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by dmitrygr·1mo ago·view on hn ↗
Material sciences needed for modern jet engine blades are a closely guarded secret, and thanks to not manufacturing them in china, those secrets have managed to remain not stolen.

Fun story: it is not just jet engines - it is only recently that china was able to actually make indigenous ballpoint pens https://www.bbc.com/news/business-38566114

7 comments
It is not the pen, it is the pen tip. Ballpoint pen tips are microscopic tungsten carbide ball held inside ultra-thin steel sockets. So you need cutting tolerances precise to 0.001 millimeters. If the socket is a fraction of a micron too loose, the ink leaks. Too tight, and the pen won't write.

Source from al-Arabiya: https://english.alarabiya.net/variety/2017/01/14/At-last-Chi...

The point (no pun intended) is that China was beginning to crack the processes for making the precision machine tools that make machine tools.

The ballpoint pen was invented in 1938. It doesn't rely on any arcane manufacturing technology.
I am 47 and ballpoint pens have visibly improved since the 1990s, at least the cheap ones (never had an expensive one). The risk of accidental staining is by now basically zero, it used to be high enough that you avoided putting a pen into your shirt pocket even for an hour.
Hence the fading away of the "nerd with pocket protector" stereotype...
They do. The micro-precision subculture required to (in order):

1. Powder prep your tungsten carbide

2. Form said powder

3. Thermally prepare the resulting slurry using a vacuum forming furnace

4. Finish it with diamond lap grinders, lapping machines and polishing machines

5. Clean it ultrasonically, with solvent, rinse, then dry them.

6. Have the metrology required to test thousands of micron-scale balls a day (a world-beating skill in itself)

7. Build a QA lab that can assure the quality of said balls statistically (you can test them all).

8. And then integrate them via socket assembly

are not just hereditary, but proprietary. And assuming a competitor does manage to achieve the basic ISO 3290 and ASTM F2094 standards, you still need tacit knowledge. Stuff like sintering temperature curves, proper powder grain distribution, polishing chemistry, proper statistical rejection thresholds and a whole lot more.

And that is just the ball. Not the socket, or the ink channels. Making a perfectly spherical 0.5 mm ± 0.0001 mm tungsten carbide ball requires the same techniques used in building micromotors, medical devices, and semiconductor subcomponent manufacturing. Techniques such as high-volume sorting, advanced powder metallurgy, controlled sintering, and precision machines that operate 24-hour shifts without drifting. All operated by modern process engineers who are the spiritual (or actual?) descendants of Swiss watchmakers or the glassmakers of Murano.

They are not microscopic! I can easily see the balls in the tips of ballpoint pens.
The ball is not microscopic, but the tolerances required to make the ball spherical and fit into the socket are.
Exactly, so this sentence is incorrect:

> Ballpoint pen tips are microscopic tungsten carbide ball held inside ultra-thin steel sockets

Yes indeed, you are correct. My mistake.
The BBC article even mentions that they are milliscopic, not microscopic.

> 2.3-millimetre

China's ballpoint pen quality as a reflection of manufacturing quality:

" China's inability to produce a complete, high-quality ballpoint pen came to widespread attention in 2015, when Prime Minister Li Keqiang singled out the products at a seminar in Beijing, noting that his writing was "rough" when he used Chinese-made ballpoint pens. For Li, China's failure to manufacture a complete ballpoint pen was indicative of the Chinese economy's weaknesses. "That's the real situation facing us," Li said at the time. "We cannot make ballpoint pens with a smooth writing function." "

https://www.smh.com.au/world/finally-china-manufactures-a-ba...

You fell for a meme that was tired years ago already (your link is from 2017, after all). The article itself notes, “Relatively low-value items, like ballpoint pens, have not been a priority”, so obviously this says little about higher-priority military and industrial areas to which the CCP devotes greater effort.
Ball point pens are surprisingly high precision items. Making a good ball point pen is not easy.
is it really a tired meme?

its a clear prioritzation choice from the government, and that prioritization is itself a technology

notably this same prioritization mode resulted in the soviet union failing to produce quality of life improvements for its citizens.

the failure is that the CCP is unable to prioritize making simple useful stuff

Have you been to urban China anytime after that 2017 article? The country is now as developed as anywhere else, indeed it feels like it is gradually overtaking other developed countries. The comparison to the Soviet Union feels ridiculous to anyone with a firsthand experience of the country.
The political push in the US to cling to legacy fossil fuel technologies feels to me more Soviet-like if anything.
Not really, the Soviets pushed all sorts of new transportation and energy generation ideas, not to mention nuclear.
What country do you live in, and are they currently capable of making ballpoints?
It's not even that. You can have all the designs you need, but you also need a bunch of downstream tech to get from drawings to production. This is something that centrally planned economies struggle with. You can't 5-year-plan your way to jet-engines if you haven't previously 5-year-planned for all the auxiliary infrastructure needed to support that.

We already know this was an issue with the soviets, back when they had the plans for us jet engines (for fighter planes), but couldn't replicate them. Same for stealth, hell even some of their rocketry. And the soviets had plenty of auxiliary systems already in place, during the cold war. As someone said above, they could do quantity, they could do limited high-quality, but couldn't do both at the same time.

There are things that work with 5-year plans: railroads, road infra, buildings, etc. And there are things that are not that easy, and take multiple decades from when the order comes to having it realised. Something that's not immediately obvious for western folks is that when you mix central planning with authoritarian governments, you will get a huge number of pain points along the way, where orders come downwards towards the ones executing them, and overreporting/missrepresentations/lies go upwards. It's like the longest game of telephone, where you start from the top, demanding x y z, get reports that you're on your way of getting 3x, 3y, 3z and in reality you have some of x, none of y, and z looks like z but it's actually three x's in a trench coat.

This is of course exemplified by the joke - what's the famous Soviet machine that cuts wood into two pieces? One that cuts wood into three pieces.
Isn't China currently among the leaders of material science with lots of top 10 universities located in China? [0] (in rankings that do not incorporate prestige but actual scientific output)

[0] https://scholars-stage.org/china-and-the-future-of-science/

its difficult to see from the lens of software and information technology, and open source academia, but physical science is often discovered via experimentation and cant just be brute forced. usually it disseminates as it is adopted into industrial process and is then copied. a lot of scientific discoveries are made due to impulsive-creative intuition

for example: - until the end of ww1 the haber bosch process was confined to germany

- jet engine turbine blades today

- most historically: https://en.wikipedia.org/wiki/Greek_fire , medieval napalm that nobody has been able to replicate even now

Quantity isn't quality.
Isn't having universities in global top10 actual quality?
Where are the jet engines?
In the making I'm sure. It's really naive to think that jet engine is challenge that won't be overcome.
In the J-20Bs
All I know is that they produce a lot of engineers, while the US produces a lot gender studies majors. I rarely say it, but I do not foresee much that they won't be leaving us sharply behind on soon, other than poverty and homelessness, which we have pretty well covered.
There are about as many gender study majors in the U.S. per year as there are aviation engineering majors. That is one small niche of engineering majors that includes all of gender study.
I guess I can relax and stop worrying that we're falling behind a bit. But I do wonder what the numbers really are, and just how many engineers we produce compared to China, of course, without qualifying everyone that learned Visual Basic as an engineer, unless, of course, that's where they're actually getting their own numbers from.
I see you're getting downvotes, but my intuition strongly aligns with yours. Many of the top minds/academics in (North) America are from overseas, and most of the time that's India and China. And it's been this way for a long time, and it basically makes sense from a numbers perspective. Note that I say this without a particular bias for or against.

So when many of the top minds, publishing most of the top papers in your country got educated in USA but will most likely return to their country of origin - that needs to be factored in to the calculation (especially if tensions increase). At the end of the day I think it's arrogant and wrongheaded to pretend that the USA has dominance in R&D, against China in particular.

That's actually pretty bad. The rest of the world is very willing to spend money on American aerospace products and services.

Is it willing to buy gender theory from you for similar amounts of money? If not, the production of specialized majors should not be 1:1.

Even in our "productivity at any cost" society, sometimes people still study things that they find interesting. That's probably a good thing, in the long run.
Do you think its zero sum? We could just put all the gender studies students into engineering and expect them to thrive there?
I think your understanding of the numbers is multiple orders of magnitude off. Looking at a recent year (2024) in the US, the total number of "Area, Ethnic, Cultural, Gender, and Group Studies" majors graduated 11961, whereas "Engineering" was 193,458 and "Engineering/Engineering-related Technologies/Technicians" was 83,665.

From: https://nces.ed.gov/ipeds/SummaryTables/report/360?templateI...

Seems they have figured out the single crystal blade tech https://interestingengineering.com/innovation/china-crystal-...
From the article:

> DD6 is a second-generation nickel-based single-crystal superalloy developed by the institute with fully independent intellectual property. Its chief engineer, Li Jiarong, said the alloy’s performance matches or exceeds that of comparable second-generation superalloys used in Europe and the United States, at a lower production cost.

US manufacturers have already developed sixth-generation SC superalloys and most Western airlines are on engines with third- and fourth-generation materials.

The technology behind single crystal superalloys is relatively well understood, the problem is getting the process reliable enough to be economical in an industry that requires tens if not hundreds of billions of dollars to develop through trial and error. The TFA's point is that unlike EVs or semiconductors, the turbofan industry is between a rock and a hard place that China's other successful industries weren't.

TFA = The Featured Article/The F**ing Article
The word is "fucking". We’re grown-ups, we can use grown-up words.
Can Chinese companies order just the blades from RR or P&W?

I've watched their manufacturing video recently and shocked how much of it was hand labour - it's not something I'd associate with precision. My partner said they must know better tho lol.

The RR video showing manual assembly of wax molds is a low volume development line. It isn't their main production process.
I've seen that video. Guaranteed they wouldn't have put the slightest bit of information in there if they thought would help the competition.
They can order engines from RR or P&W

But those companies have no commercial interest in supporting a Chinese manufacturer that just wants the blades even without export controls, when they can make much higher margins selling whole engines that must be maintained using their parts (in practice variants of the engines destined for COMAC also omit some of the IP that finds its way onto Airbus and Boeing because you can help a customer too much...)

recently? and you posted an almost 10yo article?
yes, compared to the length of time ballpoint pens have existed (88 years -- since 1938), this is very recent - only 9 years ago