer Manufacturing ◽  
Element Simulation ◽  
Layer Manufacturing ◽  
Transferred Arc

Prediction of residual stresses induced by any additive layer manufacturing process greatly helps in preventing thermal cracking and distortion formed in the substrate and deposition material. This paper presents the development of a model for the prediction of residual stresses using three-dimensional finite element simulation (3D-FES) and their experimental validation in a single-track and double-track deposition of Ti-6Al-4V powder on AISI 4130 substrate by the microplasma transferred arc (µ-PTA) powder deposition process. It involved 3D-FES of the temperature distribution and thermal cycles that were validated experimentally using three K-type thermocouples mounted along the deposition direction. Temperature distribution, thermal cycles, and residual stresses are predicted in terms of the µ-PTA process parameters and temperature-dependent properties of substrate and deposition materials. Influence of a number of deposition tracks on the residual stresses is also studied. Results reveal that (i) tensile residual stress is higher at the bonding between the deposition and substrate and attains a minimum value at the midpoint of a deposition track; (ii) maximum tensile residual stress occurs in the substrate material at its interface with deposition track. This primarily causes distortion and thermal cracks; (iii) maximum compressive residual stress occurs approximately at mid-height of the substrate material; and (iv) deposition of a subsequent track relieves tensile residual stress induced by the previously deposited track.

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