Strength of material...Cast vs Billet

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Hey guys.. Long time no post!Anyway, I've recently been getting into sand casting of metal car parts. So far, just simple aluminum pieces...no big deal.Well, I've been asked if I could make a car hub out of magnesium. I don't see any reason why I couldn't make the part, but my question is, would it be stronger than the "competitions" machined billet aluminum piece.I could make the hubs out of magnesium cheaper than machining a chunk of aluminum, so I could pass the savings onto buyers, but its not worth it if the pieces are going to be weaker.So... simple question. Is cast Magnesium stronger than machined billet aluminum?Thanks!!
Reply:Originally Posted by m73m95Anyway, I've recently been getting into sand casting of metal car parts. So far, just simple aluminum pieces...no big deal.Well, I've been asked if I could make a car hub out of magnesium. I don't see any reason why I couldn't make the part, but my question is, would it be stronger than the "competitions" machined billet aluminum piece.I could make the hubs out of magnesium cheaper than machining a chunk of aluminum, so I could pass the savings onto buyers, but its not worth it if the pieces are going to be weaker.So... simple question. Is cast Magnesium stronger than machined billet aluminum?
Reply:To the OP:You need to do some reading on what BILLET is. Most all metal is cast. (read molten and pored) before being processed to then be called billet. A sand cast (non vacuum) hub would be many times weaker (read brittle, having inclusions, less ductile, lower elongation...)   than a turned hub.
Reply:and forgings will be stronger also watch the market... also sometimes billet isnt really billet, they are just using the word for marketing purposes..tackleexperts.comwww.necessityjigs.comhttps://www.facebook.com/groups/mach...dingequipment/
Reply:I did a little googling and everything appears to be forged. I found this neat photo guide to making wheels.http://www.minitruckinweb.com/tech/w.../photo_01.htmlThis place sells forged blanks... that looks like a different design than above.http://www.allamericanwheel.com/wheels.html
Reply:Well... Most of this I already know  (Not trying to sound like an arrogant ***).The stock hubs are cast (not forged) aluminum. The cars (Porsche 944T) are often used as race cars, and it has been shown that when you exceed the Porsche recommended wheel/tire widths, the hubs are the first thing to break in hard cornering.So, there is an aftermarket company currently making billet (I know what billet is) hubs...and they are (IMHO) unreasonably expensive for guys that don't have semi-pro race teams.I want to make stronger (than stock) hubs, at a lower cost, for "regular" people. For some reason I cannot find accurate information on the strength of sand cast magnesium. I'm thinking that may be due to the fact that there is such a wide variety of casting techniques, and procedures. Thank you for the help so far though!
Reply:I'm thinking sand cast mag would be crap compared to sand cast aluminum.That being based on the castings brought to my shop for repairs.Miller Dynasty 700Miller 350P with Aluma-pro push-pullMiller 280 Dynasty with expansion card Dynasty 200 DXMigMax 215 Enuff power and hand tools to create one of anything..... but mass produce nothing!!!
Reply:Here's a link to a heat treat guide for mg. This should give you some values that may help you compare the two materials. There is also a table comparing aged (heat treated) and forged alloys.http://books.google.com/books?id=_iU...page&q&f=false
Reply:Originally Posted by m73m95Hey guys.. Long time no post!Anyway, I've recently been getting into sand casting of metal car parts. So far, just simple aluminum pieces...no big deal.Well, I've been asked if I could make a car hub out of magnesium. I don't see any reason why I couldn't make the part, but my question is, would it be stronger than the "competitions" machined billet aluminum piece.I could make the hubs out of magnesium cheaper than machining a chunk of aluminum, so I could pass the savings onto buyers, but its not worth it if the pieces are going to be weaker.So... simple question. Is cast Magnesium stronger than machined billet aluminum?Thanks!!
Reply:Originally Posted by forhireHere's a link to a heat treat guide for mg. This should give you some values that may help you compare the two materials. There is also a table comparing aged (heat treated) and forged alloys.http://books.google.com/books?id=_iU...page&q&f=false
Reply:there are several different types of forging processes that I am familiar with...The two types i've mainly worked in are impression forging and also rotary forging/roll forging... rotary forging is also called spinning/rolling, which is mainly in the wheel industry.. They do this as it cuts down on wasted material and also strengthens the aluminum wheel. I have been involved in a lot of prototype aluminum tractor trailer wheels, and also a lot of prototypes for ford motor company light/med/heavy duty trucks.. Impression die forging is when you have 2 dies cut to a particular part profile and you smash a piece of heated material between them, forging a shaped part.. I've done various dies for several axle and heavy equipment companies, also done many large piston dies. You can also do this process as cold work, if you have a large enough press. I've also made many coining dies, basically after a wheel is machined and the handling holes are cut or punched they have to be coined (deburred) wheel manufactures do not cut the material for this process, cutting the burrs off creates stress points in the material and will cause the wheel to actually fracture around the handling holes, so they make dies to coin the handing holes. Its basically 2 die halves and they set the wheel on the dies and press/coin radius' on the handling holes, which actually strengthens the perimeter of the handling holes..Last edited by brucer; 03-12-2012 at 06:13 AM.tackleexperts.comwww.necessityjigs.comhttps://www.facebook.com/groups/mach...dingequipment/