2 HN users recommended this explainer2 months2025–2026score 2.5
Years with an HN recommendation, 2007–2026
Commenters send it to people asking how engines survive such temperatures, and call it fascinating and worth watching.
Veritasium explains how jet engines run hotter than their components' melting points, using cooling air and single-crystal superalloy turbine blades. It covers how the blades are grown as aligned crystals.
“is absolutely fascinating & well worth a watch” (HN, 2026)
The Veritasium video on how jet engine turbine blades are "grown" in an aligned crystalline structure for enhanced material properties (e.g. thermal performance) is absolutely fascinating & well worth a watch: [this video]
How turbine blades are grown as aligned single crystals
I know Veritasium gets posted here a lot, but a few days ago he posted a deep-dive into the the engineering of jet engine turbine blades. Turns out they're made from a single crystal of a superalloy that entangles itself at a molecular level such that it actually gains strength as it's heated, only losing strength above 1200 degrees C / 2200 degrees F. Below that temperature, as long as the strain on the part is below the plastic deformation threshold, it's not really losing any strength at all over time. [this video]
Deep dive into single-crystal superalloy turbine blade engineering
> Power generation turbines are designed to work at ambient sea level conditions. They don't rely on ambient air being especially cold for cooling, they can keep cool thanks to the large mass flow rate What could be contributing to this is recently Vertasium did a whole video on how jet engines operate at temperatures above their components melting point. And how the cold air at altitude is what keeps it from melting. [this video]
Explains engines running above component melting point via cooling air
I want these guys to succeed because they're a mile from my hangar at KAPA, but I guess key questions and points are: Industry is already using single crystal blades and superalloys, so the diagram labeling those is eye candy. No hot-day derate is great, but buyers still care about fuel burn so what does that look like? Power markets care about availability, maintenance cost and TBO in long duration operation. e.g. TBO for a King Air turboprop engine is around 3600 hours. (Sorry I happen to know that space better than others) That's 150 days of continuous operation. Overhaul cost for a P&W engine is around $850K, so a supersonic? I'm thinking a million per engine? And then there's the supply chain manufacturability risk. It's a nice announcement. Here's a video that's been going around the pilot community on how, what Boom is calling "legacy" engines are made. You'll notice they're already using superalloys and single crystal blades and are running at temps that the metal should melt, but are using neat tricks to overcome that. And these engines are flying all around the world today. [this video] You can't build-fast-and-break-stuff with physics at this level. The rules are non-negotiable and you're taking the engineering right to the edge of what is possible and then pushing it a little further to differentiate your product. I think the GE, Rolls and Pratt are watching this and wondering how Boom is going to solve all the problems they've spent decades solving, and then still hav
Shows how existing engines already use superalloys and single-crystal blades
It's exactly what existing manufacturers are doing. What they're calling "legacy". Here, watch this which goes into detail on existing superalloy tech used in todays engines: [this video] and And here's how single crystal blades are already being used in today's engines: [this video]
Details superalloy and single crystal blade tech in today's engines
Just yesterday, someone posted a link to a Veritasium video[0] explaining how a jet engine internal temps of 1500°C work when the components have a melting point of 1250°C. I couldn't imagine doing that at a small scale by hobbyists. [0] [this video]
Explains jet engine temps exceeding component melting points
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