03-20-2013, 08:01 PM | #141 |
Drives: 2011 2SS/RS LS3 Join Date: Nov 2011
Location: Torrance
Posts: 14,466
|
|
03-20-2013, 08:42 PM | #142 | |
Account Suspended
Drives: 2010 Camaro 2SS/RS Join Date: Apr 2008
Location: New York
Posts: 3,746
|
Quote:
FYI, a candle burns at 1000 °C, which is more than enough to get magnesium started. The only thing that extra mass gives you is it can dissipate a small heat source like a candle, which prevents it from igniting, as the large mass takes a large heat source to get it hot enough (swap in a gasoline fire, or oil fire instead of a candle and you have a large source). However, a magnesium engine block is already warmed up by the running engine, and if you have certain engine failures or lose oil pressure, the friction of the moving parts is more than enough to ignite the block. There is a history of this in the old VW Beetle boxer engine, which was made from a magnesium alloy. Back when they were common, firefighters were offered training on how to fight a Beetle fire, because magnesium reacts with water forming magnesium oxide and hydrogen and so using a fire hose on the beetle could create a hydrogen cloud which essentially explodes. A CO2 fire extinguisher is also useless on a Beetle fire because it will readily burn in a CO2 atmosphere, forming magnesium oxide and carbon. The way they said to deal with a Beetle engine fire was to shovel dirt on it to snuff it out. Usually, once going the firefighters would just stand back and allow the car to be consumed by the fire. If you guys a big fans of magnesium bodied cars, I suggest you look up the F1 racing Honda RA302, which crashed in lap 2 of the 1968 French Gran Prix and the body caught fire and could not be extinguished. Magnesium is not to be trifled with. I'm not looking forward to paying a lot more money for a car that doesn't save as much money in fuel as the additional cost to buy, plus is made from a very flammable element that makes it even less safe. |
|
03-20-2013, 08:46 PM | #143 |
I used to be Dragoneye...
|
I'm confused....I thought they referred to their new Aluminum welding procedure...making aluminum the near-term "super material" for weight savings...why the focus on magnesium in here?
|
03-20-2013, 08:46 PM | #144 |
Hail to the King baby!
Drives: '19 XT4 2.0T & '22 VW Atlas 2.0T Join Date: Dec 2008
Location: Illinois
Posts: 12,215
|
Boy sure love the magnesium cradle in the Z06. Haven't seen one burst into flames yet, though.
__________________
"Speed, it seems to me, provides the one genuinely modern pleasure." - Aldous Huxley
|
03-20-2013, 08:51 PM | #145 |
Drives: Camaro's, always have, always will. Join Date: Oct 2010
Location: Home of the brave
Posts: 4,851
|
...Ok Capitain, spell it out....where is the irony? Inquiring minds wanna know....
__________________
In Scott We Trust...all others must show proof.
|
03-20-2013, 08:56 PM | #146 | |
Hail to the King baby!
Drives: '19 XT4 2.0T & '22 VW Atlas 2.0T Join Date: Dec 2008
Location: Illinois
Posts: 12,215
|
Quote:
But even aluminium costs a big bunch more than steel. Waiting for unobtanium to reach a higher threshold for usage driving cost even lower.
__________________
"Speed, it seems to me, provides the one genuinely modern pleasure." - Aldous Huxley
|
|
03-20-2013, 08:58 PM | #147 |
I used to be Dragoneye...
|
Is magnesium even as malleable as aluminum for stamping? And aluminum wins no awards in that respect, either...
|
03-20-2013, 09:05 PM | #148 | |
Drives: 2011 2SS/RS LS3 Join Date: Nov 2011
Location: Torrance
Posts: 14,466
|
Quote:
Cheap, mushy aluminum won't stamp or bend with any quality, either...It's a balancing act...Aircraft alumunum is high quality, hi-grade aluminum... ...Anything can be done, just the process requires more engineering... |
|
03-20-2013, 09:05 PM | #149 |
Drives: Camaro's, always have, always will. Join Date: Oct 2010
Location: Home of the brave
Posts: 4,851
|
...then I guess you are out, and then we will be for the better if you find a happier place, no?
__________________
In Scott We Trust...all others must show proof.
|
03-20-2013, 09:49 PM | #150 | |
I used to be Dragoneye...
|
Quote:
I've been reading up (what I can in the past 45 minutes). Apparently, you can add rare earth metals into the alloy formula, and this changes the properties of (among other things) the ignition temperature of the material. Since Al-Mg alloys don't burn at the same temperatures as pure Mg to begin with...Alloys with the intent of high-temperature applications can be formed by using this technique. The Corvette's Mg engine cradle is made out of a special alloy; AE44. And it caught some press in the engineering community for it's ability to perform in high-temperature situations. Was the first application of its kind, apparently. Nothing's perfect, obviously. Imagine if the electric car had taken off in the early 1900s and we were driving developed versions of them today....and then someone came along and suggested we switch to this cheap, and high-energy liquid fuel: "Gas-O-Leen"....I imagine there'd have been an uproar over endangering the driving public by making them drive around with a flammable/combustable/explosive material sloshing around in tanks underneath the cars. With all that said: I look forward to seeing how GM intends to carry out this goal of 15% weight reduction. No doubt they've done some research on the subject to back up the number (or at least come close) with results. I've never heard them be so specific without knowing they can do it, first. If it happens to be Mg...Hey - as long as it won't rust when the paint's chipped after years of driving, count me in. |
|
03-20-2013, 10:01 PM | #151 |
Drives: 2011 2SS/RS LS3 Join Date: Nov 2011
Location: Torrance
Posts: 14,466
|
...Just for drill, I'd say the more you look at aircraft, or even NASA (lol), if the technology gets put into cars...all the better....
As for safety....it's the manufacturing, machining and fabricating where you gotta be careful with magnesium...it is a different animal...By the time it gets to the cars, though, no worries... As far as fires in cars and health and safety, there's bigger fish to fry with plastics, composites, and batteries than with aluminum and magnesium...lol... |
03-20-2013, 11:40 PM | #152 | |
Account Suspended
Drives: 2010 Camaro 2SS/RS Join Date: Apr 2008
Location: New York
Posts: 3,746
|
Quote:
With all this talk about 15% weight reduction, this looks like the obvious solution, because it follows precedent set over many years: reduce weight by using more expensive materials that reduce reliability and passenger safety. USA Today did a really good article a while back explaining the human price paid for forced Fuel Economy standards. Considering the leanings of the source publication, the credibility of the research cannot be dismissed to bias. I hope this is allowable discussion here. I'm completely serious. |
|
03-20-2013, 11:43 PM | #153 |
Account Suspended
Drives: 2010 Camaro 2SS/RS Join Date: Apr 2008
Location: New York
Posts: 3,746
|
|
03-20-2013, 11:48 PM | #154 | |
Account Suspended
Drives: 2010 Camaro 2SS/RS Join Date: Apr 2008
Location: New York
Posts: 3,746
|
Quote:
The vast majority of rare earths are now being mined by Chinese firms, who control the price because they have the market cornered. This topic contains my daily recommended allowance of irony. |
|
|
|
Post Reply
|
|
|