Wondering if anyone knows what Aluminum alloy the IRS lower arms are made of. Better yet, does anyone know the original supplier of the arms? Would like to get the info right from them, but also cool if I find it here...
Any metallurgy gurus here? Curious about IRS aluminum arms..
- Thread starter jrgoffin
- Start date
What do you need or want the info for?
A superior lighter replacement, possibly more compatible with coil over loading?
Kenny Brown used to make tubular steel lowers, but many had some build quality issues.
You have now made me very curious!:dw: LOL!
A superior lighter replacement, possibly more compatible with coil over loading?
Kenny Brown used to make tubular steel lowers, but many had some build quality issues.
You have now made me very curious!:dw: LOL!
Ha, you are curious!!
Actually, just wondering about the permanent-mold casting process and the alloy as it pertains to heating the arm again. Experimenting with a spare set and the use of some "low" heat (about 500F) to burn/melt out bushings in a machine-shop oven. Knowing the exact alloy would give me some idea as to the tensile strength, hardness, and some of the other properties.
Not a big deal, just somewhat trivial. My friend that used to work for SVT is hopefully getting me in touch with one of the SVT engineers that designed the IRS, so hopefully my curiosity will be satisfied!
Actually, just wondering about the permanent-mold casting process and the alloy as it pertains to heating the arm again. Experimenting with a spare set and the use of some "low" heat (about 500F) to burn/melt out bushings in a machine-shop oven. Knowing the exact alloy would give me some idea as to the tensile strength, hardness, and some of the other properties.
Not a big deal, just somewhat trivial. My friend that used to work for SVT is hopefully getting me in touch with one of the SVT engineers that designed the IRS, so hopefully my curiosity will be satisfied!
Interesting, now I am wondering too.:-D
There are so many alloys it's hard to say. 356-T6 is a pretty common high strength casting alloy for this application but that is nothing more then a guess. Heating it to 500 degrees may effect the temper and is something I would not do since this is a structural component. We use to stress relieve aluminum at 350 after welding but I would not go higher then that.
They are hollow core and appear to be displacement sand castings just looking at the surface finish.
I would just press them out and not take a chance melting them out which will be nasty. The sleeves will still have to be removed.
They are hollow core and appear to be displacement sand castings just looking at the surface finish.
I would just press them out and not take a chance melting them out which will be nasty. The sleeves will still have to be removed.
^This and nothing else
They are actually permanent-mold castings, not sand castings - if that makes a difference. Hopefully I'll get the info on the alloy right from SVT soon enough to know for sure. The 356 was one of my guesses, but there are still a handful of others to consider.
The process of melting the bushing out was not nasty at all, especially since it was not a concentrated, direct heat (like welding or a torch). In any case, the sleeves are prefectly clean (and didn't need to be removed anyway).
For those wanting to be in the know, I'll throw the info up here as I find out...
Not sure about them being a permanent casting just based on the surface finish. The mold of a permanent casting would typically be machined and somewhat smooth. You can texture the mold to achieve that finish but I don't know what purpose that would serve. Looks like a sand casting to me but I do know for sure. In engineering making assumptions will "kill you".
Your inside guy at Ford will need to pull the fab drawing and get this info off the fabrication notes. Generally only the guys in engineering can do that. It's likely the A-arms were outsourced. I worked at Rockwell Collins who use to be North American Aviation to see if they had scanned drawings of the P-51 Mustang just for grins (very long shot). Asked my manager about it and he stated the design was sold to Boeing. It's doubtful even those guys can get to it without jumping thru hoops.
I wouldn't be so sure about the nastiness of burning the bushing out. I use to be the Forman at a heat treating company years ago and occasionally he got plastic and rubber coated assemblies that the customer wanted us to heat and burn the coating off to recover the metal (lots of big electric motor field coils to get at the copper). It's a good thing we didn't get a surprise visit from the EPA during that process.
Your inside guy at Ford will need to pull the fab drawing and get this info off the fabrication notes. Generally only the guys in engineering can do that. It's likely the A-arms were outsourced. I worked at Rockwell Collins who use to be North American Aviation to see if they had scanned drawings of the P-51 Mustang just for grins (very long shot). Asked my manager about it and he stated the design was sold to Boeing. It's doubtful even those guys can get to it without jumping thru hoops.
I wouldn't be so sure about the nastiness of burning the bushing out. I use to be the Forman at a heat treating company years ago and occasionally he got plastic and rubber coated assemblies that the customer wanted us to heat and burn the coating off to recover the metal (lots of big electric motor field coils to get at the copper). It's a good thing we didn't get a surprise visit from the EPA during that process.
Yeah, I was going with the 'Permanent Mold' info right from many press releases and tech articles I dug up - they all said the same thing and none referenced sand casting. In any case, looking at the alloys, heat treatments, and temper designations, they are pretty wide-spread, so I won't know much until I hear back from the engineer at Ford. If it is the 356-T6 that was solution heat treated, they get them up to 1000F (after heating the mold to about 500F) for several hours before quench-cooling, so who knows how it all works with more heat after-the-fact.
Anyway, the bushing-burn job was simple, even on some other arms that I hit with mapp gas. Everyone mentions that the IRS cradle bushings were the pain - I had all four out pretty quick and had the bores nice and clean with the wire wheel. Worst case, I can do the same (with the drill too) on my spare lowers - just got impaitent and "burned-out", so to speak!
I do know that a company in Michigan called Benteler Engineering made the cradle and built up the IRS before it was delivered, but don't know if they were also the supplier of the arms. Hopefully more useless trivia to follow...
T6: 985 degrees for 12 hours, quench in water, age on room temperature 2 hours, temper at 350 for 2 hours. T4 you skip the temper but will turn to T6 over time. That's the process if I remember correctly. I've seen some pretty spectacular events during the heat treat process. We use to heat treat distributer cap contacts which were small aluminum cups and would be poured into the retort. On out fist run we were clueless and stupid and didn't cap the retort prior to heat treat (all 1000 lbs of it). Using the overhead hoist we dropped the retort into the quenching tank and it looked like a volcano erupting
showering us and the shop with hot metal parts and managed to empty the top basket :nonono: We were hopping around like Mexican jumping beans getting pelted with hot metal parts :lol1: Explosions.......you don't even wanna go there! ! If you have miss-behaved in life and want to know your fate go work at a heat treating company :fm:
Sounds like good times!!!
I was close anyway with the 1000F for the T6. What I'm still curious about (and not being a trained engineer) is if the initial mold and heat treatment temps are that high, how will an oven temp of 500F down the road have a negative effect on the alloy? I thought I understood the heat treating would continue the strengthening, but I'll keep reading.
On an odd note, there is a 14mm steel washer that is epoxied to the arm where the shock bolts in (keeping the metal sleeve in the shock from galling the aluminum). On one of my arms, that washer was still epoxied on, but the other had fallen off. This was after being in the oven for about five hours. Either that was some serious epoxy or the heat wasn't too detrimental (unless you are talking about the rubber in the bushings!). Even some of the crud in the spring seat was still stuck on!
In any case, I'll wait to find out more and let the curious know.
I was close anyway with the 1000F for the T6. What I'm still curious about (and not being a trained engineer) is if the initial mold and heat treatment temps are that high, how will an oven temp of 500F down the road have a negative effect on the alloy? I thought I understood the heat treating would continue the strengthening, but I'll keep reading.
On an odd note, there is a 14mm steel washer that is epoxied to the arm where the shock bolts in (keeping the metal sleeve in the shock from galling the aluminum). On one of my arms, that washer was still epoxied on, but the other had fallen off. This was after being in the oven for about five hours. Either that was some serious epoxy or the heat wasn't too detrimental (unless you are talking about the rubber in the bushings!). Even some of the crud in the spring seat was still stuck on!
In any case, I'll wait to find out more and let the curious know.
Metallurgy is a very involved science way beyond my understanding (I consider myself a 30 year novice noob in that area :nonono. All I know is to avoid applying heat especially around structural aluminum because I have no idea how I am effecting the temper of the alloy. I trust the engineers at Ford way more then myself to do the right thing which keeps me out of trouble.
Russ :beer:
. All I know is to avoid applying heat especially around structural aluminum because I have no idea how I am effecting the temper of the alloy. I trust the engineers at Ford way more then myself to do the right thing which keeps me out of trouble.Russ :beer:
I hear you on that, which is why I will be glad to get the info right from the engineer(s) who designed it. What is amazing though, is that the 356-T6 (assuming that is the correct alloy), still has a yield strength of 31 ksi, which if I am correct, translates out to 31,000 lbs/sq. ft.! That's still pretty damn strong!!
356 is a wonderful alloy but it's been around for decades. I wonder what new alloys are out there we don't even know about. Then again there are applications where you don't want 2024 or 7075 :nono:
On a side note, I can provide various heat treatments for people that need them.
Ah, a fellow heat treater :rockon:
Ever throw a snowball or ice cube in a salt pot?
My favorite was quenching wave washers in the Allcase
CAn't say I have. Who do you work for?
I use to work for New Haven Heat Treating in the early 80's
The snow balls would explode on contact with the 1800 degree cyanide. 2nd shift. We were young, stupid and bored :bored:
Quenching the wave washers caused a jet of super bright white flame to shoot out the outer door thru the pull rod opening about 15'. The front operator would pull the rod out and run! Then the lift operator would drop the basket into the quenching tank :coolman:
We had a gas explosion blow a 2 ton door off a furnace. Loosing a basket in the Allcase was the worst. Trying to wrestle it out of the quench chamber in a 1800 degree furnace with a flame curtain in front of you was hell :cuss: Then there were gas explosion in our belt fed annealer from air build-up. You would be feeding the conveyer and without warning BOOM! and would send the operator flying into the cardboard drums in front of the machine (it was more of a survival reflex then anything). Out of boredom I built a small smelting furnace and could melt anything up to brass and I was pouring casting using the investment cast process mostly aluminum. Word of caution: Don't pour molten aluminum into a cold mold :nono: :bash: :dw: :smmon: :-D
I hated that job but to be honest we had a lot of fun there and wouldn't trade the experience for the world. There were guys who worked there for 40 years. We were fresh out of high school.
The snow balls would explode on contact with the 1800 degree cyanide. 2nd shift. We were young, stupid and bored :bored:
Quenching the wave washers caused a jet of super bright white flame to shoot out the outer door thru the pull rod opening about 15'. The front operator would pull the rod out and run! Then the lift operator would drop the basket into the quenching tank :coolman:
We had a gas explosion blow a 2 ton door off a furnace. Loosing a basket in the Allcase was the worst. Trying to wrestle it out of the quench chamber in a 1800 degree furnace with a flame curtain in front of you was hell :cuss: Then there were gas explosion in our belt fed annealer from air build-up. You would be feeding the conveyer and without warning BOOM! and would send the operator flying into the cardboard drums in front of the machine (it was more of a survival reflex then anything). Out of boredom I built a small smelting furnace and could melt anything up to brass and I was pouring casting using the investment cast process mostly aluminum. Word of caution: Don't pour molten aluminum into a cold mold :nono:
:bash: :dw: :smmon: :-DI hated that job but to be honest we had a lot of fun there and wouldn't trade the experience for the world. There were guys who worked there for 40 years. We were fresh out of high school.
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