Chapter 554

It's not only Professor Zhao who has such feelings, but also Tong Xia and Wu Ping.

As long as it is engaged in helicopter, there is no one who does not care about the performance of the bearing. As long as he cares about the performance of the bearing, he will not be unaware of the excellence of the silicon nitride bearing.

You know, in addition to the chronic heart disease, the biggest difficulty in the domestic helicopter field is the high-end bearing.

This is also why we need to introduce relevant technologies from abroad, that is, we want to improve our own level in one step. From the effect point of view, some technologies do achieve the effect, but those high-end core technologies are still unable to break through.

There is no other reason, just because the high-end core technology is not to get some samples, do a physical and chemical analysis can be done according to the gourd, but need the accumulation of a number of basic disciplines, slowly groping to gradually form their own things.

In other words, there is no shortcut for these high-end technologies.

For example, the turboshaft engine on the helicopter, as the auxiliary turboshaft 8 of the imported "dolphin" helicopter, can be gradually localized according to the French technical indicators, but that is localization. If you want a more powerful turboshaft engine, the manufacturers of turboshaft 8 can not borrow much from the convenience of turboshaft 8, so they still have to start over.

Because the test of aeroengine is a basic skill and accumulation, and there is no room for any opportunism. Only by going through all the processes step by step can we say that we have completed the first step of the long march.

It's the same with the balls in high-end bearings. Although they are not attractive, the polishing of any stone is not inferior to those balls in appearance, but it involves extremely high-end materials science and manufacturing technology.

Take silicon nitride bearing as an example. We all know it's good. But in the world, besides the large-scale application of silicon nitride bearing to helicopter field in the United States, Europe and the Soviet Union are also developed in aviation technology, but there is no large-scale application. Why? It's not because it's hard to build and can't be used on a large scale.

But it's such a high-end thing. Tengfei group is actually called the product of the failure of the experiment. It's just a small thing for pocket money. My God, what kind of Freak is this Tengfei group!

Fortunately, Tong Xia and Wu Ping just think about it in their heart. If they are listened to by Zhuang Jianye and Liu Chun, they will definitely point the sky and paint the earth and swear that they are not cheating.

Because silicon nitride is really something that failed in the experiment of Tengfei aviation technology R & D center.

As for the experiment, it's high-end. The thermal insulation material outside the warhead of a long-range missile.

You know, Tengfei aviation technology R & D center has only done one thing for so many years, that is, carbon fiber reinforced composites derived from carbon fiber materials is one of the major branches.

One is carbon fiber reinforced metal matrix composites which have been widely used in aerospace field, and the other is carbon fiber reinforced ceramic matrix composites.

The former can be used as the main material of aero-engine or long-range missile body, while the latter is the necessary technology for aero-engine combustion chamber, turbine blade and other key components to lift and long-range missile to load warhead.

As we all know, the only way to improve the performance of aero-engine is to increase the temperature in front of the turbine and increase the thermal efficiency. However, the general metal materials can not adhere to the high temperature of more than 1000 degrees for a long time. Even if various means are used to increase the cooling efficiency, there is always a limit.

So the engineers thought, can we apply a layer of heat-resistant material on the heated parts of aero-engine, so as to increase the working temperature of combustion chamber, turbine and turbine blade?

In this way, high-end ceramic materials will enter the field of vision of aero-engine engineers, because the stiffness and strength of ceramic materials are good, and the key is that the heat resistance of ceramic materials is very good, generally between 1800 and 2000 degrees Celsius. Combined with the technical means of increasing the temperature in front of the turbine in the past, and with the ceramic coating, the performance of aero-engine will be greatly improved.

The same is true for the long-range missile's loaded warhead. Due to the friction with the air in the atmosphere when it falls at a high speed, it will generate a lot of heat energy. Without protection, the warhead will be directly burned by the atmosphere like a meteor before it hits the target.

In the past, alloy steel was used with thermal barrier coating to resist the high temperature of re-entry.

But in this way, the weight of warhead will be increased, the load of weapon will be reduced, and the attack efficiency will be reduced. Therefore, major countries in the world have carried out research on lightweight heat-resistant materials in order to apply them to the loaded warhead, so as to improve the load of weapon.

As an important material provider in the aerospace sector, Tengfei aerospace technology research and development center, like other material research institutions in the aerospace sector, undertakes the research in this field.

Based on their own advantages, they quickly developed a carbon fiber reinforced ceramic matrix composite scheme, and developed four types of carbon fiber reinforced ceramic matrix composites in the past year.

After the technical verification of the Aerospace Department, carbon fiber reinforced ceramic matrix composites based on zirconium borate and silicon carbide have become new long-range missile loaded warhead materials, and zirconia and silicon nitride have been recovered.

If other research and development units make a record of the failed products, they will be thrown into the pile of old paper and become the so-called "technical reserve".However, Tengfei aviation technology R & D center is not an ordinary technology R & D unit after all. The benefits brought by years of technological achievements transformation have long been deeply rooted. What's wrong with the failed products that were beaten back by the Aerospace Department? Can't they be reused?

Can't you use thermal barrier materials for aerospace? Can't you use your own aeroengine? So it was another half year's sullen research. It was found that zirconia could be used as coating material for engine combustion chamber and turbine blade to improve the thermal efficiency of aero-engine before turbine. The group strongly supported it, and the money was splashed in like rain.

In contrast, silicon nitride is not so lucky. Due to the property problems, the silicon nitride coating is easy to fall off during operation, and can not be used as the core material of aero-engine. Naturally, the attention will be reduced to the first level, and it will not get the full support of the group.

However, if it is wasted like this, the R & D center of Tengfei aviation technology is not very willing. After all, it has been working for such a long time. If it doesn't make a profit, it is too bad. Therefore, according to the nature of silicon nitride, the R & D Center of Tengfei aviation technology changed it into the main material of machine tools, cutting tools and bearings, and sold it to each branch factory according to the internal pricing mode of the group.

Liu Chun came here this time to listen to people from other branches say that the machining tools and bearings made by Tengfei aviation technology R & D center are not bad. He came here to see if their aviation power plant can use them.

But I didn't think that because of the good performance of the machining tool, I didn't get it myself. I only made two bearings and prepared to take them back for testing to see where they could be used.

In any case, I didn't expect that the low-end products of Tengfei aviation technology research and development center can make the old professor of Beihang react so much. Is it difficult for Tengfei aviation technology research and development center to make something extraordinary again?

"Brother Zhao, don't get excited. We have to test the progress of this thing. If not, aren't you happy in vain?" Looking at Professor Zhao's suspicions about life, Liu Chun was also startled, and quickly began to comfort him: "what's more, the bearing is still welded with two low carbon steels, which is not solid in casting."

"Welding?" Professor Zhao finally regained his mind and put the steel ring in front of his eyes. However, his eyes almost sank in and he could not find the weld. He asked, "what welding technology do you use?"

"Laser welding." Liu Chun said with indifference.

"What?" Professor Zhao's tone has changed