China rapidly narrows technology gap with S. Korea

[XiaoYaoZi]

Most Chinese members are now considered Japan as a "科技伪强国".

Most Chinese netizens aren't buying the crap that "Japan is technologically superior", only the US is a real challenge.

日本人的太空项目根本没多少料，还拼命吹牛掩饰。

 

[ChineseTiger1986]

日本人的太空项目根本没多少料，还拼命吹牛掩饰。

When Japan was trying to initiate an arm race with China, she immediately got exposed that her military technology is much inferior to China's.

Shinshin was just the beginning of the jaw dropper for those people who initially believed that Japan could build the superior military hardwares if without any restriction.

Japan's N-1/H-1 rocket is a derivative of America's Delta rocket (see GlobalSecurity citation below).

Delta III and Delta IV | GlobalSecurity
"The H-1 was a Delta derivative, arising from the licensed production of the Delta 1 as the N-1."
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The Japanese N-2 rocket is also a derivative of America's Delta rocket, but I can't find a citation for it. It's not easy to prove that Japan is merely using licensed American technology. The mass media tries to hide the fact.

I recall this fact, because I watched a documentary about it a long time ago.

Right now, we only have Wikipedia's chronological narrative.

"The N-II or N-2 was a derivative of the AmericanDelta rocket, produced under licence in Japan. It used a Thor-ELT first stage, a Delta-F second stage, nine Castor SRMs, and on most flights either a Star-37E or Burner-2 upper stage, identical to the US Delta 0100 series configurations. Eight were launched between 1981 and 1987, before it was replaced by the H-I, which featured Japanese-produced upper stages. All eight launches were successful."

Can you dig out the origin of the H-IIA/B rocket?

 

[Martian2]

When Japan is trying to start an arm race with China, she immediately got exposed that her military technology is much inferior to China's.

Shinshin was just the beginning of the jaw dropper for those people who initially believed that Japan could build the superior military hardwares if without any restriction.



Can you dig out the origin of the H-IIA rocket?

I found a citation to prove that the Japnese H-IIA rocket is a licensed derivative of the American Delta rocket.

N-II (rocket) | Project Gutenberg Self-Publishing - eBooks | Read eBooks online

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It is common knowledge that Japanese rockets are based on American Delta rocket technology. It is only on PDF that people do not know this fact.

"Buran:

The H-2A rocket is based on earlier Japanese rockets, which were in turn based on a licensed derivative of the US Delta II rocket, which has been incredibly successful but has now been withdrawn from service in favor of the Delta IV (I don't know why III was skipped.)"

 

[XiaoYaoZi]

Japan's N-1/H-1 rocket is a derivative of America's Delta rocket (see GlobalSecurity citation below).

Delta III and Delta IV
"The H-1 was a Delta derivative, arising from the licensed production of the Delta 1 as the N-1."
----------

The Japanese N-2 rocket is also a derivative of America's Delta rocket, but I can't find a citation for it. It's not easy to prove that Japan is merely using licensed American technology. The mass media tries to hide the fact.

Most Japanese so-called space technologies can be found the direct technology sources from Europe or America. Their most space current technologies has lagged behind us because of the lack of R&D investment in these fields such as anti radiation chips, satellite borne system .etc long time (European included) though they can get the support from the west.

 

[ChineseTiger1986]

Most Japanese so-called space technologies can be found the direct technology sources from Europe or America. Their most space current technologies has lagged behind us because of the lack of R&D investment in these fields such as anti radiation chips, satellite borne system .etc long time (European included) though they can get the support from the west.

I truly think that South Korea and Japan are more appropriate for the comparison.

Just look at their military hardwares are also similar to each other; basically a hub of the American products.

 

[XiaoYaoZi]

I truly think that South Korea and Japan are more appropriate for the comparison.

Just look at their military hardwares are also similar to each other; basically a hub of the American products.

In 2006, Japanese and Koreans has been bragging their Fourth-generation fighter programs, when we just exposed our J10 fighter. In 2016, our J20 start into service and the four-generation fighters of Japanese and Korean still are in the paper.

 

[gambit]

Most Japanese so-called space technologies can be found the direct technology sources from Europe or America.

And you think China's space technology is not acquired from others, such as the Soviets/Russians and even US ?

 

[Martian2]

Japan and South Korea are both technology beggars.

Japan and South Korea have to beg the United States for a transfer of technology through licensing.

China spent 30 years developing its own DD3 and DD6 nickel-superalloy single-crystal engine blades (see citations below). Through sustained heavy investment, China develops its own technology.

China has two stealth fighters in the prototype or production stage: the J-20 and the J-31.

In contrast, the Korea Times reports that the United States rejected South Korea's request to transfer four key F-35 technologies for the KF-X.

KF-X project dealt further blow

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DD6 is China's second-generation nickel-based single-crystal superalloy
1. First generation nickel-based single-crystal superalloy was called DD3. This technology was probably used in the WS-10A and WS-13 turbofan engines.
2. Newer second-generation nickel-based single-crystal superalloy is named DD6. This latest technology will probably be incorporated into the WS-15 turbofan engine.





Figure 1. (a) HAADF image of alloy DD6 before the creep test. (b) Element mapping images of major constituents corresponding to the area denoted by a white rectangle in (a). (c) Distribution of elements Re and W along the direction perpendicular to the interfaces. The dashed vertical lines show schematically the γ/γ′ interface.

Source: ScienceDirect.com - Scripta Materialia - Distribution of rhenium in a single crystal nickel-based superalloy

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DD6 single crystal alloy TLP diffusion bonding process

"DD6 single crystal alloy TLP diffusion bonding process
发表于 2012/08/17 由 admin

DD6 is China's second-generation nickel-based single crystal superalloy with high temperature strength, good overall performance, and organizational stability. With the first generation of nickel-based single crystal superalloy DD3, Cheng Wen capacity increase of about 40 ° C; compared with foreign widely used second-generation single crystal alloys, tensile properties, long-lasting performance, oxidation resistance and heat corrosion all reached and even some more than its level, and containing rhenium low low-cost advantage. Of the alloy is suitable for the production of work below 1100 ℃, gas turbine blade and other high temperature parts with complex cavity [1-3]. Apparently alone casting technology to manufacture the hollow blades with complex cavity is very difficult, even impossible, only the casting and welding the two processes combining to make it a reality. The single crystal alloy as a single crystal highly efficient gas-cooled modular blade manufacturing process, the most important one of the key technologies, foreign countries have to conduct more studies, transient liquid phase diffusion bonding (TLP diffusion bonding) on ??the single crystal turbine blades connection shows a clear advantage and feasibility [4,5]. P & W Company has adopted the TLP diffusion bonding technology to produce outside the compound single crystal blades, and is used on the F100 engine [4]. Developed in our second-generation nickel-base single crystal superalloy DD6 for the study, TLP diffusion welding head the organization and performance analysis.

A test of materials, methods and equipment
Test the parent material for the DD6 single crystal alloy, its composition and typical rupture properties shown in Table 1, the standard heat treatment specifications for the 1290 ° C, 1h from +1300 ° C, 2h +1315 ° C, 4h, air-cooled +1120 ° C, 4h, air-cooled +870 ° C , 32h, air-cooled. TLP diffusion bonding intermediate layer alloy is prepared for DD6 are basically the same, the main component DD6 base metal, adding a certain amount of B as the melting point depressant elements, use the form -150 purpose powder.

Surface preparation before welding in order to prevent the machining stress lead to recrystallization in the base metal in the welding thermal cycle, using the + wire cutting + sanding base metal heat treatment processing. Before welding, all samples with acetone ultrasonic cleaning to oil.

Diffusion welding temperature used to match the temperature of solution treatment with the base metal, ie, 1290 ° C, holding time requirements through tests to determine in accordance with the joints lasting performance.

Docking sample connector metallographic sample and performance samples are first 0.1mm thick stainless steel gasket sandwiched between both ends of the specimen connected surface, and TIG welding positioning, then as usual brazing fill plus brazing powdery intermediate layer alloy is placed in the sample above the binder positioning. Connection, the intermediate layer alloy melt into the cracks in the formation of joints. In order to ensure that the two matching samples of crystal orientation consistent to avoid or reduce the formation of the joint to reduce the mechanical properties of grain boundaries in the test specimen strict matching processing and precise positioning of assembly and welding to ensure that two specimens relative position.

Figure 1 shows the form of the specimen measured the lasting high temperature mechanical properties, optical microscopy, scanning electron microscopy, energy dispersive analysis by means of diffusion welding the head of the organization of different holding time were observed and analyzed."


China built indigenous DD3 nickel-based single-crystal superalloys prior to 1995



Fig. 1. Microstructure of the DD3 single-crystal superalloy, respectively, solidified at undercooling of (a) 130 K; (b) 155 K; (c) 170 K; (d) 180 K; and (e) 210 K. (Source: Recrystallization mechanism for the grain refinement in undercooled DD3 single-crystal superalloy)

Most people seem to be unaware that China has been building DD3 nickel-based single-crystal superalloys for about twenty years.

The indigenous WS-10 turbofan engine project started in 1986. By 1992, the "first test engine [was] completed and bench testing began." Therefore, we can deduce China was probably building DD3 single-crystal superalloys a few years prior to 1992.

The earliest English citation (see article below) that I found for China's DD3 single-crystal superalloy was in 1995. Also, the earliest English citation that I found for China's DD6 second-generation single-crystal superalloy was in 2003.

The point of these citations is to match the known dates for China's DD3 and DD6 single-crystal superalloys with the known dates for China's first tests of the WS-10 and WS-15 turbofan engines. They match almost perfectly.

China was building DD3 nickel-based single-crystal superalloys by the late 1980s or early 1990s and the indigenous WS-10 engine was tested in 1992.

Also, GlobalSecurity reported that China successfully tested its WS-15 engine prototype in 2005. Based on the citation, we can place the approximate date of China's manufacture of DD6 nickel-based single-crystal superalloys around the early to mid-2000s.

The timeline for the DD3 and DD6 superalloys fits the dates for testing the WS-10 and WS-15 turbofan engine prototypes.

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Advanced Performance Materials, Volume 2, Number 3 - SpringerLink

"Advanced Performance Materials
Volume 2, Number 3 (1995), 217-229, DOI: 10.1007/BF00705445
Some recent developments of advanced titanium alloy and nickel base superalloys in BIAM

M. G. Yan, Y. F. Han, C. X. Cao and Z. T. Wu

Abstract

A brief review of recent research and development works of some advanced Ti alloys and Ni base superalloys in the Institute of Aeronautical Materials, Beijing (BIAM) is reported. In which, the tensile deformation and fracture characteristics in an agr-beta Ti alloy, the creep behavior of Ti3Al intermetallic alloy and effect of heat treatment and crystal orientation on the creep properties of a single crystal Ni base alloys DD3, are presented. The applications of the above mentioned alloys in aeronautic industry are described.

Mechanisms of Low Cyclic Fatigue of DD6 Alloy at Elevated Temperature--

"《Journal of Aerospace Power》 2003-06
Mechanisms of Low Cyclic Fatigue of DD6 Alloy at Elevated Temperature
LI Ying, SU Bin (Beijing Institute of Aeronautical Materials, Beijing 100095, China)

Low cycle fatigue mechanism of a single crystal nickel-base superalloy,DD6,has been investigated at 760℃ and 980℃. It was found that there were two kinds of sites where crack initiates, one being the surface of the specimens and the other being the sub-surface. Microcracks and oxide layer on the specimen surface are potential crack initiation sites in this superalloy. Secondary crack,reared ridge, and microcrack in the front of the main crack tip can all hinder crack propagation during low cycle fatigue.

 

[XiaoYaoZi]

And you think China's space technology is not acquired from others, such as the Soviets/Russians and even US ?

The technology exchanges among countries are very normal, but because of the embargo of the western to us the technologies we got from the west are very limited and insignificant. For the stingy Russians, we have been ahead of them in many many fields of space technology except some limited fields such as some rocket engines, nuclear battery .etc.

 

[gambit]

Japan and South Korea are both technology beggars.

Japan and South Korea have to beg the United States for a transfer of technology through licensing.

China spent 30 years developing its own DD3 and DD6 nickel-superalloy single-crystal engine blades. Through sustained heavy investment, China develops its own technology.

China has two stealth fighters in the prototype or production stage: the J-20 and the J-31.

In contrast, the Korea Times reports that the United States rejected South Korea's request to transfer four key F-35

This simply means Japan and South Korea wanted their 'stealth' fighters programs to be expedited with US assist, not that they cannot design and build their own. If they want to buy the whole product, we may and would sell, but not the programs that built the jet. If you have any experience in R/D and manufacturing, you would understand that.

The technology exchanges among countries are very normal, but because of the embargo of the western to us the technologies we got are very limited and insignificant.

The technological embargo is not the point.

The point is that China's current technological standing cannot exist without external assist, and by the word 'assist', I do not mean cooperation but that the knowledge came to China one way or another.

 

[Martian2]

This simply means Japan and South Korea wanted their 'stealth' fighters programs to be expedited with US assist, not that they cannot design and build their own. If they want to buy the whole product, we may and would sell, but not the programs that built the jet. If you have any experience in R/D and manufacturing, you would understand that.


The technological embargo is not the point.

The point is that China's current technological standing cannot exist without external assist, and by the word 'assist', I do not mean cooperation but that the knowledge came to China one way or another.

No. China built its own technology.

No one helped China's atomic bomb project. China detonated an atomic bomb in 1964.
No one helped China's hydrogen bomb project. China detonated a hydrogen bomb in 1967.
No one helped China's ICBM project. China launched the DF-5 ICBM in 1971.

China has a history of proving it can indigenously build hi-tech weapons.

China's WS-10 turbofan engine can be traced to the DD3 nickel-superalloy single-crystal blade research and development. China had been building turbojet engines for decades. China only needed the DD3 nickel-superalloy single-crystal turbofan engine blade.

China's WS-15 turbofan engine can be traced to the DD6 next-generation nickel-superalloy single-crystal blade.

China's AESA radars are numerous for ground-based, ship-based, and aircraft-based versions. China has a long history of developing its own AESA radars.

The list goes on. You can trace Chinese technology to very early primitive versions.

China's CCRSS hyperspectral 328 electromagnetic band satellite is another case in point. You can trace it back to an aircraft-based low-resolution predecessor and an improved model on Shenzhou 3.

 

[XiaoYaoZi]

This simply means Japan and South Korea wanted their 'stealth' fighters programs to be expedited with US assist, not that they cannot design and build their own. If they want to buy the whole product, we may and would sell, but not the programs that built the jet. If you have any experience in R/D and manufacturing, you would understand that.


The technological embargo is not the point.

The point is that China's current technological standing cannot exist without external assist, and by the word 'assist', I do not mean cooperation but that the knowledge came to China one way or another.

The fact is that you are more willing to accept relatively the realties. For the sophisticated programs like the forth-generation fighter, the countries, Korea and Japan you bragged has forever inevitably lost the capacity to contain all the technology chains, they must import technologies from other countries.

 

[jhungary]

The Airbus A380 was joint effort between many countries, and it also uses the US/UK turbofan jet engines.

You cannot give the entire credit to one country.

Except the US, no western country can build the Airbus A380 or even A320 alone.

Actually, you are wrong.

A380 can be build by all EU parts and avionic (R&R Trent Engine, Thale's Fly by wire system, and BAe Power by wire system) Or total US system (Engine Alliance GP-7000 engine, Lockheed Fly-by-Wire system and US patent FADEC system) or mix. The system EU/US interoperability is due to different country have a different service origin and for country like Singapore, the service origin would be EU/UK and for country like Canada and US, they won't service RR engine and they will only service US parts.

EU (precisely speaking UK + France + Germany) can build a A380 from scratch

 

[Monkey King]

Korea is still more advanced in the area of integrated semiconductor circuits. However, the gap is quickly narrowed in recent years. China is ahead of S. Korea in heavy-industries such as machinery, military, space technology and high-speed trains. As to the relatively "new" industries including new energy, robots and drones, China is way ahead of S. Korea. Just a personal view.

 

[kuge]

any south korean pdf member over here to comment?