What's the alloy? What's the die material? What pour and mold temp ranges did you try and at what temp did you demold? Hot tears like that can occur from just allowing too much cooling before demolding Best, Kelly
1. The alloy, is a car alloy wheel. 2. Die is 6082 with a boron coating 3. The least cracking was pour temp as low as possible, too low to flow into details, and mould really hot from last pour. Demoulding done about 2 -3 mins after cure, natural cooling. Temp: shrinking the welding glove degC. Tried adding a makeshift higher sprue but made no improvement.
Die casting requires good knowledge of the freeze temps and hot properties of the casting alloy and close control of the mold temp. Without knowing the composition of the casting alloy and precise temp of the mold, the odds are a bit stacked against you. If the wheel alloy happened to be 356, the coefficient of linear thermal expansion and melt onset temps aren't greatly different than 6082. Similar coefficients probably work for you but limitation of mold temp does not. That means you will have to operate the mold colder than other more typical die materials. It makes it much more difficult to estimate and time the demold temp. From a practical standpoint, I understand using scrap alloy and tooling plate for the mold, but there's really no reason you couldn't monitor mold temp more closely. -Just imbed a k-type TC in the die/mold body. You should probably be shooting to demold a couple hundred F below hot short temp. Best, Kelly
Die casting... isn't that the dream for many? I did as well made a mold for a decorative horseshoe a while back. Made probably 10-15 pieces so far. This pic is from 2022. The mold is older and was just a try; I always planned on making another one but never did. I had some trouble getting it out, it's far from perfect but good for gifting with my sinkers. The part is from 0.8 to 1 cm thick, 10X8 cm height to width. No hot tears but I think it's because the mold is quite thin so gets pretty hot with one or two pours.
