scholarly journals Thermal, Viscoelastic and Surface Properties of Oxidized Field’s Metal for Additive Microfabrication

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7392
Author(s):  
Rosendo Zamora ◽  
Juan Martínez-Pastor ◽  
Félix Faura

Field’s metal, a low-melting-point eutectic alloy composed of 51% In, 32.5 Bi% and 16.5% Sn by weight and with a melting temperature of 333 K, is widely used as liquid metal coolant in advanced nuclear reactors and in electro–magneto–hydrodynamic two-phase flow loops. However, its rheological and wetting properties in liquid state make this metal suitable for the formation of droplets and other structures for application in microfabrication. As with other low-melting-point metal alloys, in the presence of air, Field’s metal has an oxide film on its surface, which provides a degree of malleability and stability. In this paper, the viscoelastic properties of Field’s metal oxide skin were studied in a parallel-plate rheometer, while surface tension and solidification and contact angles were determined using drop shape analysis techniques.

2016 ◽  
Vol 23 (3) ◽  
pp. 379-382
Author(s):  
O. N. Kashinsky ◽  
P. D. Lobanov ◽  
A. S. Kurdyumov ◽  
N. A. Pribaturin

Author(s):  
Jing Liu ◽  
Yue-Guang Deng ◽  
Zhong-Shan Deng

Efficient cooling of a high performance computer chip has been an extremely important however becoming more and more tough issue. The recently invented liquid metal cooling method is expected to pave the way for high flux heat dissipation which is hard to tackle otherwise by many existing conventional cooling strategies. However, as a new thermal management method, its application also raised quite a few challenging fundamental and practical issues for solving. To illustrate the development of the new technology, this talk is dedicated to present an overview on the latest advancements made in the author’s lab in developing the new generation chip cooling device based on the liquid metal coolant with melting point around room temperature. The designing and optimization of the cooling device and component will be discussed. Several major barriers to prevent the new method from practical application such as erosion between liquid metal coolant and its substrate material will be outlined with good solutions clarified. Performance comparison between the new chip cooling method with commercially available products with highest quality such as air cooling, water cooling and heat pipe cooling devices were evaluated. Typical examples of using liquid metal cooling for the thermal management of a real PC or even super computer will be demonstrated. Further, miniaturizations on the prototype device by extending it as a MEMS cooling device or mini/micro channel liquid metal cooling device will also be explained. Along with the development of the hardware, some fundamental heat transfer issues in characterizing the liquid metal cooling device will be discussed through numerical or analytical model. Future challenging issues in pushing the new technology into large scale practices will be raised. From all the outputs obtained so far, it can be clearly seen that the new cooling strategy will find very promising and significant applications in a wide variety of engineering situations whenever thermal managements or heat transport are needed.


Geofluids ◽  
2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Yunfeng Dai ◽  
Zhifang Zhou ◽  
Jin Lin ◽  
Jiangbo Han

To describe accurately the flow characteristic of fracture scale displacements of immiscible fluids, an incompressible two-phase (crude oil and water) flow model incorporating interfacial forces and nonzero contact angles is developed. The roughness of the two-dimensional synthetic rough-walled fractures is controlled with different fractal dimension parameters. Described by the Navier–Stokes equations, the moving interface between crude oil and water is tracked using level set method. The method accounts for differences in densities and viscosities of crude oil and water and includes the effect of interfacial force. The wettability of the rough fracture wall is taken into account by defining the contact angle and slip length. The curve of the invasion pressure-water volume fraction is generated by modeling two-phase flow during a sudden drainage. The volume fraction of water restricted in the rough-walled fracture is calculated by integrating the water volume and dividing by the total cavity volume of the fracture while the two-phase flow is quasistatic. The effect of invasion pressure of crude oil, roughness of fracture wall, and wettability of the wall on two-phase flow in rough-walled fracture is evaluated.


Author(s):  
Y. Y. Yan

A micro/meso scale modelling of two-phase droplets move on hydrophilic/hydrophobic surfaces with micro roughness is reported. The physical model is basically of two-phase flow interacting with the surfaces of different hydrophobicity or wettability. Numerical modelling based on the lattice Boltzmann method (LBM) is developed and applied to the computational calculation and simulation. The LBM modelling deals with surface tension dominated behaviour of water droplets in air spreading on a hydrophilic surface with hydrophobic strips of different sizes and contact angles under different physical and interfacial conditions, and aims to find quantitative data and physical conditions of the biomimetic approaches. The current LBM can be applied to simulate two-phase fluids with large density ratio (up to 1000), and meanwhile deal with interactions between a fluid-fluid interface and a partial wetting wall. In the simulation, the interactions between the fluid-fluid interface and the partial wetting wall with different hydrophobic strips such as single strip, intersecting stripes, and alternating & parallel stripes, of different sizes and contact angles are considered and tested numerically; the phenomena of droplets spreading and breaking up, and the effect of hydrophobic strips on the surface wettability or self-cleaning characteristics are simulated, reported and discussed.


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