Ferrari Power Unit Hardware & Software

[PlatinumZealot]

Can your sintered iron of high copper content be easily machined though?

Why wouldn't it be?

You don't think it is a fair question? A few reasons actually...

[Maritimer]

Can your sintered iron of high copper content be easily machined though?

Why wouldn't it be?

You don't think it is a fair question? A few reasons actually...

Oil-based coolant, Cermet or PCBN tooling, and high speeds should work fine no? Only thing I can really think of would be copper in the swarf galling the tool but I'm not aware of buildup being an issue with non-steel tooling. What am I missing?

[63l8qrrfy6]

As I've mentioned sintered copper steels are machined for valve seats and guides.
Remember that F1 used to machine TiAl, they won't shy away from some steel.

[PlatinumZealot]

Why wouldn't it be?

You don't think it is a fair question? A few reasons actually...

Oil-based coolant, Cermet or PCBN tooling, and high speeds should work fine no? Only thing I can really think of would be copper in the swarf galling the tool but I'm not aware of buildup being an issue with non-steel tooling. What am I missing?

Not saying steel powder forgings can't be machined because they are. They are also known to be less machineable. And you will be doing a tonne of machining on the forged shape to turn it into that intricate lightweight peice.

Higher Porosity leads to lower thermal condcutvity disconttinuous cutting despite more copper in it, and the higher carbon content and pearlitic mircrostructures makes tool wear more. One might argue that there are newer additives and techniques to imorove machineability and that is true

Just saying, the worse bulk thermal conditivy and lower strength and worse machineability than wrought forged steel... Might as well you machine the wrought forged steel instead and be done with it.

[63l8qrrfy6]

thermal conductivity is better - that's the whole point of sintered copper steels !

[Maritimer]

Not saying steel powder forgings can't be machined because they are. They are also known to be less machineable. And you will be doing a tonne of machining on the forged shape to turn it into that intricate lightweight peice.

Higher Porosity leads to lower thermal condcutvity disconttinuous cutting despite more copper in it, and the higher carbon content and pearlitic mircrostructures makes tool wear more. One might argue that there are newer additives and techniques to imorove machineability and that is true

Just saying, the worse bulk thermal conditivy and lower strength and worse machineability than wrought forged steel... Might as well you machine the wrought forged steel instead and be done with it.

Copper increases conductivity, thats the while purpose of putting it in there. The porosity isn't a huge deal when using hard tooling like PCBN, it's extremely abrasion resistant- you use it to shape grinding wheels for example- so over a single production run wear would be negligible and certainly easy to account for on any modern CNC mill. Also to consider is that these processes would be finish machining, so no more than .015" would ever be removed; you could even grind the work to size if your moulding was close enough to final spec, within .005" or so.

[johnny comelately]

Wouldn't there be a loss of power and a weight penalty when using high conductivity materials like these?
The aim is to keep the heat in the chamber and working (hence the advantage of carbon pistons, coupled with weight reduction), so if my mentioned cap in hand approach failed, the heat reflective coatings path would be best?

[Singabule]

Wouldn't there be a loss of power and a weight penalty when using high conductivity materials like these?
The aim is to keep the heat in the chamber and working (hence the advantage of carbon pistons, coupled with weight reduction), so if my mentioned cap in hand approach failed, the heat reflective coatings path would be best?

Agree, if one engine can keep heat within their CC, so the exhaust mass is larger, you can harvest more electricity. Also, you can decrease size of oil cooler. Detonation is not an issue anymore coz very lean mixture. In this case, alu is more favorable than Steel, and ceramic or carbon composite would perform the best

[wuzak]

Wouldn't there be a loss of power and a weight penalty when using high conductivity materials like these?
The aim is to keep the heat in the chamber and working (hence the advantage of carbon pistons, coupled with weight reduction), so if my mentioned cap in hand approach failed, the heat reflective coatings path would be best?

Agree, if one engine can keep heat within their CC, so the exhaust mass is larger, you can harvest more electricity. Also, you can decrease size of oil cooler. Detonation is not an issue anymore coz very lean mixture. In this case, alu is more favorable than Steel, and ceramic or carbon composite would perform the best

I think the exhaust mass flow rate will be the same. The exhaust energy, however, would be increased by having lower conductivity piston materials.

[godlameroso]

Ultimately the goal of combustion is to create a change in temperature, the bigger the change in temperature the more power you can generate. The change goes both ways, you can lower the starting temperature, and increase the end temperature, both accomplish the same thing, increase the change in temperature. The change in temperature causes the pressure increase, the thing that is doing all the work. Part of the reason the FIA introduced the ambient +10C intake temperature clause? It sets a lower limit, and forces you to make power via heat release over ambient. The massive air dilution works to not just lower exhaust temperatures, but also increase the exhaust density, and increases the mass of parcels of cooler air between the exhaust pulses increasing the temperature delta of the pulses reaching the turbine. I suspect very sophisticated wastegate control actually aids turbine recovery.

[gruntguru]

The "low" temperature that is relevant to thermal efficiency is the temperature of the working fluid when heat is rejected. In a piston ICE, heat is rejected during the power stroke through the chamber walls then at BDC to the exhaust so there are many different temperatures in play. Fortunately most of the heat is rejected after BDC to the exhaust and the relevant temperature is the gas temp at EVO (essentially the cycle has ended at this point.) Heat rejected during the power stroke (at high gas temperatures) is bad for TE and the earlier in the stroke (higher temp) the "badder" it is.

[PlatinumZealot]

Not saying steel powder forgings can't be machined because they are. They are also known to be less machineable. And you will be doing a tonne of machining on the forged shape to turn it into that intricate lightweight peice.

Higher Porosity leads to lower thermal condcutvity disconttinuous cutting despite more copper in it, and the higher carbon content and pearlitic mircrostructures makes tool wear more. One might argue that there are newer additives and techniques to imorove machineability and that is true

Just saying, the worse bulk thermal conditivy and lower strength and worse machineability than wrought forged steel... Might as well you machine the wrought forged steel instead and be done with it.

Copper increases conductivity, thats the while purpose of putting it in there. The porosity isn't a huge deal when using hard tooling like PCBN, it's extremely abrasion resistant- you use it to shape grinding wheels for example- so over a single production run wear would be negligible and certainly easy to account for on any modern CNC mill. Also to consider is that these processes would be finish machining, so no more than .015" would ever be removed; you could even grind the work to size if your moulding was close enough to final spec, within .005" or so.

The moulding of powder forgings are very limited in the shape so it would be a lot of machining to get the piston like you see in the Audi piston photos. The F1 piston would be more complicated as well.

[PlatinumZealot]

thermal conductivity is better - that's the whole point of sintered copper steels !

http://www.scielo.br/img/revistas/mr/v1 ... 6-gf12.jpg

Tell me the alloy that you are thinking of for the pistons...

[ncassi22]

thermal conductivity is better - that's the whole point of sintered copper steels !

http://www.scielo.br/img/revistas/mr/v1 ... 6-gf12.jpg

Tell me the alloy that you are thinking of for the pistons...

How would this stuff work? AKA Iron Man's suit material
https://phys.org/news/2016-07-lab-titan ... teels.html

[Maritimer]

Not saying steel powder forgings can't be machined because they are. They are also known to be less machineable. And you will be doing a tonne of machining on the forged shape to turn it into that intricate lightweight peice.

Higher Porosity leads to lower thermal condcutvity disconttinuous cutting despite more copper in it, and the higher carbon content and pearlitic mircrostructures makes tool wear more. One might argue that there are newer additives and techniques to imorove machineability and that is true

Just saying, the worse bulk thermal conditivy and lower strength and worse machineability than wrought forged steel... Might as well you machine the wrought forged steel instead and be done with it.

Copper increases conductivity, thats the while purpose of putting it in there. The porosity isn't a huge deal when using hard tooling like PCBN, it's extremely abrasion resistant- you use it to shape grinding wheels for example- so over a single production run wear would be negligible and certainly easy to account for on any modern CNC mill. Also to consider is that these processes would be finish machining, so no more than .015" would ever be removed; you could even grind the work to size if your moulding was close enough to final spec, within .005" or so.

The moulding of powder forgings are very limited in the shape so it would be a lot of machining to get the piston like you see in the Audi piston photos. The F1 piston would be more complicated as well.

If they're going for a floating skirt then yes, that would be more difficult without making them from multiple segments.