#MAKING AN INDUCTION COIL TRIAL#

It is a reliable and rapid technique, ranging from fractions of a second for small parts to 30вЂ“60 seconds for parts with long (400 cm) bond lines, and results in structural, hermetic, or high-pressure welds. The heat released is used to melt and fuse thermoplastics, to heat hot-melt adhesives, or to provide rapid adhesive cures for thermosets. Induction welding uses induction heating from high radio-frequency alternating current to magnetically excite ferromagnetic particles embedded in a bonding agent (with a thermoplastic or adhesive matrix) placed at the joint interface of the two parts being welded. Sina Ebnesajjad, in Melt Processible Fluoroplastics, 2003 14.4.1.9 Induction Welding Overall, induction heating methods offer no advantage over joule heating, save the ability to use rectangular, disk or cylindrical specimens, rather than wire, ribbon or foil samples. Thermocouples will suscept in the RF heating field and thus temperature measurement and control depends on pyrometry, similarly to the joule heating approach. Induction heating provides more freedom in the design of samples, but still requires that temperature cycling rate depends on the sample heat capacity and again control and measurement of sample temperatures is difficult. For non-conducting materials or samples of complex shape, a secondary susceptor can be used, but its heat capacity can limit heating and cooling rates that can be achieved. Like joule heating, induction heating is also limited to electrically conducting samples if rapid heating and cooling cycles are to be achieved. HOJDA, in Novel Approaches to Improving High Temperature Corrosion Resistance, 2008 20.2.2 Induction heating The input currents were set to reach the desired level of surface temperature during the preheated machining experiment. Those equations were then utilized to set the current value for a particular heating temperature. By using the regression method, characteristic equations of current as a function of temperature were developed at the 95% confidence interval. The results of temperature control experiments for the feed are developed in heat-assisted machining. Thus, for a particular current and feed value, the surface temperature was determined.

#MAKING AN INDUCTION COIL TRIAL#

The same trial was repeated two to three times for every experiment, and the average temperature was considered. The surface temperature reading was taken, when the coil just passed the sensing rod of the thermocouple. The workpiece was then passed with a specific feed rate, so that the sensing rod of thermocouple remained just below the coil. The input current was set to a particular value to produce a desired level of heating temperature on the workpiece surface. The sensing rod of a thermocouple was attached to the workpiece surface. The distance between the coil and workpiece was kept constant at 5В mm and was also maintained throughout all the experimental work. Thesis, Manufacturing and Materials Engineering Department, IIUM, Malaysia, 2009. Improvement of Machinability of Titanium Alloy Ti-6Al-4V through Workpiece Preheating. Experimental setup for determining the currentвЂ“temperatureвЂ“feed relationships. The magnetic flux concentrator must be positioned between the legs of the hairpin inductor to improve heating efficiency and reduce coil current.ДЇigure 22. Hairpin-type inductors are usually bent or brazed copper tubing and resemblance of the inductor's loop shape to a lady's hairpin. If the workpiece has an ID less than 20 mm, then hairpin inductors are sometimes used, requiring part rotation ( Figure 25, middle-right). Since the return leg of the inductor usually goes through the center of the coil, the smallest outside diameter (OD) of solenoid-type inside diameter (ID) coils is usually limited to about 12 mm, but 19 mm is more typical. In some cases, the head of the internal inductor is machined from a solid copper bar ( Figure 25, bottom photos) providing a rigid and robust structure and minimizing the end effect of coil helix. Internal coils are typically made of copper tubing that is spiral wrapped the same way a solenoid is wrapped. Single-turn and multiturn solenoids are often used for heating internal surfaces. Inductors for hardening internal surfaces.

Making an induction coil