Taking the heat-resistant coating on the gas turbine of an aero-engine as an example, the heat-resistant coating used in the returnable spacecraft can be a volatile material when exposed to heat, which can only be effective in a short time, as long as the performance is reliable and the life life meets a certain number of minutes.

However, it is impossible for aviation aircraft to do this, and the life of the product between the two is calculated in minutes, and the other is measured in years, which are two different technology lines.

In particular, the heat-resistant coating used on the blades of aero engines is basically used for the thermal insulation protection of power turbines that withstand high-temperature gas shocks in the combustion chamber, and the toughness of the coating material is an indispensable part of the physical tension caused by the huge centrifugal force generated by the power turbine at extremely high revolutions.

In the early nineties, the operating temperature of the combustion chamber of the international next-generation aero engine was more than 1,200 degrees, and the heat-resistant temperature of the most advanced single crystal alloy in the same period would not exceed 1,000 degrees.

Since the monocrystalline turbine blades of the aero engine and the heat-resistant coating on the attached blades cannot be the same material, then in the face of temperature differences of more than 1,000 degrees Celsius, the different expansion and contraction of different materials will become a very headache engineering problem.

In practical application, once the surface of the blade heat-resistant coating falls off or cracks, the mechanical properties of the single crystal alloy blade will inevitably drop greatly after being subjected to a temperature beyond the limit of the bearing capacity, and the extremely fatal accident of blade fracture compared to the aero engine will occur as scheduled.

"The Americans don't have any good intentions, because of the existence of thermal expansion and contraction, the corresponding single crystal alloy must be matched with the corresponding heat protection coating. Li Yuanling's expression was full of mockery.

"In the research and development of monocrystalline turbine blades, it is necessary to start to consider the expansion and contraction between the heat-resistant coating and the blade substrate, and try to make the thermal expansion coefficient of the two consistent and ...... by fine-tuning the participation ratio of a certain material in the monocrystalline alloy or heat-resistant coating. ”

"The precision involved in this kind of fine-tuning of the elements is basically about 10 parts per million, in other words, the control accuracy of each element in the single crystal alloy must reach six decimal places, if it is not possible in the industry, it means that even if you take the single crystal alloy formula, it is useless. ”

An hour later. Liang Yuan, who was stuffed with a brain full of information about single crystal alloys and heat-resistant coatings, was stupid, wouldn't 10 parts per million be six decimal places?

Liang Yuan suddenly remembered the gold jewelry that the Chinese people loved, and Liang Yuan vaguely remembered that the merchants who first sold gold jewelry first boasted that the purity of their products was four nines after the decimal point, and only began to boast about six nines after the decimal point after entering the new century.

The problem lies in the difficulty of purifying a single metal and controlling the specific proportions of the elements that make up complex alloys, which is equivalent to the difference between a kite and a space shuttle.

What's even worse is whether the single metal purification of the republic in the eighties can get to six nines after the decimal point.

It's no wonder that the general formula of the single crystal alloy in later generations is all over the Internet, and a random search will bring out a lot of information, even if the formula is clearly told to you. Not telling you the specific process and not providing the relevant equipment is doomed to be useless.

"It's just too complicated, Mom, can I think so, as long as GM separates the heat protection coating technology from the first generation of monocrystalline technology that it has mastered, then we can only use one of the technologies to basically get a near-obsolete technology. Liang Yuan asked with a big head.

Li Yuanling nodded and said: "The three types of single crystal alloy heat protection coatings produced and developed by the three major international engine factories are all specially made, except for the heat protection coating initially equipped during the development of single crystal alloys, even if GE's latest single crystal alloy is equipped with Rolls-Royce's best heat protection coating, it is absolutely impossible to develop first-class turbine blades." ”

"Even to be mean. Even if GM provided us with the formulation of the single crystal alloy and the ratio of the heat protection coating, and only embargoed it in terms of equipment, the problem we faced was still very huge. Li Yuanling's expression was a little helpless.

The so-called backwardness of basic industry is by no means something that can be expressed in six simple words, and this backwardness means that every step of the way means that we will face countless problems.

If you count the cost of the introduction of Spey aero engines in the Republic of China, as of now, Yuanjia has smashed at least more than 3 billion yuan in the extremely related fields of aero engines, what do you see?

There is no international top-level blade air film cooling technology, and there is no blade heat-resistant coating technology. There is no single crystal alloy technology, and neither is the integral turbine disk technology. Even without Rolls-Royce's support in terms of equipment and technology, whether the Group's product line of Jewel and Tyin gas turbines can continue to operate smoothly is a matter of choice.

At this time, Brilliance Power is just a large-scale aviation engine assembly and maintenance plant with a little modification ability, even if this kind of assembly plant has to rely on a talented chief engineer like Li Yuanling to successfully complete and put into production.

This pit is really big, but it is much more exciting than the richest man in the world, Liang Yuan thought bitterly.

Of course. Liang Yuan is by no means the only one who chooses to jump into the big pit in this era, such as some behind-the-scenes shareholders who are currently trying to enter the CM100 passenger aircraft aviation development catalog and V2500 aero engine.

Before Liang Yuan, at this time, the Japanese coaxed Rolls-Royce, Pratt & Whitney, MTU, and Fiat to jointly establish the first product of the International Aero Engine Company - the V2500 wide-chord turbofan engine has been rolled off the assembly line.

But Liang Yuan knew how hilarious it was about the seemingly ambitious international joint project, and the cunning Italian had chosen to run away shortly after the company was founded. Only the deep-pocketed West German MTU and the Japanese consortium continue to be in a pit and mud with Rolls-Royce and Pratt & Whitney.

The V2500 project is a multinational consortium of Japan and West Germany, Rolls-Royce and Pratt & Whitney, and then four equally shared, which looks fair and beautiful, and both West Germany and Japan hope to gain the manufacturing experience to build first-class aero engines through this international cooperation.

Of course, if the three major international aviation powers can become the four major ones, it will be more in line with the aesthetics of the Japanese and West Germans.

It's a pity that a wish is a wish after all, and the two guys, Rolls-Royce and Pratt & Whitney, took the R&D funds of the Japanese and Germans, one verified their own new fan concept, and the other verified their own new combustion chamber, and then the two changed hands to put the new technology on the Ruida series and PW4000 series.

Twenty years later, Japan's Ishikawashima Harima Heavy Industries, which has rich experience in international cooperation, can produce world-class power turbines, and Germany's MTU power turbine production capacity is also at the world's top level, but neither of these two can design even a small thrust aero engine.

As for the fate of the V2500 engine, it can be said that from the moment of birth, it began to be beaten by GM's CFM series, in fact, if Pratt & Whitney and Rolls-Royce really join forces, even if they don't crush GE, there is no problem, and the embarrassing performance of V2500 can only prove that these two giants are simply malicious paddling.

Finding that Liang Yuan's mood was not high, Li Yuanling comforted and said: "Actually, things are not bad, Xiaoyuan should know that it is much easier to introduce equipment than to introduce technology." ”

Liang Yuan nodded and asked, "I still don't understand my mother and Wu Lao's intention of choosing heat-resistant coating technology and afterburner metal heat treatment technology. ”

"As far as the field of aero engines is concerned, the difference between choosing a single crystal alloy or a heat-resistant coating is not big, and the reason why the teacher chose the heat-resistant coating actually has a lot to do with the Su Gong side of Gangji Power Collector. Li Yuanling said with a smile.

"What does it have to do with Lao Su?" Liang Yuan looked stunned.

One is an aero engine under the category of engineering thermophysics, and the other is a large-scale integrated circuit under microelectronics technology.

Seven or eight high-end sounding techniques were rejected by Li Yuanling with a smile, and finally Liang Yuan finally gave up his guess, and watched Li Yuanling wait for his mother to uncover the mystery. (To be continued......)