Live data from Hacker News

A New Age of Materials Is Dawning, for Everything from Smartphones to Missiles

wsj.com

61–70 of 135 posts

Re: A New Age of Materials Is Dawning, for Everything from Smartphones to Missiles

#61

Nitpick time: > Modern composites, starting with Bakelite AFAIK Bakelite is a resin, not a composite. No mention of fiberglass, which had been used for many decades before carbon fiber went into widespread use. > composites—which are amalgamations of a variety of fibers, embedded in a variety of plastics Steel reinforced concrete is a composite and doesn’t fit this definition.

Also swear Bakelite is older than my grandpa, not sure it's exactly "modern"

Re: A New Age of Materials Is Dawning, for Everything from Smartphones to Missiles

#62
post #42

Why aren't more regular cars made of carbon fiber? Especially with EVs needing to be as efficient as possible. The BMW i3 had a carbon fiber frame and was still reasonably priced back in 2013, yet no other normal cars seem to have went this way.

Because it doesn't make a lot of sense to invest heavily into saving 100kg on the frame and then adding a 500kg battery. The i3 had a small, lighter battery and an extender.

Re: A New Age of Materials Is Dawning, for Everything from Smartphones to Missiles

#63

Earlier quoted context omitted.

I looked it up on Wikipedia ( https://en.wikipedia.org/wiki/Bakelite ) which said: > Because molded Bakelite incorporated fillers to give it strength, it tended to be made in concealing dark colors.[9]

In older style corded land line phones, the body was made of black bakelite, in India.

Same in Europe. In Cuba they where solid gold (joke reference to Scarface movie).

Re: A New Age of Materials Is Dawning, for Everything from Smartphones to Missiles

#64

Nitpick time: > Modern composites, starting with Bakelite AFAIK Bakelite is a resin, not a composite. No mention of fiberglass, which had been used for many decades before carbon fiber went into widespread use. > composites—which are amalgamations of a variety of fibers, embedded in a variety of plastics Steel reinforced concrete is a composite and doesn’t fit this definition.

Straw, sticks and mud composite walls. From before Mr. Christ was born.

Re: A New Age of Materials Is Dawning, for Everything from Smartphones to Missiles

#65

Were the soviets that far ahead? Because the T3 trams from the 60s were already made of composites.

You mean the Czechs. They also created the cloth/vinyl-clad microcars, the Velorex - https://en.wikipedia.org/wiki/Velorex

Re: A New Age of Materials Is Dawning, for Everything from Smartphones to Missiles

#66
post #60

Earlier quoted context omitted.

Parts of the DDR era Trabant cars were also made out of composites.

Papier-mache, to be exact. ;)

Afaik it wasn't paper mache, it was made of cotton fiber and used some kind of resin as a binding agent.

Paper uses wood pulp.

Re: A New Age of Materials Is Dawning, for Everything from Smartphones to Missiles

#67
post #62
post #42

Why aren't more regular cars made of carbon fiber? Especially with EVs needing to be as efficient as possible. The BMW i3 had a carbon fiber frame and was still reasonably priced back in 2013, yet no other normal cars seem to have went this way.

Because it doesn't make a lot of sense to invest heavily into saving 100kg on the frame and then adding a 500kg battery. The i3 had a small, lighter battery and an extender.

If your frame is 100kg lighter doesn’t that mean you can get even better mileage out of your battery? Or, for the same weight, fit even more battery?

Re: A New Age of Materials Is Dawning, for Everything from Smartphones to Missiles

#68
post #62

Earlier quoted context omitted.

Because it doesn't make a lot of sense to invest heavily into saving 100kg on the frame and then adding a 500kg battery. The i3 had a small, lighter battery and an extender.

If your frame is 100kg lighter doesn’t that mean you can get even better mileage out of your battery? Or, for the same weight, fit even more battery?

Yes, but is it cost-effective? Will the customer buy it?

Re: A New Age of Materials Is Dawning, for Everything from Smartphones to Missiles

#69

One of my biggest everyday QoL upgrade is men's casual pants finally getting elastane. E: not just elastane but performance fabrics from athleisure in general, good moisture/odour/temperature control, easy to maintain etc. Some people like break in into their cotton/denim classics, but performance fabrics tend to not need break in in at all.

Interesting that you should say that, because I'm of the exact opposite opinion. In fact, the omnipresence of elastane in pants has been a big QoL downgrade for me.

Re: A New Age of Materials Is Dawning, for Everything from Smartphones to Missiles

#70
So there are modern efforts to replace LP compressor blades of LM1500's (industrial conversions of J79's) to save weight and improve efficiency. Carbon fiber blades weigh a fraction of what metal ones do. Also, with computational fluid dynamics, new blade designs can be evolved and optimized for a specific power-band. For static applications, the risks of using more delicate materials can be tolerable if the efficiency in ROI exceeds service costs. There's a YT channel in Canada covering this development.
Post reply on HN