Surface Pro 3 Heat

[RémiM]

I believe the aluminum-magnesium alloy used for the SP3 doesnt have the eutectic composition. The melting point is certainly much higher than 342C.

Let them believe their SP3 is made out of chocolate.

 

[Haldi]

The lowest possible melting point of a eutectic magnesium alloy is 342c or 648f.

Which absolutly doesn't matter! Because in this case here we don't want to meld a Surface 3 we want to bend a Surface 3!
And as we now all know you can easily bend a iPhone 6! Even tough it's cold.

So ? Do we have a force on our surface 3 or are we just calculating the bend trough expansion due temperature? Let's use later...

What alloy do we have on our Surface 3 ? Magnesium only ? Magnesium Aluminum? Magnesium Zinc ? Doesn't matter. Thermal expansion coeffcient is about 26x10^-6/Kelvin
Meaning the length of 292,2mm changing from 20°C to 47°C will increase in length by 0,20512mm!
Is this enough to bend? No idea!

 

[RémiM]

Well, we have debated this a lot. Maybe too much.

The melting temperature is important if you consider that some deformation systems occure easily at 1/2 of the melting point.

We all agree that the poor 75-90°C generated by the proc wont do anything. Even if there are some residual stresses from the manufacturing process.

Let's eat chocolate. It melts at low temp and it tastes good.

 

[GreyFox7]

I believe the aluminum-magnesium alloy used for the SP3 doesnt have the eutectic composition. The melting point is certainly much higher than 342C.

Let them believe their SP3 is made out of chocolate.

Indeed, and that was the lowest possible Alloy. I'm not aware of the exact mixture so I chose the absolute minimum eutectic alloy to give the maximum benefit of doubt. Eutectic Mg-Al alloy melting point is 819f/437c. it wouldn't be unrealistic to assume greater than 500c. I once heard there was also copper in the alloy to increase the thermal heat transfer which would also raise the melt point.

Which absolutly doesn't matter! Because in this case here we don't want to meld a Surface 3 we want to bend a Surface 3!
And as we now all know you can easily bend a iPhone 6! Even tough it's cold.

So ? Do we have a force on our surface 3 or are we just calculating the bend trough expansion due temperature? Let's use later...

What alloy do we have on our Surface 3 ? Magnesium only ? Magnesium Aluminum? Magnesium Zinc ? Doesn't matter. Thermal expansion coeffcient is about 26x10^-6/Kelvin
Meaning the length of 292,2mm changing from 20°C to 47°C will increase in length by 0,20512mm!
Is this enough to bend? No idea!

What from any of that would lead one to conclude a mere 45c case temperature would amount to a micron mole hills difference. Good Lord the education system has completely failed.

 

[RémiM]

Thermal expansion coeffcient is about 26x10^-6/Kelvin
Meaning the length of 292,2mm changing from 20°C to 47°C will increase in length by 0,20512mm!
Is this enough to bend? No idea!

It's wrong to only consider one coefficient of expansion.

The device is made of a lot of materials and more than 1 coefficient of expansion are involved when the device warms up.

The screen for example doesnt deform a lot with heat, and then it creates tension stresses on the chassis when the latter wants to expand.

But well, it's nothing, and it wont bend the SP3.

 

[RémiM]

I once heard there was also copper in the alloy to increase the thermal heat transfer which would also raise the melt point.

With aluminum, copper creates Al2Cu particles, wich are very good at high temprature. There are much more stable than other type of particles (Mg2Si for instance) and help a lot to keep the material "harder" during a much longer long time.

In the automotive industry, we rely a lot on these precipitates to make your engine work until 300000 km. Particularly the cylinder heads, which are made out of Al-Si-Cu-Mg alloys. Most of the time the are also heat treated to ensure the best mechanical properties.

And it's also true that copper increases the thermal heat transfer but it makes the alloy more sensitive to corrosion.

 

[jnjroach]

According to my contacts on the Surface Team who is responsible for overseeing the released product, any actual bend in the Surface Pro 3 is due to a manufacturing defect of the particular device and should be exchanged, they are not bending over time....

 

[GreyFox7]

With aluminum, copper creates Al2Cu particles, wich are very good at high temprature. There are much more stable than other type of particles (Mg2Si for instance) and help a lot to keep the material "harder" during a much longer long time.

In the automotive industry, we rely a lot on these precipitates to make your engine work until 300000 km. Particularly the cylinder heads, which are made out of Al-Si-Cu-Mg alloys. Most of the time the are also heat treated to ensure the best mechanical properties.

And it's also true that copper increases the thermal heat transfer but it makes the alloy more sensitive to corrosion.

Oh you've done it now.. the corrosion angle will be next...
I spilled OJ or tomato sauce on my Surface and it corroded, run for the hills

 

[Haldi]

There are exactly 2 pieces to consider.
A: The Magnesium case
B: the Screen
All other parts inside are placed/mounted with enough space to work fine trough all temperatur ranges.
the 0.2mm are from the center of the case (which is thinner) to the edge/borders (which are thicker and therefore stay colder for longer)
But this is not entierly correct as the heat is in a circle around the CPU therefore it wouldn't even expand by 0.2mm...
To really calculate the energy buildup trough heat you'd need the case in 3d and simulate it.
But as you said before, there is litteraly no chance the 0.2mm in length could bend it in a visible way!

So people claim their Surface 3 bends.... HOW ? there are only 2 possible ways... A: a mechanical force from outside B: Heat from inside.
Are there any other ways you can think of? i can't!
So the heat alone does not.
And the combined way of heat and mechanical force from the own weight is absolutly ludicrous because you would need to lift your surface from corner to get remotley enough force to even start thinking about bending.

 

[RémiM]

Oh you've done it now.. the corrosion angle will be next...
I spilled OJ or tomato sauce on my Surface and it corroded, run for the hills

I will try to mouth wash with OJ after brushing my teeth and then spit on my SP3. I'll tell you what it does