Chapter 1071 Chief Engineer Gao is spying on us? (First chapter, three more to go)

Gao Zhendong had no idea how the final decision on the fighter jets was made. The Defense Work Committee even deliberately kept him in the dark, and the reason was self-evident.

But this has no impact on Gao Zhendong's own work, he just does what he should do.

After much preparation, the comrades from the Northeast Carbon Research Institute finally arrived in Beijing. As they had not been here for some time, they felt something different as soon as they arrived at the Third Factory.

This place seems even more difficult to enter.

Fortunately, they had a legitimate reason and all the necessary registration and application were done. Overall, it was fine and we were able to see them.

"Chief Engineer Gao, it's been a while since we last met. Haha." When Engineer Duan saw Gao Zhendong, he started laughing. This was his personality, a wonderful person who was rough on the outside but meticulous on the inside.

"Yeah, you know what, I miss you guys a lot." Gao Zhendong found it relatively easy to deal with him. They had known each other for a long time, had a lot of exchanges, and dealt with a lot of things. They were old acquaintances.

Old Duan's reaction made Yu Yuncheng, who was standing by, a little envious: "Ah, really? Look, we sensed your longing and came to find you."

It sounded as if Gao Zhendong had taken great advantage. Not to mention others, even Yu Yuncheng, who had spent much more time with Gao Zhendong than Lao Duan, felt that he could not say it because he did not have the nerve to do so.

But not only did Old Duan say it, he was also certain that Gao Zhendong would agree.

As he expected, Gao Zhendong burst into laughter: "Then I must thank you first. Tell me, what is it?"

Gao Zhendong knew that if there was no important work, they would not come to him.

When it comes to business, Lao Duan immediately admitted his mistake: "Hey, our Chief Engineer Gao is really good. He knows that we have encountered a problem again. You don't know, this matter has stumped us for a long time..."

The old guy's expression changes so quickly, and the emotions he contains are so appropriate and genuine, it's really unique. Looking at his face, there is a smile mixed with a bit of sadness, and he is just about to cry.

Yu Yuncheng was stunned watching from the side. He had been working with the Northeast Carbon Research Institute for such a long time, but he had never seen this old guy perform like this.

Old Duan looked at him and squinted his eyes. Hey, this skill is not usually shown.

"What's the matter? Our Duan Gong is so frustrated." Gao Zhendong smiled happily. Old Duan is still fun.

Old Duan's expression straightened up: "Speaking of this, I would like to thank you for finding a topic for us..."

As soon as he mentioned this matter, Gao Zhendong knew what was going on.

——Pyrolytic graphite!
"Haha, I see. Is it a problem with pyrolytic graphite?"

Old Duan nodded vigorously: "Yes, yes, yes! That's it. We have been bothering Comrade Yu Yuncheng about this matter for a long time, but the result is not so satisfactory."

Gao Zhendong probably understood and stretched out his hand: "Let me see the result."

Yu Yuncheng handed the experimental results that he had prepared long ago to Gao Zhendong.

Gao Zhendong took a glance and frowned.

"The sample area cannot be made large, and the thickness is not high... well, this is a problem." If the sample area cannot be made large, it means that this thing cannot be truly used and can only be used for research at most.

The area is small and the thickness cannot be made large, so even if it can be used, the scope of application is extremely narrow.

"The density is a bit low, which means the porosity is a bit large..." Pyrolytic graphite is a kind of polycrystalline carbon, but if it is made well, it can even have properties close to single crystal carbon. With such a small density, it naturally cannot be called qualified polycrystalline carbon.

“This thermal conductivity...hiss..." Gao Zhendong was a little shocked. It was not that the data was too good, but too bad...There is indeed a difference in the two directions, but the difference is completely without the performance of highly oriented pyrolytic graphite. The thermal conductivity of highly oriented pyrolytic graphite in two directions can even reach a difference of more than 100 times.

Theirs is obviously far from that, and even in different batches, there are isotropic situations.

"Mechanical performance... never mind, just make do with it." This was the only thing Gao Zhendong didn't complain about.

Listening to Gao Zhendong's mumbling, both Lao Duan and Yu Yuncheng felt a little embarrassed. This thing was really not presentable enough, and it was no wonder that Chief Engineer Gao was so surprised.

The only consolation for them is that they have achieved relatively obvious anisotropy in thermal conductivity.

This proves that there is no problem with the technical route pointed out by Chief Engineer Gao. If there are any problems, they are all on our side.

"Mr. Gao, this... I'm really sorry. My research on chemical vapor deposition of specific substances is not in-depth enough, and I have held back Duan Gong and his colleagues." Yu Yuncheng first took the responsibility on himself. He is such a down-to-earth person.

Old Duan's cunning is all about tricks, but he is also very honest when it comes to business: "No, no, no, this has nothing to do with Old Yu. Graphite is our main business. Old Yu is using his new technology to help us. This result is mainly caused by our own lack of ability in our own professional direction." Gao Zhendong waved his hand: "Isn't this good? What are you fighting about?"

No, we heard you were dissatisfied, and that means you were unsure, Lao Duan was complaining wildly in his heart.

Yes, Chief Engineer Gao has high demands on himself, but not as high on us. That’s no problem, Old Duan became happy again.

Ever since he suggested that they make pyrolytic graphite, Gao Zhendong had prepared a patent and some related knowledge in his head. He thought about it and had a rough idea in his mind.

He looked up at Yu Yuncheng and said, "Let's solve the problems one by one. Old Yu, is your pyrolysis temperature not over 1000℃?"

Old Duan felt much relieved. "One by one," meant that Chief Engineer Gao had seen many problems in this regard, and he was capable of solving them to a certain extent.

But Yu Yuncheng’s eyes widened. As expected, as expected.

Chief Engineer Gao is well aware of every technology he proposed, and can even know the details of his preparation just by looking at the inspection report.

"Yes, 950℃. I have analyzed that this temperature should be enough to thermally decompose the carbon in the hydrocarbon gas." Yu Yuncheng is researching chemical vapor deposition. In this regard, his decision-making power in technology is obviously higher than that of Lao Duan and others.

Gao Zhendong laughed: "Do you think the density of this 'pyrolytic graphite' is a bit low, or even lower than the roasted graphite made by Lao Duan and his team?"

Ok?
"Chief Engineer Gao, do you mean that the pyrolysis temperature is low?"

Gao Zhendong nodded: "Yes, it will also pyrolyze at 950℃, but the result of pyrolysis deposition is not pyrolytic graphite, but something else - pyrolytic carbon."

"Oh no!" Yu Yuncheng cried out. This thing called elemental carbon is indeed a ridiculous thing. It can be soft or hard, and under certain conditions, the soft and hard states can be transformed. Therefore, the results of preparing elemental carbon under different conditions are also very different.

"Then should we increase the temperature?" Once the cause is found, the problem can be easily solved.

"Well, at least above 1400°C. You should be prepared for the possibility of around 2000°C."

"I see." This is easy. Isn't it just a matter of burning the substrate to 2000℃? No problem. Type B thermocouple can even directly control some sections of it. If the temperature is higher, there are plenty of ways to do it.

But Gao Zhendong's next sentence made him realize that there was a problem from the beginning.

"Are you using the method of directly heating the substrate?" Gao Zhendong asked with a smile.

The substrate can be considered as the foundation for depositing pyrolytic graphite.

"Well, yes. Mr. Gao, how did you know?" Direct heating of the substrate used for deposition is the simplest heating method, which can be done by direct electrical heating.

However, as one of the countless heating methods, Chief Engineer Gao was able to guess what method they were using without even looking at any process documents. If it wasn't so unreliable, they would even suspect that Chief Engineer Gao was monitoring them every day.

Gao Zhendong nodded: "It's a big problem. This method is fine for experiments, but it won't work for mass production. Just from the size and thickness, I can guess that you used this method. Whether it's deposited pyrolytic graphite or pyrolytic carbon, do you think they will hinder the conduction of heat? As the thickness of the deposited layer increases, will it affect the deposition of pyrolytic graphite?"

He smiled and added the most important evidence: "And this is actually very obvious, as the more obvious the anisotropy, the thinner the sample thickness."

Gao Zhendong's words woke Yu Yuncheng up from his dream. He patted his head and said, "Oh! Yes, if this thing is well made and can show anisotropy of thermal conductivity, then the better the anisotropy, the worse the thermal conductivity to the sample surface, and the more it affects the pyrolysis and formation of the sedimentary layer! No wonder the more anisotropic it is, the thinner it is! Oh my! Such an obvious hint, I didn't notice it!"

At this time, his admiration for Gao Zhendong had reached a level that was beyond words.

This scene stunned Old Duan who was standing by. He had known that Chief Engineer Gao was capable, but he didn't expect him to be so amazing!

"Chief Engineer Gao, what should be used to heat it?" Ask for the answer directly!

Gao Zhendong said to Yu Yuncheng, "We are from the 17th Machinery Department. There is something you should use a lot - the medium-frequency induction furnace. As long as the reaction vessel is designed properly, the heating effect of this thing is much better than directly heating the substrate."

"Ah? A medium frequency induction furnace, isn't that used to make steel?"

Gao Zhendong had an expression that said "yes, that's right": "Yes, but it's also very good to use it here to refine carbon, hahahaha."

As for tools, as long as they are suitable, they can be used.

"Yes, yes, this is good. It can evenly heat the gas in the reaction vessel to a relatively consistent temperature, and it is not affected by sediments, so large-sized products can be obtained."

Just a slight improvement in the heating tools and methods solved the problem of being unable to produce large-area, thick products by directly heating the substrate.

(End of this chapter)