It doesn't look like any of the discussion mentions the embedded parts (embedded in the composite body structure)...the parts that cannot be repaired/replaced...what the subframes are attached to. those have to be strong and absolutely not allowed to corrode.
SAAB used galvanized subframes and they have performed very well around here.
My verdict on powder coating: nope. The least defect on the coating traps moisture below and the cancer grows almost faster than bare metal!
From my salt water experience, like pictured above, powder-coating will bubble, peel & rusts about as fast as any other paint. Anodized aluminum lasts pretty well, but still eventually corrodes, & is more subject to fatigue failure than any kind of steel. Stainless steel is ideal for longevity, & as you note, when optimized it can be cost-effective and also pretty light.
@philsfcs and @kiteboarder.. My team is in the middle of researching the total life cycle costs of mid-sized metal parts* out of 316 stainless steel vs anodized aluminum vs powder coated steel. My prediction is that stainless will win out when advanced 3D printing is used to minimize the amount of the stronger metal is needed.🧐I promise to post the results as soon as available.
*This would include parts like Aptera‘s front a-arms and rear swing arm. Maybe even the entire front tubular sub frame made in one piece.
@Tom Kruer , what is the assumed production numbers? I'm guessing the stamping & casting methods would become more cost-effective for larger production volume?
@Ken Kobayashi, lowering part costs at higher production rates requires ever increasing levels of Capital investment and lead times.
These costs were factored into the calculations above in an unbiased, and very simple way. Specifically, amortizing all capital equipment by each total Lifecycle hour required to make a part using each process.The bottom line is that AM built stainless steel seems to be the process to use for EV suspension components, regardless of production volume.
Northeast US: Oh, right. Some states still use salt, so ya, that's virtually a marine environment! I'm pretty sure one Aptera co-founder actually has a boat company, so that could be a good influence, & the car does seem easier than most to hose down the metal parts. Too bad about your neighbor's Ford, because now I guess you need to ask about corrosion control on every vehicle you buy! Sorry I can't help you more, but I've seen some computer images that others may be able to send.
It doesn't look like any of the discussion mentions the embedded parts (embedded in the composite body structure)...the parts that cannot be repaired/replaced...what the subframes are attached to. those have to be strong and absolutely not allowed to corrode.
SAAB used galvanized subframes and they have performed very well around here.
My verdict on powder coating: nope. The least defect on the coating traps moisture below and the cancer grows almost faster than bare metal!
From my salt water experience, like pictured above, powder-coating will bubble, peel & rusts about as fast as any other paint. Anodized aluminum lasts pretty well, but still eventually corrodes, & is more subject to fatigue failure than any kind of steel. Stainless steel is ideal for longevity, & as you note, when optimized it can be cost-effective and also pretty light.
@philsfcs and @kiteboarder.. My team is in the middle of researching the total life cycle costs of mid-sized metal parts* out of 316 stainless steel vs anodized aluminum vs powder coated steel. My prediction is that stainless will win out when advanced 3D printing is used to minimize the amount of the stronger metal is needed.🧐 I promise to post the results as soon as available.
*This would include parts like Aptera‘s front a-arms and rear swing arm. Maybe even the entire front tubular sub frame made in one piece.
Garaged all its life!
Northeast US: Oh, right. Some states still use salt, so ya, that's virtually a marine environment! I'm pretty sure one Aptera co-founder actually has a boat company, so that could be a good influence, & the car does seem easier than most to hose down the metal parts. Too bad about your neighbor's Ford, because now I guess you need to ask about corrosion control on every vehicle you buy! Sorry I can't help you more, but I've seen some computer images that others may be able to send.
Thanks, fixed it!
What are the embedded (into the composite structure) parts made of?
Marine environment: northeast US, the rust belt.
I have a neighbor with a 2002 Focus with 75000 miles with a completely rusted out rear subframe. A little galvanizing would have avoided that.
Are there any renderings or drawings of the various components?
I'm pretty sure the metal parts are aluminum. Ideally hard-anodized, but even just paint would be fine for non-marine environments.