Ultimate Scholar

"For aero-engine fan blade materials, there are currently three main materials used."

"One is nickel-based materials like FGH4098-15, and then there are single crystal high-temperature alloys. FGH4098 is also a member of this type of material, followed by composite high-temperature materials."

“The most important point among single crystal superalloys is to use a single crystal as a unit, so that the final material is alloyed to a higher degree, thereby improving the various properties of the material, especially when working in high temperature environments, and even It can ensure strong performance even when working in an environment that can dissolve. ”

"That's the most important thing."

For most materials, when the temperature is high, their properties such as strength may have become weaker, their tensile strength has become lower, etc.

Such materials certainly cannot be used in aircraft engines.

For single-crystal superalloys, they are materials that can maintain strength at high temperatures and will not suddenly break when the turbine rotates at high speed.

"As for composite high-temperature materials, there are many main types of materials, including resin-based, ceramic-based, carbon/carbon-based, and metal-based. However, in terms of performance in practical applications, ceramic-based is still the best. "

"So which one to choose...? That's the question."

In the materials laboratory of Sheshan Research Institute, Li Mu sat in front of the computer, searching for various information and thinking slightly in his heart.

Regarding this issue, it can be regarded as a problem that makes every researcher’s head hurt when it comes to the selection of aero-engine materials.

After all, no one knows what kind of performance these different materials can have after different combinations.

Just being able to withstand high temperatures is not enough. Otherwise, tungsten, a material with a melting point of more than 3,400 degrees, would have been used in aircraft engines long ago.

It also has low density and low thermal brittleness. Like tungsten, even if it can withstand high temperatures of more than 3,000 degrees, it will become very brittle at 400 degrees. In addition, its density is extremely high, so it will basically not be considered. Used on aircraft engines.

However, after several days of thinking, Li Mu already had his own preliminary thoughts.

"Nickel-based single crystal superalloy is relatively trustworthy."

At least there is a mature example in front of him now. For Li Mu, all he can do now is to use past successful cases to assist.

Just like single crystal superalloys, they were originally derived from a material strengthening method called dispersion strengthening.

Without much hesitation, Li Mu made a decision - to carefully analyze the existing materials first.

"Then, let's first analyze the different internal properties of single crystal superalloys with different properties."

As for where these materials come from, Li Mu doesn't need to worry. Cheng Guodong provided him with a variety of information, including a variety of single crystal high-temperature alloy materials currently used by the military.

The information is very detailed, including a variety of metallographic diagrams, spectral diagrams, etc. It basically has everything you can find, even the relatively useless ones.

And this also provided Li Mu with considerable convenience.

Because, if you want to use the theory of electronic behavior of materials to analyze materials, the more detailed the information in this area, the better.

Therefore, Li Mu made considerable progress as soon as he got started.

A pile of draft paper was filled with various calculations. Li Mu looked at these calculations and nodded with satisfaction.

"Yes, now we have basically fully analyzed the principle of electronic behavior and how powdered superalloys can still maintain high strength at high temperatures."

"Under this special casting method, the harmful phase precipitation of this type of alloy at high temperatures has been greatly alleviated, overcoming the segregation of conventional alloys."

"So... uniformity is the most important thing."

Li Mu started thinking in his mind.

In ordinary alloys, due to casting methods, different components may be unevenly distributed within them. Therefore, under high temperatures, these unevenly distributed components may break away from alloying and precipitate directly. In this way, This also destroys the internal integrity of the alloy.

Just like that sentence, fortresses are breached from the inside, and the same is true for hard alloys. Independent particles appear inside, which naturally makes the high-temperature strength of the alloy worse and becomes easier to break.

Li Mu took out one of the documents nearby. This document was a metallographic diagram of the fracture surface of a blade on WS-22 that suddenly broke after a long period of high-speed operation in a high-temperature environment.

It is easy to analyze that the harmful phases in it are the culprits that caused its breakage.

"This shows that the powder metallurgy process they used is still weak in uniformity."

"So the goal is very clear. How to make the metal components in the alloy more uniform is a very important direction."

Li Mu casually wrote two words on the scratch paper: craftsmanship.

The quality of the process will become an important factor in the uniformity of the alloy, which will have a huge impact on engine performance and determine the life of the engine.

For example, the life span of the WS-15 engine is rumored to be about 2,000 hours or 4,000 hours, but Li Mu has more detailed data, which is about 3,600 hours.

The key to determining this life is the blade material.

"And the second goal is to continue to improve the formula."

"Well……"

Well, this is actually relatively simple for Li Mu. Using the computer in his mind, he can simulate it day after day, and based on the calculation of the electronic behavior principle of the material, he can easily improve the current alloy formula.

But if the process does not change, there will definitely still be problems.

"However, the process needs to be studied slowly. As for the formula, one can be made first, so that the subsequent new process can be designed based on the new formula."

Thinking of this, Li Mu took action and started designing a new formula.

With the help of the computer in his mind and the new theory, Li Mu came up with a new formula in half a month.

…

"This recipe...are you sure it works?"

In the base, with the new formula brought by Li Mu, the researchers from the four research institutes were all confused.

It's only been three weeks since they invited Li Mu, and now he's come over with a new recipe?

It is true?

Li Mu spread his hands and said, "You will know after you run it with the supercomputing model."

Hearing what Li Mu said, several people looked at each other and then made a decision.

"Okay, let's try running for a while first."

…