Chapter 1349

Before the end of the speech, Zhuang Jianye picked up a part on the table and added: "of course, we can control the cost of kinetic energy interceptor of lyj-18 missile at 8 million yuan, and it has to be easy to put dl-520 and dl-527 three-dimensional knitting machines into operation..."

With these words, Zhuang Jianye took this opportunity to introduce the two sets of three-dimensional knitting machines to the leaders of the troops.

The model of three-dimensional braiding machine is dl-520, which is composed of three circular structures. There are 2400 carbon fiber spindles around each circular structure. It can produce circular porthole and short truss beam in aircraft under program control; The truss beam, bracket, bracket and other components of spacecraft.

The model of three-dimensional braiding machine composed of two square matrices is dl-527. Each square matrix can increase and decrease the internal spindles according to different demands. At present, 5000 spindles are installed in the room matrix used in workshop 5. Because of this, dl-527 can produce larger components.

For example, aircraft can not only produce skin frame, keel beam frame, special-shaped frame and other important load-bearing structural components, but also bear core structural components such as landing gear, helicopter flexible beam, main structural components in the center of hub.

As for the application of spacecraft, let alone the kinetic energy interceptor of lyj-18 missile, the shell of kinetic energy interceptor, the foreign currency of internal fuel tank, the tail nozzle, connector and support ring of small rocket vector engine, the support plate of high sensitive infrared detector and the bracket of laser communication receiver are all made of dl-527.

However, no matter dl-520 or dl-527, they all produce the same thing, which is 3D braided composite.

Also known as true second generation composites.

Yes, you are right. At present, the so-called T300, t500 and T700 Carbon Fiber Composites in the world are only the evolutionary version of the first generation of composites, far less than the second generation of composites.

The reason is very simple, that is, the preparation methods of these composite materials are planar. Whether they are connected with resin materials, cured at high temperature, or wound layer by layer according to the mold by automatic wire laying machine, the roots of these composite materials are layered.

However, this kind of layered treatment brings an insurmountable disadvantage, that is, the specific strength and specific modulus in a specific direction can not achieve satisfactory results at the same time; The layered structure also leads to the oxidation and delamination of composite materials in high temperature environment, which affects the safety of the whole aircraft.

Because of this, although T300, t500, T700 Carbon fiber composites have been born for more than 20 years, and all kinds of metal matrix composites based on them are also very mature, in the field of aviation and aerospace, these composites still can not be the main reasons for the main structure truss beam, keel frame beam, landing gear, high temperature and heat resistant parts.

Because the layered structure can't make the composite material reach the consistency and compactness of traditional metal, let alone the high temperature and heat-resistant parts, the phenomenon of oxidation delamination can't be overcome.

In the early years, China Tengfei undertook the carbon carbon composite material of anti-ship ballistic missile reentry warhead, which led to several test failures for this reason.

The non carbon carbon composite can not resist high temperature burning, but the molecular structure of epoxy resin in the layer by layer paving process is completely invalid under the action of high temperature, resulting in the peeling off of the paving layer, and finally directly burning through the whole warhead.

There are two ways to solve this problem. One is to strengthen the investment in chemical research and development, and develop a new epoxy resin material that can resist the high temperature of 2500 degrees Celsius, which can be used to overcome the super high temperature of the reentry warhead surface under hypersonic conditions.

The other is to go directly beyond the complex first generation of composite technology and enter the second generation of composite materials, completely abandon the traditional process of layer by layer composite material manufacturing, and use a way to break the traditional way to make the preforms directly under the mutual winding of composite fibers, so as to form a new three-dimensional composite material.

Compared with the first generation of layer by layer composite materials, the second generation of three-dimensional composite materials have many advantages. The most important point is that this kind of composite materials can give full play to the excellent properties of carbon fiber, and can achieve excellent specific strength and specific modulus in all directions. That's why, The second generation of three-dimensional composite materials fully meet the quality requirements of aircraft main bearing structure, which can replace a large number of metals and become the main driver of aircraft weight reduction.

In addition, the three-dimensional composites also show excellent performance for high temperature resistance, and can withstand the high temperature of 2387 degrees Celsius. Based on this, the three-dimensional composites can be widely used in aero-engine combustion chamber, turbine blade base and tail nozzle; As well as the aerospace field of engine tail nozzle, connector and high-temperature warhead shell and other important heat-resistant fields.

The same carbon fiber products, actually have such essential differences, and thus can be divided into two generations, which makes outsiders seem a little incredible, but it is not difficult for professionals to understand.

It's like building a house, one layer at a time, glued with bricks. It's not as strong as building all kinds of structures, frames, trusses and dampers inside.

Three dimensional composite materials belong to the latter complex structure, that is, by using the toughness and plasticity of fibers, a series of complex structures are woven through complex array arrangement, so as to form a solid preform.

This method is simple to say, as if as long as you know the principle of the loom, you can give it a try.

However, the fact is far from simple. If you know the principle of loom, you can produce the second-generation three-dimensional braiding machine for composite materials. New Delhi, Bangladesh, Egypt and Myanmar, as big textile countries, should be among the developed countries, instead of waiting for the Western masters to enjoy their food at the low end.

In fact, there is only one country in the world that has mastered the second generation of composite technology, namely the United States. They started their research in this field in the mid-1970s, and achieved preliminary results in the mid-1980s. Then Atlantic mechanical equipment company of the United States realized its practical application, and quickly launched its research in NASA, Boeing, IBM, etc Loma and other research institutions and aviation giants are spreading out, so that the US aerospace manufacturing level is rapidly away from the world average.

It is no exaggeration to say that the US national missile defense system, theater missile defense system, stealth combat aircraft, new generation strategic transport aircraft and stealth strategic bomber can complete the research and development and quickly serve without the wide application of the second generation composite materials, which has also become an important symbol of US aviation hegemony.

And now, with China's take-off related equipment put into use, to a certain extent, it is also equivalent to getting the ticket of this kind of aviation hegemony!