3D printed pistons

[e36jon]

Strad: Kudos on finding the thread. I remembered the conversation but couldn't find it... The 'new and improved' part of the conversation is using BeAl alloys with the 3D printing process, if possible.

I did a bit of searching and found that a number of the available BeAl alloys (Actually referred to as MMC, as Tommy Cookers said.), in solid form (Billet?), are made from powder precursors. I could not find raw powder though. There are a number of research articles on doing 3D printing with the material though, so it sounds like we'll see it soon enough.

Looking at material properties for one of the BeAl alloys it said ~20% lighter than a straight aluminum alloy for the same application. So, with the 3D printing weight reduction of 10% plus a 20% for a BeAl material substitution we'd have a ~30% weight reduction with no compromise other than increased cost. Yes, I am ignoring all of the details that would determine viability of the material switch like thermal conductivity, ductility, etc. Still though, 30% weight reduction, cool.

[PlatinumZealot]

I still want to understand why the shown piston has a bubbly looking crown and how that affects flame propagation.

it was designed to fit with the injector spray pattern more likley. You see the star shape?
The injectors are sensitive to direction they face and always fit so that the sprays point in the designated direction always. So the fingers are there for flame dynamics more likely.

[PlatinumZealot]

Tommy Cookers: Great post. I hadn't really considered how challenged our existing vocabulary would be with all of this new technology. I have seen 'PM' for 'Powdered Metal' used as a prefix and then a reference to 'alloy' after that. In the case of the Pankl Ti Cosworth conrod that I have, which is a PM Ti alloy that couldn't be made any other way (Sorry, I lost the exact alloy description...), I don't think they could have used it if it was a MMC. F1 had banned composites for engine components, right? This is me guessing / speculating / wondering as I am no expert on this.

Within the PM world my understanding is this (See earlier comment about not being an expert): The 'alloying' part of the process happens at a very fine, almost molecular level. This is necessary to get the actual material properties. The creation of the powders that are then used to either create billets of the new material or for feed-stock for 3D printers is happening on a much much larger scale. 100,000X? So, the 3D printer is welding together balls (The powder) of the new alloy. All this to say that the BeAl alloy, if it could be made into a powder, would probably work in the 3D printer. The GE turbine blades being made in the TiAl material had to do a bunch of work to get that material to actually work. They had to sort out a bunch of process details to finally get usable parts. So, BeAl may be absent because it can't be made into a powder, or it doesn't work well with the 3D printing process, or? At least we know what to get you for Christmas ;VP ...

It is not really a new technolgoy.. It was in the textbooks when I was in UNI.... Things are more refined... Better materials... More processing power... But.. More or less the samw stuff i have been seeing in the old text books. Like the old Computing and CAD books...
We see more computer savvy engineers with access to technology... And cheaper technology.. More research.. A bigger idea pool.. But not necessairly new because I wouldnt have known about it from twenty years ago!