Thermal spraying is a material processing technology. Its principle is to cover a substrate with a coating to change certain aspects of the substrate's properties. What materials are used as coatings is very particular. Different materials can achieve different results.
For example, titanium nitride coating can improve the wear resistance of the material, while zirconium oxide coating can not only be wear-resistant, but also play a role in high temperature resistance.
As a materials scientist, Qin Hai has some understanding of the properties of various materials. As soon as Leng Yuming said that the material the customer wanted to coat was ferrite, he knew who the customer was, because at least in that era
, The main function of ferrite material as a material coating is to absorb radar waves, and those who need this function can only be the military.
The use of ferrite coatings to achieve the stealth effect of aircraft and other equipment was a very common practice at that time. Although it is a military secret of various countries, some clues can be seen from some documents. In the field of engineering in our country
The scientific researchers learned about this technology from some fragments of foreign literature and started related experiments. As a time traveler, Qin Hai knew the development history of this technology and its various flaws.
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The so-called ferrite refers to various types of compounds formed by the combination of iron and oxygen. The chemical formula of spinel ferrite includes a divalent metal ion, such as divalent manganese, cobalt, nickel, copper, etc.
; Two trivalent metal ions, usually ferric ions; and four oxygen ions.
Using spinel ferrite as the absorbing material has a relatively simple process and relatively low price, but its disadvantage is that the density is too high and the absorbing frequency band is too narrow. If you want to increase the absorbing bandwidth, you need to use more
Each coating is for a frequency band, which makes the coating too thick and increases the weight of the equipment.
For example, the specific gravity of ferrite material is about 5. If the coating thickness is 4 mm and the coating area is 50 square meters, then the weight of the entire coating can reach 1 ton, which is undoubtedly for a stealth aircraft.
It's an unbearable additional burden.
Qin Hai did not specialize in the research of stealth materials in his previous life, but he had participated in some peripheral consulting work and had some understanding of some major technical direction issues. He knew that focusing his research on ferrite materials was a detour.
, so I couldn’t help but want to remind myself of these colleagues.
Li Zhongyun and Wu Honglin are naturally not engineers from Tongjiang Mining Machinery Factory. Their real identities are researchers from the 70x Institute of Military Industry, who are conducting research on stealth materials for stealth fighters. The current research ideas of the 70x Institute for stealth materials are:
It is also limited to the use of spinel-type ferrite materials. The researchers purchased three thermal spray machines from the Qingfeng Agricultural Machinery Factory through the Mining Machinery Factory to conduct spraying experiments on ferrite materials. The results found that the adhesion of the materials was not enough.
But I couldn't solve this problem myself, so I took this trip to Qingfeng Factory.
According to Li Zhongyun and Wu Honglin's original thoughts, they just went to Qingfeng Factory to understand the technical details. There was no need for Qingfeng Factory's technical personnel to actually get involved in this research. After all, this was a confidential project involving the national defense industry and could not be carried out easily.
The private sector was invited to participate. Who would have expected that Qin Hai would categorically say that they were on the wrong track as soon as he came up. He also said such suggestive words as "employers without doubt", so they had to take it seriously.
After the two left the Qingfeng Factory, they called the leader of the unit and talked about the situation. There happened to be a researcher from the 70x Institute who came to the missile base in Anhe to participate in the missile tail diagnosis work, and knew who Qin Hai was.
, After saying this, the unit leader immediately instructed Li and Wu to go to the provincial military region to contact Yue Guoyang in order to fully understand Qin Hai's background.
After listening to the two men's accounts, Yue Guoyang immediately patted his chest and said that Comrade Qin Hai was trustworthy. A few years ago, the Political Department of the Provincial Military Region had screened his political background, and in recent years, his business has grown more and more.
The bigger it is, the less likely it is to get together with foreign hostile forces. Regarding Qin Hai’s assertion that ferrite spraying is a wrong approach, Yue Guoyang laughed and told Li and Wu that Qin Hai’s attainments in materials science
It's unfathomable. If they have difficulties, finding Qin Hai is the best way.
With a skeptical attitude, Li and Wu returned to Qingfeng Factory and asked to meet Qin Hai. In their opinion, if Qin Hai could accurately tell their origins, it would prove that Qin Hai did understand the invisibility materials.
It is indeed possible to provide them with help. If Qin Hai guessed wrong what they were doing, there would be no need to talk about the rest of the matter.
"Chairman Qin, we didn't know your situation before, so we kept some things secret from you. Can you understand this? You are right. We are engaged in aircraft stealth materials. Why do you think ferrite is
Is spray painting a wrong approach? Isn’t this what foreign aircraft and missile stealth technology uses?" Wu Honglin asked.
Qin Haidao: "Because our factory is engaged in thermal spraying equipment, I have paid a little attention to this technology. You are right. Ferrite materials are indeed used as aircraft stealth materials abroad.
There are not many documents, but some clues can be gleaned. However, as far as I know, the use of ferrite materials as stealth materials can only be regarded as the first generation of stealth technology. Ferrite materials have shortcomings in stealth, and you must be the same.
clearly."
"We are working hard to overcome these defects. We use the thermal spray process, which is also an attempt." Wu Honglin said.
Qin Hai nodded and said: "Yes, from the literature, the foreign method is to mix epoxy resin and ferrite materials to make paint for surface coating. You use thermal spraying method, which can improve the coating quality.
Strength, and reducing the use of resin, is indeed an improvement and deserves recognition."
"..." Li Zhongyun and Wu Honglin were speechless. If Qin Hai's words had come from the mouth of the director, they might have been a little excited, but such a young man said it so arrogantly in front of these two experts.
What is "worthy of recognition" seems a bit weird.
Qin Hai didn't care about their emotions. He was not as professional as these two when it came to making stealth materials, but when it came to understanding future technological trends, he was enough to be their teacher.
"The defects of the ferrite material itself cannot be completely compensated by changing the coating process. Therefore, other stealth materials are currently being studied abroad. According to my judgment, ferrite materials will be completely replaced in the future. We are currently spending
Too much energy is spent on ferrite materials, and the final result can only be that we will always fall behind. Since we know that other materials are more promising, why can't we use limited manpower and financial resources in these areas?" Qin Hai said generously
Chen Ci said.
Li Zhongyun and Wu Honglin exchanged a surprised look, and then asked tentatively: "Chairman Qin, you think ferrite materials must be outdated, so do you know what materials will be used in future stealth technology?"
"I don't dare to say that I understand it. I just have some personal opinions, which can be considered as a way to attract others." Qin Hai said, "According to my analysis, microwave stealth materials can be divided into two categories. The first category is inorganic materials, including various metal powders, metal
The second category is organic polymer materials, including various conductive polymer materials, such as polyethylene block, polyaniline, polypyrrole, polythiophene, etc., as well as organic metal complexes, etc.
In the long run, organic polymer materials are more promising because they have better plasticity. After adding various dopants, they can absorb waves with a large bandwidth, and their specific gravity is much lower than that of ferrite materials.
Effectively reduce the weight of the aircraft."
After Qin Hai said this, Li Zhongyun and Wu Honglin were dumbfounded. They had seen some clues about the situations Qin Hai mentioned from some foreign documents, but they were far less clear than what Qin Hai summarized.
As soon as they said it, they knew that these words were definitely not groundless. Their understanding of stealth materials was already better than those two experts.
Since Qin Hai had already planned to help the other party, he didn't bother to hide anything anymore. These general ideas are sometimes just a layer of window paper. When he didn't click on it, he felt mysterious and unpredictable.
The discovery was nothing more than that. If Li and Wu wanted to investigate where his knowledge came from, he could point them to a few public documents for them to read carefully. If they could not read what Qin Hai said from them,
, it can only be blamed on their lack of academic sensitivity. Who can explain clearly such things as sensitivity?
"Chairman Qin, what you said is great. Can you go back with us? I think we, Mr. Gu, will definitely have a lot in common with you." Wu Honglin said excitedly.
Qin Hai was stunned for a moment and asked: "Chief Engineer Gu? It can't be Teacher Gu Qinyuan, right?"
"Exactly, how come Chairman Qin knows our Chief Engineer Gu?" Li Zhongyun said in surprise.
"Uh-huh, we've been friends for a long time, but we just haven't had the opportunity to meet each other." Qin Hai quickly covered it up. This Chief Engineer Gu is also considered a great person in the material industry, but because he has been in the military industry system, many of his achievements cannot be published in academic publications.
, so his reputation in society is not very great. Qin Hai had dealt with him several times in the previous life. As for this life, he had also heard of this name from Chen Heqian, so it is reasonable to say that he has a divine connection.
Li Zhongyun said: "Both of us are Mr. Gu's assistants. This time, it was Mr. Gu who asked us to come here. Two days ago, we called back and told you about your situation. Mr. Gu was very interested in your views and explained
We want to ask you for advice. I didn’t expect Chairman Qin to have such a thorough understanding of stealth materials, so we would like to take the liberty of asking you to meet our chief engineer. He must also have many questions to discuss with you." (To be completed.)
Continued…)
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