I don't doubt that Apple should take advantage of the US government's willingness to grant patents to them. The problem I was referring to is that the US patent office is out of control and is patenting things that are not "novel and nonobvious". Building a computer case out of an existing carbon fiber material is not novel or nonobvious.
I'm not really concerned about what those bloggers said. It's wrong, mostly.
But the patent system around the world has the same problems as the one here. So many patents are applied for that the offices are overwhelmed. It's been ages since the governments of any country have required working devices as evidence that a patent actually works; well, except for perpetual motion and energy machines.
And use DOES define whether a patent can be obtained. A new use can often get a patent granted. The obviousness quotient is used. Sure, people are always saying that something is obvious. But it's always obvious to them AFTER someone else does it. If the millions of engineers out there around the world don't think of something, but one or two guys come along and do, then it's not usually obvious. Give credit when it's due.
I think he's referring to high end racing yachts analogous to the Formula I racing cars. I believe America's Cup yachts all have carbon fiber incorporated in their hulls.
Yes, likely he is. Expense doesn't matter much there.
In aircraft at least, it's more about reducing parasitic drag and the ability to form complex aerodynamic shapes. Still, the aviation industry is very conservative. Cessna entered the light sport market with a riveted aluminum airplane even though everybody else is building them with composites, because it's what they know, and what they believe is widely accepted.
I would tend to disagree generally with your statement. If it was only about drag and aerodynamics, then I wouldn't have a job right now building carbon fiber structural members (under the skin) for the V-22, Blackhawk, Seahawk, BAMS and Globalhawk to mention a few. In fact, the BAMS decision was based on three things. Price, weight and stiffness. We were far superior in all 3 categories while we were competing with metallic competitors. Our closest competitor was 3X the cost, 2X the weight and 1/2 the stiffness. Carbon fiber is currently the best way to incorporate stiffness, strength and weight savings all in one package. The problem is that most people will dismiss it as too expensive without really checking into it, and mechanical engineers rarely change their opinion of materials even with glaring evidence.They only come to me when they can't figure out how to make their tin can meet ALL of their requirements like weight, strength, vibration, temperature etc.
The topic is about carbon fiber, its high tensile strength, low weight, and low thermal expansion. I did look up monocoque construction before I responded. How exactly is such structural design relevant to the goal of creating a more compact and "thinner" devices, like the iPad. I am not an engineer, so it would be enlightening if monocoques or semi-monocoques make sense towards this goal.
I don't happen to think this would be as rigid as a machines aluminum shell. You can't use monocoque construction because of the thickness, and the fact that it requires struts.
One of the reasons why Apple went with the aluminum was because they could do away with the supporting struts requires in all other designs. That limits how you can design the interior, as everything, has to be designed around those supports. with the CNC Al you don't need them for rigidity. Carbon fiber isn't nearly as rigid as this, and so as we can see from Apple's drawings, the shell needs to be much thicker.
As we get materials with lesser weight, they have to be thicker. Thus, aluminum needs to be thicker than steel, and plastic of all kinds needs to be thicker than aluminum. Carbon fiber is strong, but it flexes more.
The grade of carbon fiber sheet is also in question. I do some work with it. I have three one foot square samples 1mm thick here. One sheet costs $12.50. Another costs $43.00, and the last costs $126.00. Which do you think a manufacturer will use for a computing device case? Which do you think has the tightest weave with the greatest amount of carbon fiber as opposed to fill? Which do you think is the best?
I would tend to disagree generally with your statement. If it was only about drag and aerodynamics, then I wouldn't have a job right now building carbon fiber structural members (under the skin) for the V-22, Blackhawk, Seahawk, BAMS and Globalhawk to mention a few. In fact, the BAMS decision was based on three things. Price, weight and stiffness. We were far superior in all 3 categories while we were competing with metallic competitors. Our closest competitor was 3X the cost, 2X the weight and 1/2 the stiffness. Carbon fiber is currently the best way to incorporate stiffness, strength and weight savings all in one package. The problem is that most people will dismiss it as too expensive without really checking into it, and mechanical engineers rarely change their opinion of materials even with glaring evidence.They only come to me when they can't figure out how to make their tin can meet ALL of their requirements like weight, strength, vibration, temperature etc.
I agree with what you're saying, and in light of that, I'd also like to make it clear what I'm saying about stiffness.
Aluminum sheet isn't very stiff. I've built much from it over the decades. Carbon fiber is stiffer, in certain ways.
But Apple's devices, which is what we're supposed to be comparing things to, are made out of a stiff aluminum alloy, that is machined in a way that gives great stiffness that carbon fiber can't match without being made much thicker with supports internally. I imagine that those thick surrounding supports would do it as well, but do we really want such a bulky case?
I don't know. It's odd that with Apple going to thinner and thinner devices that they would step back to this.
Carbon Fiber sounds interesting. Only problem is that a metal back while adding extra weight also gives you that solid feeling when you hold it in your hand.
Interestingly, there is a technique for making carbon fibre panels exceptionally strong and rigid without the risk of breaking under stress.
The Shirley Institute in Manchester UK, developed a method of 3D weaving for the carbon fibre matting which is the basis for any carbon fibre panel. This was developed for Rolls Royce after they experienced major problems with carbon fibre fan blades used in jet engines. I don't see why Apple are trying to re-invent this particular wheel. The 3D solution works.
There goes all the recycling gains of Aluminum and glass!
The product is too heavy. It needs to be the same size, but lighter.
This is far more important than "recycling", as you imagine it. (because you do realize that just making them out of aluminum and glass does instantly = recycling? k)
Also, its pretty obvious that Apple is not going to produce anything that isn't at least as strong and durable as the current gen. If they can weave carbon fiber to be just as strong, half the weight, and half the price, then these are all very very good things.
If they can't get it quite right, you'll never hear about it again. Really quite that simple.
I would tend to disagree generally with your statement. If it was only about drag and aerodynamics, then I wouldn't have a job right now building carbon fiber structural members (under the skin) for the V-22, Blackhawk, Seahawk, BAMS and Globalhawk to mention a few. In fact, the BAMS decision was based on three things. Price, weight and stiffness. We were far superior in all 3 categories while we were competing with metallic competitors. Our closest competitor was 3X the cost, 2X the weight and 1/2 the stiffness. Carbon fiber is currently the best way to incorporate stiffness, strength and weight savings all in one package. The problem is that most people will dismiss it as too expensive without really checking into it, and mechanical engineers rarely change their opinion of materials even with glaring evidence.They only come to me when they can't figure out how to make their tin can meet ALL of their requirements like weight, strength, vibration, temperature etc.
THEY, were. Not "we". You work there, you don't own the place.
I would tend to disagree generally with your statement. If it was only about drag and aerodynamics, then I wouldn't have a job right now building carbon fiber structural members (under the skin) for the V-22, Blackhawk, Seahawk, BAMS and Globalhawk to mention a few. In fact, the BAMS decision was based on three things. Price, weight and stiffness. We were far superior in all 3 categories while we were competing with metallic competitors. Our closest competitor was 3X the cost, 2X the weight and 1/2 the stiffness. Carbon fiber is currently the best way to incorporate stiffness, strength and weight savings all in one package. The problem is that most people will dismiss it as too expensive without really checking into it, and mechanical engineers rarely change their opinion of materials even with glaring evidence.They only come to me when they can't figure out how to make their tin can meet ALL of their requirements like weight, strength, vibration, temperature etc.
I see your point, but I'm talking only about attitudes within general aviation, which are very different than commercial or military. If I buy another airplane I'd prefer one made of composites, but if you talk to general aviation A&Ps or old-timer pilots, they'll urge you to stick with the tried-and-true. A significant part the general aviation industry (Cessna, in particular) has stuck with riveted aluminum because these attitudes are so slow to change.
...A significant part the general aviation industry (Cessna, in particular) has stuck with riveted aluminum because these attitudes are so slow to change.
And 1930's engine technology. Check those magnetos...
And 1930's engine technology. Check those magnetos...
Let's understand something here. Most aircraft are still made from aluminum, both large and small. Carbon fiber is NOT an ideal material. It has its own problems. One major one is manufacturing defects. Just ask Boeing and Airbus.
And 1930's engine technology. Check those magnetos...
Older than that, really. You'll find magnetos in cars from the 1910s. Actually, there's a logic behind the persistence of this primitive ignition systems in airplanes. Magnetos don't require an electrical system. It's nice to know that an electrical failure won't cause the engine to stop running.
Quote:
Originally Posted by melgross
Let's understand something here. Most aircraft are still made from aluminum, both large and small. Carbon fiber is NOT an ideal material. It has its own problems. One major one is manufacturing defects. Just ask Boeing and Airbus.
Many, but I'm not sure about most. An awful lot of the newest general aviation airplanes coming on the market are all composite, and they are not a source of problems so far as I have heard. A conspicuous holdout is Cessna, but you have to know that they are extremely conservative and always have been. Some of the few times they've moved away from what they know works, and what their customers expect, they've been burned.
Many, but I'm not sure about most. An awful lot of the newest general aviation airplanes coming on the market are all composite, and they are not a source of problems so far as I have heard. A conspicuous holdout is Cessna, but you have to know that they are extremely conservative and always have been. Some of the few times they've moved away from what they know works, and what their customers expect, they've been burned.
While more new planes are being made from composite, most that are being made now are still made from aluminum.
While more new planes are being made from composite, most that are being made now are still made from aluminum.
On a semi related topic, NOVA did a great jobs with Battle of the X-Planes. One thing I recall is the complexity of the CF that Boeing was trying to use which is one reason the Lockheed jet ended up winning the contract.
edit: Since this thread is older I’m going to post a fairly long snippet from the show’s transcript. If it’s too much, just let me know and I’ll remove it.
NARRATOR: The frame for the single massive delta wing, the heart of the Boeing design, is already in the works. But the skin that will cover it is being cooked up over a thousand miles away at Boeing's headquarters in Seattle.
Engineer George Bible has spent the last year experimenting with a revolutionary material for the surface of the wings. It's a resin and carbon fiber mix called "thermoplastic." In small quantities, it's been used on fighters before, but no one has ever tried to create anything as large as a 30-foot wing skin.
GEORGE BIBLE (Manufacturing Engineer, The Boeing Company): It's very challenging. We have no time or schedule to design something else, so we, we have to make it work the first shot.
NARRATOR: Thermoplastic wings will be lighter and more durable than conventional wings. There may even be other undiscovered benefits, according to another engineer who first experimented with the material in the '80s, Frank Statkus.
FRANK STATKUS: I personally would love to have thermoplastics on this airplane, because I know that there's value in the future. Even though I can't tell you in all the areas where we might find that value, I do know it's there.
NARRATOR: The future in a word: thermoplastics.
But right now, George Bible needs to solve some pressing problems. Making thermoplastic begins with these sheets of graphite, also known as carbon fiber, the same lightweight material used in fishing rods and tennis rackets. For the wing, it's laid down up to 90 layers deep on top of a giant metal mold or tool.
GEORGE BIBLE:\tWe take layers of these graphite fibers and set them on top of each other, and then we put the resin in between to hold them together.
NARRATOR: After three weeks of lay-up, the wing skin is tightly wrapped in protective bags, ready for the next step, a massive oven called the autoclave. The huge chamber acts like a pressure cooker.
GEORGE BIBLE: The autoclave, for me, is always the most stressful part. You have nightmares at night thinking about all of the terrible things your autoclave could do to it.
NARRATOR: First, all oxygen will be removed to prevent a cataclysmic explosion. Then, with the wing heated to the melting point of lead, nitrogen will be pumped in, raising the pressure and exerting tons of force upon the thermoplastic, forcing the fibers to blend with the resin. In short, this is literally hell on earth.
For the next 30 hours, George Bible will hold his breath, until the cooked skin from the autoclave and a perfectly formed wing skin is revealed.
GEORGE BIBLE:\tOh, she looks beautiful doesn't she? Looks good, looks very good.
NARRATOR: But this skin is only the first. Boeing will need three more, one for each side of its two delta-winged X-planes. And although Bible is elated at his success, he knows that the next skin, for the lower wing, will be far trickier. It involves a more complex curved shape.
And, in fact, when the next skin emerges from the autoclave, the first signs are ominous. Creases and folds on the surface hint at hidden structural flaws.
GEORGE BIBLE:\tMan, that does not look good, those wrinkles. I'm afraid we're dead in the water.
NARRATOR: An instrument scans the surface of the panel using water and sound waves to probe for air pockets that could fatally weaken the wing.
GEORGE BIBLE:\tWhen we have a gap in the plies, the sound will not transmit through there well.
NARRATOR: George Bible's worst fears are confirmed. The skin is riddled with defects.
GEORGE BIBLE:\tRight now I'm just, just exhausted. We can't get a break, I mean it's just downhill. So we'll have to do what we have to do to get a panel down to Palmdale as fast as we can.
NARRATOR: After hundreds of hours of work, the wing skin is worthless. With the first wing frame nearing completion down in Palmdale, Bible's team and its bold experiment are simply running out of time.
Even if you can cut any one of the heaviest items in half, it really doesn't significantly cut the weight of the product.
Quote:
Originally Posted by cnocbui
Carbon is not exactly in short supply. There are CF recovery systems if we start to run short.
It's not the carbon part that's a worry, the resin isn't recyclable that I've heard.
Quote:
Originally Posted by stevetim
I hate carbon fiber. Hope apple continues with their present materials.
Quote:
Originally Posted by Joe hs
No, I feel exactly the same way.
Any particular reason for the hate?
I'm not convinced that it's something Apple is going to use on their own products.
Quote:
Originally Posted by Dr Millmoss
Entire airplanes are now made of carbon fiber, and have been for many years now -- in general aviation at least. The long-term durability of these airframes, particularly considering exposure to sun, is still a question, but then the durability of aluminum airframes has exceeded anyone's expectations.
The Starship has been flying since 1986, that's 25 years now. Not a lot were made, but I'd think that should help build a track record.
Quote:
Originally Posted by oseame
The combustion point of any magnesium alloy that finds it's way in to a laptop would be higher than the temps found in a battery fire
check out the HP Envy for a mg alloy laptop in production
Haven't Thinkpads been made using magnesium in their shells for quite some time? Seems like they've been doing it forever. I'm pretty sure Apple used some magnesium parts in their chassis before the unibodies.
Comments
I don't doubt that Apple should take advantage of the US government's willingness to grant patents to them. The problem I was referring to is that the US patent office is out of control and is patenting things that are not "novel and nonobvious". Building a computer case out of an existing carbon fiber material is not novel or nonobvious.
http://www.bloggersbase.com/computer...-fiber-laptop/
http://www.google.com/search?client=...er+laptop+body
I'm not really concerned about what those bloggers said. It's wrong, mostly.
But the patent system around the world has the same problems as the one here. So many patents are applied for that the offices are overwhelmed. It's been ages since the governments of any country have required working devices as evidence that a patent actually works; well, except for perpetual motion and energy machines.
And use DOES define whether a patent can be obtained. A new use can often get a patent granted. The obviousness quotient is used. Sure, people are always saying that something is obvious. But it's always obvious to them AFTER someone else does it. If the millions of engineers out there around the world don't think of something, but one or two guys come along and do, then it's not usually obvious. Give credit when it's due.
Yeah!
Who's your Daddy?
.
I am. Wanna make somethin of it?
I think he's referring to high end racing yachts analogous to the Formula I racing cars. I believe America's Cup yachts all have carbon fiber incorporated in their hulls.
Yes, likely he is. Expense doesn't matter much there.
In aircraft at least, it's more about reducing parasitic drag and the ability to form complex aerodynamic shapes. Still, the aviation industry is very conservative. Cessna entered the light sport market with a riveted aluminum airplane even though everybody else is building them with composites, because it's what they know, and what they believe is widely accepted.
I would tend to disagree generally with your statement. If it was only about drag and aerodynamics, then I wouldn't have a job right now building carbon fiber structural members (under the skin) for the V-22, Blackhawk, Seahawk, BAMS and Globalhawk to mention a few. In fact, the BAMS decision was based on three things. Price, weight and stiffness. We were far superior in all 3 categories while we were competing with metallic competitors. Our closest competitor was 3X the cost, 2X the weight and 1/2 the stiffness. Carbon fiber is currently the best way to incorporate stiffness, strength and weight savings all in one package. The problem is that most people will dismiss it as too expensive without really checking into it, and mechanical engineers rarely change their opinion of materials even with glaring evidence.They only come to me when they can't figure out how to make their tin can meet ALL of their requirements like weight, strength, vibration, temperature etc.
The topic is about carbon fiber, its high tensile strength, low weight, and low thermal expansion. I did look up monocoque construction before I responded. How exactly is such structural design relevant to the goal of creating a more compact and "thinner" devices, like the iPad. I am not an engineer, so it would be enlightening if monocoques or semi-monocoques make sense towards this goal.
I don't happen to think this would be as rigid as a machines aluminum shell. You can't use monocoque construction because of the thickness, and the fact that it requires struts.
One of the reasons why Apple went with the aluminum was because they could do away with the supporting struts requires in all other designs. That limits how you can design the interior, as everything, has to be designed around those supports. with the CNC Al you don't need them for rigidity. Carbon fiber isn't nearly as rigid as this, and so as we can see from Apple's drawings, the shell needs to be much thicker.
As we get materials with lesser weight, they have to be thicker. Thus, aluminum needs to be thicker than steel, and plastic of all kinds needs to be thicker than aluminum. Carbon fiber is strong, but it flexes more.
The grade of carbon fiber sheet is also in question. I do some work with it. I have three one foot square samples 1mm thick here. One sheet costs $12.50. Another costs $43.00, and the last costs $126.00. Which do you think a manufacturer will use for a computing device case? Which do you think has the tightest weave with the greatest amount of carbon fiber as opposed to fill? Which do you think is the best?
I would tend to disagree generally with your statement. If it was only about drag and aerodynamics, then I wouldn't have a job right now building carbon fiber structural members (under the skin) for the V-22, Blackhawk, Seahawk, BAMS and Globalhawk to mention a few. In fact, the BAMS decision was based on three things. Price, weight and stiffness. We were far superior in all 3 categories while we were competing with metallic competitors. Our closest competitor was 3X the cost, 2X the weight and 1/2 the stiffness. Carbon fiber is currently the best way to incorporate stiffness, strength and weight savings all in one package. The problem is that most people will dismiss it as too expensive without really checking into it, and mechanical engineers rarely change their opinion of materials even with glaring evidence.They only come to me when they can't figure out how to make their tin can meet ALL of their requirements like weight, strength, vibration, temperature etc.
I agree with what you're saying, and in light of that, I'd also like to make it clear what I'm saying about stiffness.
Aluminum sheet isn't very stiff. I've built much from it over the decades. Carbon fiber is stiffer, in certain ways.
But Apple's devices, which is what we're supposed to be comparing things to, are made out of a stiff aluminum alloy, that is machined in a way that gives great stiffness that carbon fiber can't match without being made much thicker with supports internally. I imagine that those thick surrounding supports would do it as well, but do we really want such a bulky case?
I don't know. It's odd that with Apple going to thinner and thinner devices that they would step back to this.
Magnesium or a heavy rubber may be the answer.
A battery fire in a Mg framed laptop may be very interesting indeed.
The combustion point of any magnesium alloy that finds it's way in to a laptop would be higher than the temps found in a battery fire
check out the HP Envy for a mg alloy laptop in production
The Shirley Institute in Manchester UK, developed a method of 3D weaving for the carbon fibre matting which is the basis for any carbon fibre panel. This was developed for Rolls Royce after they experienced major problems with carbon fibre fan blades used in jet engines. I don't see why Apple are trying to re-invent this particular wheel. The 3D solution works.
There goes all the recycling gains of Aluminum and glass!
The product is too heavy. It needs to be the same size, but lighter.
This is far more important than "recycling", as you imagine it. (because you do realize that just making them out of aluminum and glass does instantly = recycling? k)
If they can't get it quite right, you'll never hear about it again. Really quite that simple.
I would tend to disagree generally with your statement. If it was only about drag and aerodynamics, then I wouldn't have a job right now building carbon fiber structural members (under the skin) for the V-22, Blackhawk, Seahawk, BAMS and Globalhawk to mention a few. In fact, the BAMS decision was based on three things. Price, weight and stiffness. We were far superior in all 3 categories while we were competing with metallic competitors. Our closest competitor was 3X the cost, 2X the weight and 1/2 the stiffness. Carbon fiber is currently the best way to incorporate stiffness, strength and weight savings all in one package. The problem is that most people will dismiss it as too expensive without really checking into it, and mechanical engineers rarely change their opinion of materials even with glaring evidence.They only come to me when they can't figure out how to make their tin can meet ALL of their requirements like weight, strength, vibration, temperature etc.
THEY, were. Not "we". You work there, you don't own the place.
I would tend to disagree generally with your statement. If it was only about drag and aerodynamics, then I wouldn't have a job right now building carbon fiber structural members (under the skin) for the V-22, Blackhawk, Seahawk, BAMS and Globalhawk to mention a few. In fact, the BAMS decision was based on three things. Price, weight and stiffness. We were far superior in all 3 categories while we were competing with metallic competitors. Our closest competitor was 3X the cost, 2X the weight and 1/2 the stiffness. Carbon fiber is currently the best way to incorporate stiffness, strength and weight savings all in one package. The problem is that most people will dismiss it as too expensive without really checking into it, and mechanical engineers rarely change their opinion of materials even with glaring evidence.They only come to me when they can't figure out how to make their tin can meet ALL of their requirements like weight, strength, vibration, temperature etc.
I see your point, but I'm talking only about attitudes within general aviation, which are very different than commercial or military. If I buy another airplane I'd prefer one made of composites, but if you talk to general aviation A&Ps or old-timer pilots, they'll urge you to stick with the tried-and-true. A significant part the general aviation industry (Cessna, in particular) has stuck with riveted aluminum because these attitudes are so slow to change.
...A significant part the general aviation industry (Cessna, in particular) has stuck with riveted aluminum because these attitudes are so slow to change.
And 1930's engine technology. Check those magnetos...
And 1930's engine technology. Check those magnetos...
Let's understand something here. Most aircraft are still made from aluminum, both large and small. Carbon fiber is NOT an ideal material. It has its own problems. One major one is manufacturing defects. Just ask Boeing and Airbus.
And 1930's engine technology. Check those magnetos...
Older than that, really. You'll find magnetos in cars from the 1910s. Actually, there's a logic behind the persistence of this primitive ignition systems in airplanes. Magnetos don't require an electrical system. It's nice to know that an electrical failure won't cause the engine to stop running.
Let's understand something here. Most aircraft are still made from aluminum, both large and small. Carbon fiber is NOT an ideal material. It has its own problems. One major one is manufacturing defects. Just ask Boeing and Airbus.
Many, but I'm not sure about most. An awful lot of the newest general aviation airplanes coming on the market are all composite, and they are not a source of problems so far as I have heard. A conspicuous holdout is Cessna, but you have to know that they are extremely conservative and always have been. Some of the few times they've moved away from what they know works, and what their customers expect, they've been burned.
Many, but I'm not sure about most. An awful lot of the newest general aviation airplanes coming on the market are all composite, and they are not a source of problems so far as I have heard. A conspicuous holdout is Cessna, but you have to know that they are extremely conservative and always have been. Some of the few times they've moved away from what they know works, and what their customers expect, they've been burned.
While more new planes are being made from composite, most that are being made now are still made from aluminum.
While more new planes are being made from composite, most that are being made now are still made from aluminum.
On a semi related topic, NOVA did a great jobs with Battle of the X-Planes. One thing I recall is the complexity of the CF that Boeing was trying to use which is one reason the Lockheed jet ended up winning the contract.
edit: Since this thread is older I’m going to post a fairly long snippet from the show’s transcript. If it’s too much, just let me know and I’ll remove it.
Am I the only one who dislikes carbon fiber and adores aluminum and glass?
Btw, I really think the weight issue is more a battery tec issue than anything else...
That's what I thought, but it's still a factor.
Here's the weight breakdown: Aluminum back: 138 grams, Battery: 148 grams, LCD: 153 grams, Glass (and frame): 193 grams, Speaker: 17 grams, Main board: 21 grams, Everything else: 27 grams
http://www.ifixit.com/Teardown/iPad-...eardown/2183/4
Even if you can cut any one of the heaviest items in half, it really doesn't significantly cut the weight of the product.
Carbon is not exactly in short supply. There are CF recovery systems if we start to run short.
It's not the carbon part that's a worry, the resin isn't recyclable that I've heard.
I hate carbon fiber. Hope apple continues with their present materials.
No, I feel exactly the same way.
Any particular reason for the hate?
I'm not convinced that it's something Apple is going to use on their own products.
Entire airplanes are now made of carbon fiber, and have been for many years now -- in general aviation at least. The long-term durability of these airframes, particularly considering exposure to sun, is still a question, but then the durability of aluminum airframes has exceeded anyone's expectations.
The Starship has been flying since 1986, that's 25 years now. Not a lot were made, but I'd think that should help build a track record.
The combustion point of any magnesium alloy that finds it's way in to a laptop would be higher than the temps found in a battery fire
check out the HP Envy for a mg alloy laptop in production
Haven't Thinkpads been made using magnesium in their shells for quite some time? Seems like they've been doing it forever. I'm pretty sure Apple used some magnesium parts in their chassis before the unibodies.
While more new planes are being made from composite, most that are being made now are still made from aluminum.
I don't know where you are getting this information, but I repeat again that I am referring to general aviation, not all airplanes.