Inertia Welding

[TNT]

I’m putting this in LF section since I told Chris Dan’s son whom has an interest in welding about a project I've worked on involving Inertia Friction Welding. It’s costing a lot of money, and the welding house is getting a lot of rejections from surface imperfections penetrant inspection is detecting. Material is Nitronic 60 stainless steel bar which has better galling and wear properties for the threads in this design than normal 15-5PH or 17-4 stainless, I will show later. For now download the brochure from this website: NITRONIC 60 (Alloy 218) (UNS S21800) Wear and Galling Resistant stainless steel-Fe 63, Cr 17, Mn 8, Ni 8.5, Si 4, N 0.13 Alloy , and read through first few pages on galling, wear, and temp apps like motors. Also watch the video on the welding,

[ame="http://www.youtube.com/watch?v=-aEuAK8bsQg"]Inertia Friction Welding Demonstration - Manufacturing Technology, Inc. - YouTube[/ame]

There is always what is called a “knock down factor” in welding, moreso fusion welding, on the strength of material. Friction has very little since there is no “heat affected zone” like fusion where the molecules are large outside the weld bead. Friction weld produces a “solid state” weld, used on plastics too.

Got questions just ask and if don’t know the answer I have friends that do….be back later as time permits.

PS: You jam on that guitar btw keep practicing to the fast metronome or dads drum machine.

 

[TNT]

Here is a drawing view of my part a housing a wrench goes on the hex section, you can see the inertia friction weld symbol, pic of the assembly shown at the manufacture installed. Housing halves comes to weld house in hex bar, are machined to OD on a lathe, then welded, two end fitting's machined out of 15-5 PH cres stainless(not harder nitronic) are threaded into the housing to make the assemble. The threads are RH/LH kinda works like steering tie rods on a UTV.

IFW is just as much a forging operation as welding, you can see in the photo this one passed penetrant inspect does not look welded no bead or "heat affected zone" at all and super strong. Big benefit is dissimilar metals like aluminum and steel with different melting points can be welded. Be nice if UTV's were welded this way ahh!

All this is controlled at the manufacture by specs, be back with more info on them for ya.

After that since the weld house is seeing lots of rejections they suggested fusion orbital weld we'll touch a bit on it next and how the part would have to be redesigned.

Then finally I came up with a machine part design that gets rid of the welding cost sorry buddy, that's why you see the 1.50 in the photo since I moved the wrenching hex to make it more machinable did not want to interfere, and the challenges with it.

 

[Dexter]

So if I understand this correctly, essentially, this type of welding creates a stronger bond between the two things being welded because it makes one seamless weld. Kinda like the two pieces never were two separate pieces, right? Traditional welding would be weaker than inertial welding because it bonds the two metals together, but they aren't completely bonded as there is a visible seam between them.
Thanks Terry, this is pretty interesting stuff.

 

[s2k1]

Some pretty neat stuff done in manufacturing these days!

 

[TNT]

So if I understand this correctly, essentially, this type of welding creates a stronger bond between the two things being welded because it makes one seamless weld. Kinda like the two pieces never were two separate pieces, right? Traditional welding would be weaker than inertial welding because it bonds the two metals together, but they aren't completely bonded as there is a visible seam between them.
Thanks Terry, this is pretty interesting stuff.

You got it buddy, spot on, you learn fast!

Some pretty neat stuff done in manufacturing these days!

Actually, this design has been around past 25-years. The California supplier not far from you is a ma-and pa shop now that is all the sudden failing penetrant. We don’t know why they scrap parts before we can see them. We think it’s porosity and something in the penetrant process…hopefully, I’ll get some pics and the reason soon.

I don’t see a lot of friction welding, even though it is nothing new I think it's still being developed like you said. I was involved with an aluminum frame about 20 feet in diameter, we changed to “Friction STIR Weld” , it failed prototype due to improper loads analysis(was cracking too much on welds, it IS still a weak point despite how pretty it is, not as much as fusion) so we backed out to a different design since we had no time and money to develop it.

[ame="http://www.youtube.com/watch?v=jCe8-QYKZf4"]Friction Stir Welding Demonstration - Manufacturing Technology, Inc. - YouTube[/ame]

What I’m struggling with more is finding machine shops that can handle advanced technology, its come a long way past 25 years since this design was released, more on that later when I show you the guts of this thing….

 

[66cummins]

That is some cool stuff Terry.

 

[TNT]

Here is the IFW Military(MIL) spec the welders and designers bible, specs can come from all kinds of places….internal, government, societies like SAE, etc…download file skim through this: MIL-STD-1252 - INERTIA FRICTION WELDING PROCESS PROCEDURE

Covers the following,

Lack of bonding or Center defects
Flash, excess material from forging process equal on ID/OD for tubes
Weld energy
Faying surface
Thrust force
Material
Heat treat
Design considerations
Inspection

My design is class 11, flash removal not necessary see para 1.2 Also take note of the wide range of materials that can be IFW and those that can’t page 5, 6.

The penetrant spec is internal it covers,

Liquid sensitivity level
Developers
Solvent removers
Halogen and sulfur content
Facilities and equipment
Surface prep including weldments
Oven temp range
Penetrant dwell time
Removal
Fluorescent light examination
Inspection

 

[TNT]

Here what the supplier and manufacturing guys want to go to, Orbital Fusion Weld, kinda like IFW. Nicer looking and stronger than what you see on UTV chassis, still has to pass non destructive test. I am still working out the machine part bugs, no weld, machining hard Nitronic which has the Rockwell C twice of 15-5 CRES steel is not an easy task, show it next, so we might end up Orbital if I can not design and part that is lower cost to machine. Some of these steels are harder and stronger than we see in automotive and UTV's chassis.

[ame="http://www.youtube.com/watch?v=joqdlzMCZGA"]Orbital Welding by Polysoude - Closed Weld Heads MW - YouTube[/ame]

 

[TNT]

Here’s a pic of the part with flash to the right of the blue. It is designed such that flash can only accumulate outward that is ground off, buffed, and polished.

Also pic of penetrant(white stuff) inspect under black light of the IF-weld. Penetrant only picks up surface imperfections, if we want to see deeper we use xray. You can see the porosity in the rectangular area of around .005. In bending it can cause a tension surface crack, but since like the tie/radius rods on UTV’s this design sees none or should not, my disposition is to use as is, no repair or scrap. You can’t see this porosity by the naked eye. We have not figured out why we are seeing porosity, my thought is hot/cold spots surfacing, our Materials Technology Engineer I refer to as Men in White lab coats is going to chop one up in our lab maybe xray if he can find some budget, I'll be paying the lab a visit later IF it happens will keep you all posted....this is what we do for the Fam baby!