Forging Aluminum? What's the process?

[Ludachris]

Anyone here know what's involved in creating forged aluminum pieces? I'm assuming you need to create molds and there are obviously different types of metals. But what is the process and what might prevent someone from creating forged pieces? Are the tools super expensive?

 

[bane3d]

I wish you luck. I've done it with lead and that melts at a much lower temperature. I had trouble getting out the impurities and settling the bubbles. My end product always seemed to have some flaws. Of course I was 13 at the time and probably didn't have the patience to do it properly (or with adult supervision). Here is a how to guide that I found on making some ingots: Ultimate Guide to Making a Cheap but Effective Aluminium Forge. What exactly are you working towards?

d

 

[Flash]

I know it's not a definite answer. But it will give you a general idea. It's very boring, but informative. Another option that I have actually used is called spin casting. Enkei uses this form on some of its wheels. It is said that spin casting will produce the aluminum to look similar to forging at a molecular level.

<object width="425" height="344"><param name="movie" value="http://www.youtube.com/v/eEq8C5ZIezY&hl=en&fs=1&color1=0xcc2550&color2=0xe87a9f"></param><param name="allowFullScreen" value="true"></param><embed src="http://www.youtube.com/v/eEq8C5ZIezY&hl=en&fs=1&color1=0xcc2550&color2=0xe87a9f" type="application/x-shockwave-flash" allowfullscreen="true" width="425" height="344"></embed></object>

 

[Ludachris]

I wish you luck. I've done it with lead and that melts at a much lower temperature. I had trouble getting out the impurities and settling the bubbles. My end product always seemed to have some flaws. Of course I was 13 at the time and probably didn't have the patience to do it properly (or with adult supervision). Here is a how to guide that I found on making some ingots: Ultimate Guide to Making a Cheap but Effective Aluminium Forge. What exactly are you working towards?

d

Yeah, I saw that article too when searching google. I'm trying to figure out what it would cost to create some forged lower control arms for the 1G. I'm sure it would be somewhat expensive, but I'd like to learn more about it.

 

[TunaTalon]

Forging is the process of using force to shape metal. All you need (in the most general sense) is a means to heat the metal to red or white hot and a hammer. And of course the skill set of a blacksmith. In industrial applications the hammers are power driven and the metal is forced into pre-shaped dies.

The process of forging aligns the grains of the metal and tends to make stronger parts than casting. In casting molten metal is poured into moulds and the grains end up randomly aligned.

See FIA: Forging Facts - What are the types of forging processes? for a more technical description.

 

[Ravenous]

Check out the Gingery series of books. The first book in the series, "The Charcoal Foundry" talks about mold making and casting aluminum but it doesn't cover forging. I was thinking about making some control arms myself but didn't think the standard casting would be strong enough.

 

[pneumo]

Have you considered CNC machining? Even a forged part needs to have the pivot points machined in order to meet the tolerances. Maybe start with a flat billet, machine it to shape, then weld on a flange to attach the swap bar. Maybe make the swaybar mount adjustable.

 

[Ludachris]

Have you considered CNC machining? Even a forged part needs to have the pivot points machined in order to meet the tolerances. Maybe start with a flat billet, machine it to shape, then weld on a flange to attach the swap bar. Maybe make the swaybar mount adjustable.

I was thinking the sway bar mount could just be incorporated into the mold as a female thread. You could then use adjustable solid end links for adjustment.

 

[Ludachris]

Forging is the process of using force to shape metal. All you need (in the most general sense) is a means to heat the metal to red or white hot and a hammer. And of course the skill set of a blacksmith. In industrial applications the hammers are power driven and the metal is forced into pre-shaped dies.

The process of forging aligns the grains of the metal and tends to make stronger parts than casting. In casting molten metal is poured into moulds and the grains end up randomly aligned.

See FIA: Forging Facts - What are the types of forging processes? for a more technical description.

So does that mean that all factory aluminum control arms are made individually by hand? Or are they cast pieces?

 

[TunaTalon]

Not cast. Casting involves pouring molten metal into a mold while forging involves shaping metal that is still hard (or heated to a plastic state) with force.

In a typical forging production line the aluminum stock is manually fed into a press and the press applies enough force to deform (forge) the stock into the shape of the tool and die in the press. The press capacity can be over 1000 tons.

After forging into the rough shape the parts are heat treated and machined to the final dimensions.

Please see ALFOT Technologies Co.,LTD for a description and pictures of a forging production line.

 

[SethA]

What gives forged parts much of their strength is the favorable grain structure from being worked into shape. A cast part will have a random structure that is weaker.

Forging videos from Scot Forge.

YouTube - ENMF 417 Mini Project Group 7C(Die Forging)

Seth

 

[pneumo]

Have you thought about changing the geometry of the control arm to make the car handle better? This could be done by moving the outer ball joint forward by approximately 1/2". This would add approximately 1/2* of caster and improve weight distribution slightly.

 

[cioc]

My profession is in quality control for an aerospace engine manufacturer. I have been in several forge and casting shops and can tell you that the presses that are used in aerospace are in the 10,000 + Ton variety. There are some facilities we deal with overseas that have presses in excess of 30K Ton. When you see the magnitude of these presses you start to wonder what size machine/facility made the presses. Nevertheless you couldn't just heat aluminum and hammer it into shape and expect the strength required to sustain the forces it would see. In general, forgings are stronger than castings however their are also some very advanced casting technologies that produce materials that are actually STRONGER than most forgings. For example, castings are typically "equiax" or as SethA pointed out, a random crystallization of the metal once it is cooled which creates several grain boundaries which are subject to failure. Sophisticating casting facilities however, have the capability of controlling the rate of cooling to "grow" the grains in a specific direction. This type has significant strength advantages over "equiax" castings. Furthering this technology has led to a "single crystal" casting which is the strongest version. If interested in any of these technologies, read this: Lost and foundry
I work for Pratt & Whitney and Howmet is one of the casting facilities I am responsible for. So, the technology for producing a superior casting that would exceed our requirements for strength, durability, net shape and weight are out there. The cost of design, mold manufacture and casting would most likely put us all in the poorhouse....tenfold.

Forging is almost as costly. Dies must be manufactured to the shape of the control arms which would also prove to be extremely costly. What's wrong with the tubular option that Polk came out with? Nevermind it's no longer available but what about coming up with an even better design...perhaps with the ability to ADJUST CASTOR/CAMBER through the use of heim joints etc. I'm also in the know of an aerospace tubing manufacturer that we could contract to make these. Orbital welds, heat treat, exotic materials...the skies (and budget) the limit.

Ludachris,
To answer your original question...yes, tooling is EXTREMELY expensive.

 

[Ludachris]

Just wondering. I figured it wouldn't be cost effective but I'm always looking for ways to improve upon what we have.

 

[TunaTalon]

I like the cioc suggestion of going to a different technology.

After all, how can you be better if you're not different?

 

[Eagle 5]

If I had a spare control arm I could work on making a model of what we could use or want. Mainly need one for just the mounting points/ locations. Modeling is not that hard considering I pretty much do it every day at work. Maybe I can take a trip to a junkyard here and pick up an old one.

 

[cioc]

I have a spare set of control arms. The only drawback is that the balljoint holes are slightly oversized due to me getting a little "happy" with my dremel. If this effort gets serious enough, I'd be willing to split the shipping costs with someone.

Since we have none, I'm not familiar with caster adjustments. Where are they typically made?...at the strut mount up top?...or changing the position of the entire hub assembly?

 

[Zmann42087]

What about cast aluminum control arms? I know forging generally leads to a product that is stronger and lighter than their cast equivalents, but the cost of forged manufacturing is not always feasible. I was thinking something similar to the Specialty Products 2g cast aluminum control arms might be a good upgrade. It would be a little more realistic in terms of production cost but still provide improvements over the factory 1g pieces.


EDIT: I just realized in the description link I posted, it says the control arms are forged aluminum. But on RRE's page here it says they're cast aluminum. Now I'm just confused and not sure what they are.

 

[turbosax2]

SPC's site says they're forged.

SPC Application Search - Product

 

[Zmann42087]

^^^ Thank you, sir. I was having trouble finding that description on SPC's site. I was about ready to call Mike Welch.

Well, seeing as how SPC obviously has the capabilities to produce forged arms, I wonder if they could be badgered into coming up with some for the 1g.

 

[Defiant]

I'm trying to figure out what it would cost to create some forged lower control arms for the 1G.

You might want to take a gander under a Hyundai.

But no, you won't be having any made.... unless Colorado does a much better job of running their Lotto than they do here.

 

[pneumo]

Since we have none, I'm not familiar with caster adjustments. Where are they typically made?...at the strut mount up top?...or changing the position of the entire hub assembly?

Whiteline makes (made?) a caster bushing. It replaced the rear lower bushing on the front control arm- the big one with the hole in it. Their replacement bushing had the hole drilled off center so it moved the hub forward. I also recall seeing some upper camber plates that also had caster adjustment built in. They moved the upper strut mount rearward.

I still say you should look into CNC machining. It's adaptable and doesn't rely on large production runs to diffuse the startup costs. In the bicycle industry a CNC machined part is considered to have the same potential for strength and weight as a cold forged part.

 

[slipstream808]

Jees. You guys are crazy with all this innovative I wanna make stuff to make my car better stuff. Can't we be happy with what we have?

No... we can't. I can't either. I just WISH there was a way I could help you guys out.

 

[logic]

DIY.

http://www.backyardmetalcasting.com/

 

[drivemusicnow]

Figure startup cost for casting a control arm is >$10K and that's without the machining processes that would be required to bring in the tolerances.

Forging would require >$30K in tool and die costs.

My opinion is machined billet, but I made that argument in the ball joint thread.