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Comment by Tharkun | Hacker News Reader

Pardon the tangent, but here's a quote from their website:

> There’s a reason titanium is used to build rockets and replace bones. Unlike aluminum, which is what most phones are made of, titanium doesn’t scratch, dent, or bend.

The reason why titanium is used to replace bones is not its strength (though it certainly doesn't hurt). It's because titanium is the most biocompatible metal and has a capacity for osseointegration. Meaning the bone around it will fuse with the titanium.

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And titanium does scratch, dent, and bend. Just not to the extent of aluminum. I'm looking at a titanium hammer right now.

But we can't let science get in the way of marketing copy, now can we?

(Thanks for the interesting tangent, btw)

And especially because of its flexibility (Young's modulus) - which is very similar to the bones' ones. That's why Ti alloys are preferred when a prosthesis needs to be anchored into a bone, like the stem part of a hip implant.

Talk about lock in...

When mac books needed some pep in marketing, as sales floundered, Jobs also diverged into Titanium in lieu of faster uPs. After that wore off he went to the unwieldy 17" Mac Books.

Often times Titanium is just a marketing ploy. Like titanium cards. Titanium bracelets. Etc.

And Apple moved to using aluminum from titanium in its PowerBooks (the design would later be the basis of the original MacBook Pro), in part, because the softness of of the metal, led to warps and bends in those first-gen TiBook models. I don't know how Essential is using titanium, but history certainly has examples of gadgets that suffered from using that metal over others.

The Ti-Books had a lot of issues. The biggest one was broken hinges. There were a lot of physical problems with those machines that didn't manifest until after about a year's worth of use.

Too bad, they were really cool at the time they were introduced.

...and if you believe that, I've got a bridge for sale. Titanium is many things but soft it is not. It can also be alloyed with many other metals for specific purposes. One thing it definitely is though is expensive which is most likely the reason for Apple to look for alternatives. That is actually is possible to use titanium to create form-stable notebooks can be seen by e.g. the many Thinkpads which sport titanium lids and frames. I have yet to see one of these warped or bent. This is partly due to the boxy - and with that, strong - form factor but the material plays a big role as well.

The failure mode I observed most frequently in the TiBooks case was the titanium would crack, particularly around the edges.

Titanium is also a relatively poor conductor of heat. Aluminum conducts heat over 10 times better than Titanium. Use of aluminium would be much better at conducting heat away from the body of the notebook.

Thinkpads generally use magnesium frames, not titanium.

https://forums.lenovo.com/t5/ThinkPad-T400-T500-and-newer-T/...

For anyone wanting to brighten their day with some thinkpads, it unfortunately looks like large chunks of magnesium are not flammable [1].

[1] http://www.fishercast.com/downloads/FisherCast_Magnesium_Whi...

No, Mg is used for alloyed aircraft wheels, so I'm sure its not like Mn.

The T-series (at least from T2x to T6x) had titanium lids. I don't know what they use nowadays as I am in the habit of using older machines (currently using a T42p with 1600x1200 4:3 screen). The T21 I'm using as a mobile terminal to access headless servers has been used as a seat cushion more than once, the screen hasn't budged...

http://www.thinkwiki.org/wiki/ThinkPad_series

Ti is about 3x as hard as Al:

https://en.wikipedia.org/wiki/Hardnesses_of_the_elements_(da...

Not to mention, very few use pure titanium. Most use an alloy like 6al4v, which gives it the best of both worlds.

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