Spark

After hanging up the phone, Chen Nian looked at the preliminarily formed engine data sheet in front of him, secretly feeling a little proud.

The so-called data problem mentioned by Lei Gang is actually a problem of matching and connecting the various parts of the engine. In the final analysis, it is a problem of tolerance.

Why is it so difficult to reverse engineer an aero-engine?

Why do you say that even if you put the aircraft in front of your eyes and let you dismantle it casually, you can't make it?

In fact, to put it bluntly, in addition to the hard index of material, the word tolerance can fully explain it.

A very simple example, assuming that the size of a part is 10 nanometers, but you don't know its tolerance, then when you manufacture it, do you manufacture it according to 10 nanometers or 9 nanometers?

If it is based on 10 nanometers, it is best to be able to recover 100%, but the problem is that there will be tolerances when you manufacture it yourself, which will cause the parts to become 11 nanometers, breaking through the tolerance range, and the parts will be useless.

As for some people saying, then I will directly do it according to 10 nanometers, can't it be strictly reproduced?

nonsense.

If your machine and process can guarantee that you can make 10 nanometers if you say 10 nanometers, then you still have to do reverse engineering.

This technology alone, let alone what you can build, just get some technical patents, and you can get back the design drawings of Aerospace Engineering.

Therefore, standard dimensions and tolerances are indispensable, and what Lei Gang said is exactly this problem.

Standard size and tolerance, this is a golden finger, which can make both data within a relatively reasonable range at one time, which can save the project team a lot of trial and error costs.

Perhaps the steps that required hundreds or thousands of experiments in the past will only need dozens or even less than ten times.

In this way, the rate of efficiency improvement is self-evident.

And now, Chen Nian has mastered such a golden finger.

He pondered for a moment, added a few more data on the paper, and then put down the pen.

At this time, on this piece of paper, the data of the core components of the engine are all complete, including the key parts such as the combustion chamber, the flame cylinder, and the press, and even the process required for processing is marked.

Of course, since there is no specific analysis, these crafts are just names and do not have guiding significance.

But even if it's just that, this blueprint can be said to be invaluable.

If any country in the world, including the United States, which produced the F119 engine, knows the existence of this blueprint, it will do whatever it takes to snatch it.

Because they will not allow their key technology to be lost, let alone allow people who have mastered this technology to live in this world.

After thinking for a while, Chen Nian burned the drawings, then disassembled each component into parts, and began to copy the data one by one.

He planned to hand over the data to Lei Gang in batches after the transcription was completed.

In this way, even if a leak occurs during the process, the data of a single part is not enough to attract the attention of the opponent.

Although the workload inevitably becomes larger, it is absolutely necessary.

After a whole night, Chen Nian finally finished transcribing all the key data. He put the thick notebook in his bag and carried it with him. Then he went to the classroom next to his residence according to the course arrangement, and was ready to start today's class. class.

The teacher who attended the class was Hu Xu, an expert in the field of aerospace materials in a research institute, and what he taught Chen Nianjiang was mainly about materials science.

Since Chen Nian had a certain foundation before, he did not start from the most basic content, but tried his best to ensure that the course fit with the general direction of Chen Nian's aircraft design, and most of the time was spent on titanium alloy casting. The core of the content is the internal crystal defect processing.

There are a lot of pores between the loose powder particles. At the same time, due to the irregular shape of the powder particles and the uneven surface, they are mostly in point contact, so the number of other particles in direct contact with one particle is very small.

When an external force is applied to the powder, under the action of compressive stress, the following situations may occur in the powder body: random stacked powders will move or rotate and approach each other; some powders will be squeezed into adjacent gaps.”

This stage is called example close-up and rearrangement, and after that, it will enter the stage of plastic deformation and diffusion creep.

Of course, these three stages are not completely separate, but work simultaneously to promote the densification of the powder body.

So Xiao Nian, now can you understand why the hot isostatic pressing method can solve the casting problems of most titanium alloy materials?

Speaking of this, Hu Xu paused for a while, looking at Chen Nian who was sitting across from him, waiting for Chen Nian's answer.

In fact, he was extremely reluctant to ask him to teach a freshman class at the beginning.

After all, given my academic status, those who usually listen to me in class must be at least at the level of doctoral students or above.

Such students, no matter what they are talking about, can understand a little bit, and they will learn it as soon as they learn it. All they have to do is to constantly propose new directions for them and give them some inspiration at critical moments.

And what about Chen Nian?

An amateur player with a weak foundation, it took him two full days to understand just the simplest crystal growth model in his opinion.

What's the point of teaching such a student?

He really wanted to give up, but he couldn't refuse due to the orders of his superiors.

So his first two classes were actually very perfunctory.

——

Until one day, the superior suddenly found him and informed him that he had entered the confidential sequence of the No. 22 project, and revealed to him Chen Nian's identity and his contributions during this period.

Complete the key design of an important aircraft, propose two industrial manufacturing processes for new materials, and point out the major technical defects of a key project through verification, save a huge amount of national property, promote the establishment of a project, and take the initiative to undertake key tasks .

Is this something a student can do?

I have been doing research for decades, but what I pursue is just one of them!

And it only took him a few months to complete the Grand Slam

Then, everything changed.

In his eyes, Chen Nian is no longer Chen Nian, but Xiao Nian.

A freshman is no longer a freshman, but a rising star

Because of simultaneous and uniform heating, the movement of the internal molecular structure is affected by the static pressure and can be transmitted uniformly in all directions, which makes the compressive stress on the contact surface of the particles and reduces the shear stress. Even brittle materials can be stably processed plastic .”

That's right! You're a quick learner!

Hu Xu nodded happily, affirmed Chen Nian's answer, and then continued:

Not only that, the hot isostatic pressing method can well eliminate the participating voids in the product and reduce the void volume, which greatly improves the performance and life of the product.

The two asked and answered, Chen Nian asked a targeted question from time to time, and Hu Xu answered patiently.

It wasn't until more than three hours later that all the scheduled course content had been completed, and both of them still had something to say.

Looking at Chen Nian who was taking notes seriously, Hu Xu said sincerely:

Xiao Nian, your talent in material science is not the highest I have ever seen, but your xinxing is definitely the best.

Not only the mind, but also the overall vision is also very good.

You are not like most beginners, you are what you learn. When you learn a subject, you will naturally connect to other subjects.

This kind of vision is rare. If you can persevere, your achievements will definitely not stop there.

Chen Nian chuckled and replied:

I just want to learn more things, which will definitely be useful in the future.

By the way, Professor Hu, I still have your class the day after tomorrow. According to the schedule, I will continue to talk about titanium alloys, but I have a new idea recently. I want to learn about ceramics first. Can you arrange it?

Yes, why not! If I come to adjust the schedule, it will definitely not affect our overall thinking.

Hu Xu readily agreed, and Chen Nian nodded gratefully.

After another class of study, the number of source points he accumulated successfully reached 0.26 points.

So, he plans to start spending money.

The object is the key ceramic-based TBC material in engine technology