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Ok - so I have googled and this seems like a bad scenario. I have a cast aluminum/magnesium (I think its aluminum/mag alloy... it could be straight magnesium, I am not sure, how can I check?) valve cover that I need to weld some male aluminum -10AN Bosses to. Well... the valve cover puddles nicely, but when we weld... it LOOKS good... but when I tap it with a hammer it... crumbles. So we tried again, and it worked better except I was able to break off the "bead" of the weld. We just give it a try using 4043 rod. I know its most likely the wrong rod... but will this work at all regardless of the rod? The aluminum boss is 6061 I believe.Here is a macro photo of the chunk I was able to pull off with a pair of pliers.The porous side showing was face down - aka, thats the inside of the bead, not the side you'd see. Very porous. The outside of the bead was actually quite nice, though.
Reply:Posting photos @ 800 x 600 allows all your text to be seen.Millermatic 251Spectrum 300 PlasmaEverlast PowerTig 250EXEverlast PowerCool W300Harris / Victor OACraftsman 13 Speed Drill PressProTools Air/Hydraulic Bender48" BrakeCompressor, Notchers, Grinders, etc.
Reply:Yes, you need to re-size your photos so they don't cause the text to be chopped off, as has happened here.Some metals don't mix in all proportions; magnesium alloys are such an example. If you can't identify an alloy well, it often works to get some more of it from another similar item and use that as filler.Others here can probably suggest other alternatives; I prefer other uses for magnesium .
Reply:Fixed the size guys
Reply:I would contact the manufacturer of the valve cover and find out what it is, then go from there.MM350P/Python/Q300MM175/Q300DialarcHFHTP MIG200PowCon300SMHypertherm380ThermalArc185Purox oaF350CrewCab4x4LoadNGo utilitybedBobcat250XMT304/Optima/SpoolmaticSuitcase12RC/Q300Suitcase8RC/Q400Passport/Q300Smith op
Reply:4043 has silicon as the main alloying ingredient (in addition to aluminum.)5356 has magnesium as the main alloying ingredient. So if you believe this to be a magnesium alloy (well first can you explain to us why you believe this to be the case?), well then 5356 would be a better choice than 4043. Both are about equally readily available. It would be a mistake to be welding with a 4043 on an aluminum alloy that has no silicon in it to begin with. You could be concocting a crack sensitive mixture. Although generally speaking, a lot of cast aluminums have some silicon to help them flow in the mold.For for all those bubbles, it looks like some major porosity. Have you "baked" the valves cover to boil out as much of the oils before you weld? If not, you should give that a try. And do other methods to clean it as well. Like some solvents.Hydrocarbons, including oils, don't mix well with aluminum welding, because they emit hydrogen gas, which is soluble in molten, liquid alumunm than it is in solidified aluminum. So hydrocarbons, such as oils, can be a caude of porosity such as what you are seeing (on an interesting, really tiny bubble scale.)As for trying to weld magnesium with aluminum, I don't know how it would react because I've never tried it. Maybe someone who has tried it can chime in and tell us if it can result in this kind of "micro" porosity weld bead that you are getting.Best of luck
Reply:I'd say by the porosity and the fact that it breaks off it's magnesium or a good concentration of it. When you're welding it with the aluminum rod and the puddle is molten, can you take the puddle and move complete molten puddle with the rod like it's not fused together? Magnesium is lighter than aluminum so if it 'looks' lighter than you think it should be that's a rough way to tell. Shave off a few slivers with a coarse file, put them on a piece of 1/8" or so plate and heat the plate from underneath. If they burn bright white that would be a good indication that it's magnesium.....Mike
Reply:Vinegar will react with Magnesium. Easy way to tell.
Reply:Hello Jon K, the bottom line here is: if you are trying to weld aluminum to magnesium it won't work. Personally, I use silver nitrate to test for mag. vs. alum., if it's mag. the solution will turn black, if it's alum. it will stay clear. If you find that you have a mag. cover you'll need to machine your bosses out of mag. and then weld them to the covers with the mag. filler rod. Best regards, Allanaevald
Reply:Vinegar will react with Magnesium.
Reply:Hello mrmikey, likely it will make it turn black. Best regards, Allanaevald
Reply:Hrm. Ok - well, where can I get a like 1 - 1.25" diameter magnesium rod to make a boss out of?
Reply:Hello jon k, I would probably try googling "magnesium round stock" and see what comes up. If you are on the west coast possibly Pacific Metals might be a source. Good luck and regards, Allanaevald
Reply:Thanks Aevald- i had been searching. I'll search more. My usual mcmaster carr is failing me lol
Reply:Hello again Jon K, I have included a link that might just be the ticket for magnesium round stock. Best regards, Allan http://www.mandbmag.com/mag/rod.htmaevald
Reply:Originally Posted by Jon KThanks Aevald- i had been searching. I'll search more. My usual mcmaster carr is failing me lol
Reply:water heater anodes are magnesium,dont know if they come in the diameter you need.
Reply:Originally Posted by boatbuoywater heater anodes are magnesium,dont know if they come in the diameter you need.
Reply:Originally Posted by Jon KThanks Aevald- i had been searching. I'll search more. My usual mcmaster carr is failing me lol |
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发表于 2021-8-31 23:33:32