The Bucket Foundry

[ken seeber]

This RSP looks to be good stuff Grumph. What is interesting is pouring the small stream of liquid alloy onto the copper roller. Possibly some good safety practices required here. The guts of the process is the very quick solidification to maintain the Silicone in a fully dissolved state. What we do, which is what the industry standard practice is, is to use a phosphorous master alloy addition to the melt, this ensuing (refining) the Si remains in solution (much more so than without any refinement method), but clearly not anywhere near the RSP level.
Then it looks like it is extruded in what they call the “consolidation” step. This looks like a basic extrusion process, but to preserve the Si in solution, this would have to be done at a relatively cool temp. Well I think so.
Anyways, the nett result is that you have a really expensive, strong material, and one that could only be machined or maybe coldish forged, or, as Frits does, using the EDM process.
Anyone got any large diameter copper rings and an old extrusion press kicking around????????????

[Flettner]

My attempt at squeeze cast / forging a piston. Story has already been told, needless to say there was a lot of molten aluminium spread around the workshop.

[WilDun]

My attempt at squeeze cast / forging a piston. Story has already been told, needless to say there was a lot of molten aluminium spread around the workshop.

Gawd, is there anything you haven't tried?

So did you use a slow squeezing process to follow the shrinkage, or an almighty hammer blow, as in forging?

[Flettner]

Same Frits, but my 24% alloy was somewhat cheaper as you can see.
Will, it started with an idea to forge my own pistons (to get around the bucket racing piston rule) I made this tall structure in my shed with a slide way rail going up into the ceiling. Onto that slide I attached a LARGE piece of plastic extruder machine as the weight, cool I thought. Made the die as you can see, on my drill mill and Boxford lathe, put some lead in the die and pulled the trigger (a piece of string tied to a latch holding the weight back in the roof) the outcome was abysmal with the die only going into the lead about 20mm even after more shots. Clearly I had underestimated the force required to forge a piston. thinking back if I'd heated the lead there would have been a different outcome but you learn as you go. So I thought the aluminium is going to need to be just off molten so I melted a pot of LM13, tipped it into the die and waited until the skin looked set. I went to pull the string but thought perhaps I should stand behind the door, you know, just in case. Well all hell broke loose as there was molten aluminium everywhere with small fires starting in places. Good idea to stand behind the 'health and safety' door, what a mess as the alloy was still molten inside the die under the solidified skin. As I was cleaning up my shed some years later, when we moved house, I was still finding bits of solidified aluminium from that 'experiment'. Wife put a stop to it! (thankfully).

[Grumph]

I can think of less complcated ways to hurt yourself...

Pretty sure i mentioned the guy down here squeeze casting much earlier in the thread - way back.

When he described it to me, it was pretty much a steel piston pump linked to a long hand lever - the lot acting on the feeder channel leading to a male/female metal die. Let it fill and while semi solid, lean on the handle - carefully. Apparently, as you found, the trick is to judge the right moment to apply pressure...
I believe he had a fairly high remelt rate.

[WilDun]

Well all hell broke loose as there was molten aluminium everywhere with small fires starting in places. As I was cleaning up my shed some years later, when we moved house, I was still finding bits of solidified aluminium from that 'experiment'.

That was a good way to learn a lesson! - I did the same more or less last year but with wax (think I mentioned it) I poked the crust hard with a stick and the molten pool shot up and covered me with hot wax - that was bad enough, thank God it wasn't aluminium as in your case! - but we live and learn (usually) - pioneers have all tended to be brave.
Is there any reason why we can't just slowly squeeze it with some sort of arrangement (workshop press maybe) which uses a hydraulic jack?

I remember being told that melting (remelting) high silicon aluminium will often tend to burn off the silicon - anyone know anything about that?

[Michael Moore]

Instead of squeeze casting what about hot isostatic pressing to "densify" the casting?

https://en.wikipedia.org/wiki/Hot_isostatic_pressing

Hot isostatic pressing (hipping) can be used for upgrading castings, densifying presintered components, consolidating powders, and interfacial bonding. It involves the simultaneous application of a high pressure and elevated temperature in a specially constructed vessel. The pressure is applied with a gas (usually inert) and, so, is isostatic. Under these conditions of heat and pressure, internal pores or defects within a solid body collapse and diffusion bond. Encapsulated powder and sintered components alike are densified to give improved mechanical properties and a reduction in the scatter band of properties.

Fundamental aspects of hot isostatic pressing: An overview
H. V. Atkinson, S. Davies

https://www.youtube.com/watch?v=BsnzgsEXT_A

cheers,
Michael

[Grumph]

Instead of squeeze casting what about hot isostatic pressing to "densify" the casting?

cheers,
Michael

God, Michael, to a Kiwi, that's like a red rag to a bull - I can see an even bigger explosion coming....

[Ocean1]

God, Michael, to a Kiwi, that's like a red rag to a bull - I can see an even bigger explosion coming....

The Russians made tank hulls by explosive forming big panels. Less welding.

Not a new process, but the size of the bang required to draw plate that heavy into shapes that deep is hard to imagine.

[Kickaha]

The Russians made tank hulls by explosive forming big panels. Less welding.

Not a new process, but the size of the bang required to draw plate that heavy into shapes that deep is hard to imagine.

I've seen a yacht hull done like that, a big concrete mold full of water, massive big steel plate and some explosives

Fuck knows what it was about but it was on a doco on tv

[Frits Overmars]

Instead of squeeze casting what about hot isostatic pressing to "densify" the casting?
https://en.wikipedia.org/wiki/Hot_isostatic_pressing
https://www.youtube.com/watch?v=BsnzgsEXT_A

All Aprilia race cylinders were hipped. It stopped the bridges between the main and auxiliary exhaust ports from cracking.

[Flettner]

Sleeve engine, need to make the balance shaft / water pump drive and the gears to drive them. Frightningly close to running attached to the rear wheel this time. Still need to do the chambers but that's not a problem
And the air box.

[F5 Dave]

Que the stand up wheelies in shorts in between the sheep video

[ken seeber]

BREAKING NEWS !!!!!!!!!!!!!!!!
Nope, no breaking news cos nothing broke. But the sliding cylinder engine did run today, albeit with a few carby isues. Full length feature film coming to your local cinemas soon.

[Frits Overmars]