Temperature Distribution In Wire Research Articles

The use of potential drop measurements to predict the temperature distribution in a thin wire with current flowing through it

When a current is supplied to a thin wire having smaller heat capacity, the temperature of the wire easily increases due to the principle of Joule heating. The temperature distribution in the wire has constituted an important issue for thin wire application. This paper reports a method to predict the temperature distribution in a thin wire through which current is flowing. The potential drops at the surfaces of thin Cu wires with diameters of 25 µm and 100 µm were measured. For these measurements the points of contact were close together, enabling us to measure the temperature dependency of the electrical resistivity of the wire. On the other hand, potential drop measured between the points of contact much further apart provided the information on the temperature distribution in the wire. By assuming the symmetric and parabolic temperature distribution, the temperature distributions in the Cu wires of 25 µm and 100 µm thick were predicted using the potential drop measurements made with the points of contact much further apart. The temperature distributions predicted were in good agreement with those measured by infrared thermography. The validity of the proposed method was also verified by conducting a similar experiment on Fe wire having a diameter of 100 µm.

A finite element analysis of effects of ultrasonic welding parameters on the temperature distribution in wire bonding

AbstractWire bonding is an essential process in the automotive industry. Multi‐strand flexible aluminium cables are used for connection of different electronic components and electrical centres in cars. As an alternative for crimping technology in wire bonding, ultrasonic welding (USW) is applied, which is a rapid manufacturing process used to create solid joints between mating materials at low energy consumption compared to the known welding processes, such as oxy‐fuel welding and arc welding. An ultrasonic welding machine consists of different parts, such as pneumatic cylinder, piezoelectric converter, booster, welding sonotrode and anvil. Despite of the simplicity of the USW process, choosing the right machine and process parameters, like pressure of the pneumatic cylinder, welding time as well as vibration amplitude of the piezo‐converter, is a tricky and complicated task for obtaining an adequate bond. Experimental investigations done in this area are extremely time‐consuming and require a lot of effort. Therefore, some new approaches must be developed to understand the process in more detail. The present study focuses on the influence of the ultrasonic welding parameters, such as sonotrode pressure and vibration amplitude, on the temperature distribution at interfaces of two mating pieces in wire bonding [1,2]. Investigations are done by means of FEM simulations as well as by experiments. The results are then extended to thermo‐mechanical analysis of multi‐strand models. (© 2016 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Numerical Investigation on the Effects of Sample Wire Motion in a Tube Furnace

A tube furnace is a heat treatment device in which a specimen is heated in the presence of an inert gas using electric heating coils embedded in a thermally insulating matrix. Heat flux and temperature gradients of sample during heat treatment in a tube furnace depend on the gas and wire velocities. These parameters were used in this paper for a 2-D axisymmetric numerical study to determine an optimized relationship between the temperature and the sample wire motion. The results show that wire velocity considerably affected the wire temperature distribution and increased the gas temperature to some extent. The phenomenon resulted in the shifting of the heating zone on the wire surface and occurrence of an inner convection heat transfer.

Bead formation and wire temperature distribution during ULTRA-HIGH-SPEED GTA WELDING using pulse-heated hot-wire

The purpose of this study was to investigate the melting phenomenon of filler wire in detail and to obtain the precise temperature distribution of filler wire during GTA welding under the ultra-high welding speed condition in order to develop the ultra-high-speed GTA welding process with the pulse-heated hot-wire system by using three kinds of materials. The melting phenomenon of filler wire was observed using a high-speed camera and the temperature distribution of filler wire was measured using a radiation thermometer. From the above result, the adequate welding conditions of each material to make the GTA welding process with the ultra-high welding speed could be obtained. The ultra-high-speed GTA welding process needed the adequate wire current in order to obtain the adequate temperature distribution and the adequate melting position of filler wire. Moreover, the temperature distributions of three kinds of filler wire could be estimated by using the proposed simple estimation method.

저압 배선선로의 과전류 사고시 전기화재분석에 관한 연구

최근 전자계-열계 해석 소프트웨어의 발전에 힘입어 전자계-열계 해석 이론을 바탕으로 컴퓨터 시뮬레이션에 의한 전기화재의 정확한 원인분석과 조사가 체계적으로 연구되고 있으나, 매우 미흡한 실정이다. 따라서 본 논문에서는 비닐 평형 코드(600 V, VFF, 2C×1.25㎟)을 모델로 하여 과전류시 전류크기에 따른 전선의 온도분포 및 이격거리에 따른 도체 상호간의 힘을 컴퓨터 시뮬레이션(Flux2D)을 통하여 계산하며, 또한 직접 제작한 대전류 공급장치(형명 : EHT_EFAD, Korea)를 사용하여 과전류시 전류크기와 공급시간에 따른 도체 상호간의 이격거리에 대하여 실험함으로써 과전류로 인한 전기화재 원인분석 방법에 대하여 제안하고자 한다.

ワイヤ放電加工のワイヤ温度分布計測の試み 第２報 加工中のワイヤ平均温度

To prevent the wire breakage during Wire EDM there should be information of the wire temperature because it is said that the wire may be broken by increasing of wire temperature. In our previous report we tried to measure the wire temperature distribution from discharging currents and voltage between the upper and the lower contactors contacting to the wire and averaged wire temperatures of 100°C or less were obtained. But these data were not calibrated and were not precise enough.In this report we retry to obtain precise averaged wire temperatures for two types of power supplying methods. In the first method the power is supplied from the lower contactor and in the 2nd the power is supplied simultaneously from the upper and the lower contactors. Also two types of workpiece materials, SUS304 and SKD11 are machined and results are compared. Wire temperatures are calibrated. It was found that during Wire EDM the wire resistance facing to the workpiece is greater than the static value and especially great in the case of ferromagnetic workpiece. Obtained averaged wire temperatures were almost 100°C at the maximum cutting speed for any cases.

ワイヤ放電加工のワイヤ温度分布計測の試み

A maximum cutting speed of WIRE EDM is restricted by a wire rupture during WIRE EDM. Normally it is said that too high machining speed supplies high temperature on the wire and causes the wire breaking. But it was difficult to measure the wire temperature during EDM because the wire is moving and surrounded by a workpiece material. Only a mathematical analysis is tried to obtain a temperature distribution assuming a heat transfer coefficient, but not considering a effect of water flow.We already found that a discharge concentration occurs just before the wire breaking. Then the discharge concentration may be the main reason of the wire rupture. In this case a local wire temperature may increases so high but not a averaging wire temperature. But it depends on machines. If an ON/OFF control in power supply was so fine as to avoid the discharge concentration, the averaging wire temperature may be already so high, and the prevention of discharge concentration may be a fruitless effort for the machining speed. Then it is important to know the real wire temperature to develop the machining speed on WIRE EDM.In this report we describe an attempt to measure the wire temperature distribution from discharging currents and voltages during WIRE EDM. Results show that the averaging wire temperature may be 100°C or less.

Natural Convection Cooling of an Electrical Conductor Wire

The conductor wire connected to an electrical device generates and dissipates heat. For the successful design of the device, therefore, it is essential to analyze thermal response of the conductor wire in conjunction with the device. In this study, an approximate analytical method for the steady state wire temperature distribution is presented. Also, a finite difference solution for the transient behavior is given. For the steady state solution the conductor wire alone can be analyzed in a decoupled manner, but not for the transient case. The agreement between the steady solution and the transient solution at t=?is excellent.

An approximate method for predicting temperature distribution in wire wrapped fuel assemblies of a liquid metal fast breeder reactor

An approximate method for predicting temperature distribution in wire wrapped fuel assemblies of a liquid metal fast breeder reactor