Tip to Side Welding of Ultrathin Pt Wires by Joule Heating

Mechanical Engineering Journal

Yamaguchi

2019

Self Cite

This paper treats the Joule heat welding of thin Pt wires having various diameters. Joining of fine-scale materials, such as micro-or nanowires, has been essential to create advanced materials systems. Joule heat welding is one of the suitable way for this purpose. It has been reported that thin wires were welded together under the supply of constant direct current, and the welding condition was sensitive to the thermal boundary conditions around the wires under the current supply, which was affected by the heat transfer from the wire surface to the ambient and the heat conduction at the ends for the current supply. The diameters of thin Pt wires were 0.8-20 m, and the current required to cut the wire by Joule heating was investigated. The temperature of the wire having the smaller diameter was easily increased by Joule heating, and this became remarkable with increasing the slenderness ratio, i.e., the ratio of the diameter to the length for current supply. An index related to the temperature of the wire under the current supply was introduced to describe the thermal boundary conditions around the wire. The behavior of the index against the diameter was approximated by the exponential functions, and the thermal boundary conditions around the wires having various diameters became predictable. Finally, the validity of the thermal boundary conditions determined and predicted in this study was verified by conducting the experiments to cut and weld the wires by Joule heating.

Section: Introductionmentioning

confidence: 99%

Thermal boundary conditions around thin Pt wires under the current supply and its application for Joule heat welding of wires having various diameters

Mechanical Engineering Journal

Yamaguchi

2019

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“…Welding the tips of two thin wires together is classified as one-dimensional welding from the point of view of current flow. Moreover, the tip of a thin wire has been successfully welded to the side of a second wire and this is classified as two-dimensional welding (Fukui and Tohmyoh, 2011). To widen the applications, this welding technique can be extended further.…”

Section: Introductionmentioning

confidence: 99%

Joule heat welding of thin wires to thin films

Mechanical Engineering Journal

Fujimori

2014

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To effectively use micro or nano materials and create advanced materials systems from them, welding techniques for such small scale materials are vital. For this purpose, the tips of two thin wires were welded together with Joule heat and the conditions required to achieve it was discovered experimentally. In this paper, the Joule heat welding of thin wires to thin films deposited on substrates is described. To derive the conditions required to achieve this, a heat conduction model for a cylindrical element in the film located at the contact between the wire and the film is considered and the critical thickness of the film above which the welding conditions are independent of film thickness is derived analytically. The validity of the heat conduction model was experimentally verified by welding 0.8 m diameter Pt wires onto thin Pt films on electrically-insulated substrates. The experiments are performed for various combinations of the length of the wire and the thickness of the films. The current required for welding the wires onto the films having the thickness over the critical thickness are investigated and the conditions required for the welding are found to be coincident with those for welding the tips of two wires with Joule heat.

“…30) Moreover it was also found that there was little structural damage around the welds. 31) We also succeeded in carrying out tip-to-side welding, 32) and in many low dimensional material applications, not only wire to wire (line to line) welding, but also wire to substrate (line to plane) welding is required.…”

Section: Introductionmentioning

confidence: 99%

Welding Thin Pt Wires with Dissimilar Diameters by Joule Heating

Fujimori

2013

Jpn. J. Appl. Phys.

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In this paper, the Joule heat welding of thin Pt wires with different diameters was performed and the current required for successful welding was investigated. The diameter of one wire was 800 nm and the others had various diameters of 1, 2, and 5 µm. Various combinations of wire lengths were used in the welding experiments. The minimum and maximum currents for successful welding were found to be highly dependent on the length of the 800 nm diameter wire. From these experimental results, it was inferred that the highest temperature in the system during welding occurred in some part of the 800 nm diameter wire and that the temperature in the larger diameter wire with sufficient heat capacity were almost unchanged. It was also found that the conditions for successfully welding wires of different diameter can be described by a parameter previously proposed for classifying the successful conditions for welding two 800 nm diameter wires.