I caught a university in Australia over 700kms away sending a block of stone with aluminium mixed in it to a laser and water jet cutter next to a Naval base. Granite amplifies.
Excellent video, fascinating.. thank you for the knowledge, although truthfully I cannot say how much be will be retained.. lol.. thanks again.. Thom in Scotland.
Great, informative video! It would be nice, if you could try ferritic (ferromagnetic) vs. austenitic (paramagnetic) steel in the induction coil and see how they heat up. Keep up the amazing work!
there are a lot of things I wasn't understand about induction melting now I understand them , thank you . but there are some things I can't understand in this video & really can't find any answer after hard search on google : 1 - it is known than that lower frequency means higher current penetration which should means that 8.5 KHz frequency should be more effective than 17 KHz , then why lower frequency can't able to heat smaller pieces ? is higher penetration means lower efficiency of heating smaller parts ? as I remember the lower frequency used the more homogenized molten metal & industrially very low frequency of 60 Hz is used to melt steels using induction melting method . 2 - in levitation melting experiments , I understand that there is a limit of size of metal piece to be completely levitated in molten state . but what the actual factors control this size limit ? does simply increasing power or frequency increasing this size limit ? or it mainly depending on the design of induction coils ? does it differs by the metal to be melted ? 3 - can metals with very high melting points like tungsten melted using levitation method ? or there is a limits ? 4 - can temperature of a metal heated by induction be fixed ? and how to fix it ? if for example I want to heat a large steel part quickly to 1000°C and hold at this temperature for hours , is that even possible ? 5 - how to increase temperature of the molten metal ? power or frequency ? & is it possible to rise temperature to near that boiling point of a metal "i.e. 2800°C for steel" ?
1 ) You are right about this: "lower frequency means higher current penetration" however it is not the only effect. If we increase frequency ( and keep other parameters fixed), induced currents in the metal rise proportionally to frequency. You can see that easily when you look equations for induced current ( I also did in the previous video). The skin - effect is a secondary effect and in this case, it is parasitic ( decreases the total power that dissipates in the workpiece). 2) Firstly, you need enough power to levitate something which is usually, it is measured in kW. Secondly, the metal you want to levitate has to be a good electrical conductor and preferably low density. Otherwise, you would need to increase current even more but even that has limits ( like how much heat you can remove with water cooling in copper pipes). Thirdly, for this configuration regardless of current strength or frequency, at the center of the axis, there is no net force pointing upwards. This becomes a problem with molten metal since in center point it is held to the larger piece only by surface tension forces. This limits funnel-shaped coils to about 100 grams of aluminum before it starts leaking out. For different metals, this would vary and depend on surface tension and viscosity. And lastly, in larger sizes, the flow in the molten metal becomes important since it dictates shape and stability. 3) There is no upper limit of temperature. There are problems like electrical conductivity decrease with temperature increase for all metals. Also, radiating heat losses rise with temperature in 4th power so you would definitely need heat shields. I know germans who have melted ZrO2 at around 3000 C by induction heating. ( it was semi levitating though) 4) Possible, but not straightforward. You heat it up to 1000 C and manually lower power to find equilibrium ( which would differ every time if you don't heat identical pieces). A smarter method would be a feedback loop from the thermocouple or thermal camera to the brains of the inductor which adjusts power in real-time. 5) For every size and metal there exist optimal frequency at which to heat it. If you are close to your frequency all you can do is raise the current.
Do you think it would be possible to layer the induction fields like an electromagnet? Where the layers magnify the magnetic forces. Also maybe you could make the coil out of spinning mercury vapor. Or maybe even a plasma. :)
If you put the coil in a vacuum chamber you might be able to use it to forge a diamagnetic ferrous material. Heat it up burn off all oxygen and create vacuum. Turn off and drop material in cast and let cool slowly in the absence of oxygen. Might work. :)
كيف يمكن صنع مثل هاذه الالة اذا كان لديك معلومات ارجو ان تساعدني الموجود على اليوتيوب لا يصل الا الحرارة المطلوبة اريد صهر الفولاذ والحديد اريد الوصول الى ١٠٠٠ درجة وشكرا
Forces are proportional to electrical conductivity of material all trough out frequency range because it is easier to induce current in good conductor. Forces are also proportional to frequency up until skin effect sets in. However, in all levitation setups high frequencies are already used and skin effect is present, meaning frequency change will affect each process differently on case by case basis. It is complicated to predict effects qualitatively since multiple effect opposing effects overlay at high frequencies.
Interesting question. I reckon applying sound through the air wouldn't be terribly effective, but mayhaps you could apply vibration using a rod directly to the material. In that case I think you could find the resonant frequency of the liquid metal. You'd definitely see something interesting.
The copper coil has a hollow core for the coolant to flow. The cross-section is about 10x10 mm, but I don't know the wall thickness hence the empty core size. To melt steel you would need more heat insulation. Or at least crucible with a closed top. Otherwise, heat losses would permit you to melt steel.
So I was thinking about the core of the earth, I am looking for someone to try an experiment where they have a magnetic ball inside of an oppositely charged magnetic ball to recreate essentially the core of the earth. I happened upon these experiments.. and judging from what I'm seeing one of the balls would melt but continue spinning just as scientists theorize about our core.. Now if this is the case... that would mean that the ball would create its own magnetic field since it is 2 metals flowing against each other. if we were to create a miniature core, would we be able to use it as an energy source? If someone knows about an experiment similar to what I'm talking about, can you point me in that direction? I can't seem to find anything like what I am talking about
Because of the relatively low melting temperature and surface properties of aluminum. The emissivity of aluminum is 0.03 which is a very low value ( max for a ideal black body is 1.00). Coupled with a melting temperature of 660 C you have a 100 to 200 C window above melting temperature where aluminum is liquid but not visibly glowing.
Electroboom has an entire website, along with his youtube videos that can explain what's going on here. Physics books typically have an electromagnetism section and you could probably find some good books specifically about the physics of induction heating... but tbh this channel is pretty good too. The reason it levitates is similar to the reason you can create an electromagnet with insulated wire wrapped around an iron core.
Practically no. Unless the rock was mostly metal parts (that are connected to eachother!) current would not flow in it. There would be only small currents in the inclusion of metal but melting or levitating the rock would be close to impossible with reasonable currents.
It is a balance of multiple effects. Heating (dissipated power) is proportional to volume. Cooling by conduction, convection, and radiative losses are all proportional to the surface. So smaller objects have higher surface/volume balance hence lower temperature if induced power density is the same (in reality it is not the same). To complicate things heating does not scale with the size and there are differences how bigger and smaller objects heat up for any given frequency. That can be analyzed by looking at dimensions of the workpiece and calculated skin depth for that frequency.
Nothing that can be felt or leaves any noticeable effect on extremities or body. ( Disclaimer: I'm not sure about the long-term effects on the brain if you stuck your whole head in an inductor. They are more sensitive to a magnetic and electric field than extremities. Haven't looked into it.)
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