Before he finished speaking, Zhuang Jianye picked up a component on the table and added: "Of course, if we can control the cost of the kinetic energy interceptor of the Lyj-18 missile to 8 million yuan, it must be easy to use such as DL-520 and DL-527. Two sets of three-dimensional knitting machines were put into production"
¡°With that said, Zhuang Jianye took this opportunity to introduce the two sets of three-dimensional knitting machines in front of the army chiefs and leaders at the scene.
Among them, the three-dimensional knitting machine model composed of three circular structures is dl-520. There are 2,400 carbon fiber spindles distributed around each circle. It can produce circular windows and short structural trusses in aircraft under program control; aerospace Structural girders, brackets, brackets and other components in the container.
The model of the three-dimensional knitting machine composed of two square matrices is dl-527. Each square matrix can increase and decrease the number of internal spindles according to different needs. Currently, 5,000 spindles are installed in the room-shaped matrix used in workshop No. 5. It is precisely because of this that the DL-527 can produce larger components.
For example, aircraft can not only produce important load-bearing structural components such as skin frames, keel beam frames, and special-shaped frames, but also core structural components such as landing gear, helicopter flexible beams, and main structural components in the center of the propeller hub.
Not to mention the application in spacecraft, take the kinetic energy interceptor of the Lyj-18 missile as an example, the kinetic energy interceptor casing, the foreign currency in the internal fuel tank, the tail nozzle, connector and support ring of the small rocket vector engine , the support plate of the high-sensitivity infrared detector, and the bracket of the laser communication receiver are all made of dl-527.
However, whether it is dl-520 or dl-527, they produce the same thing, which is three-dimensional woven composite materials.
?Also known as true second generation composite materials.
Yes, you read that right. The so-called t300, t500, and t700 carbon fiber composite materials currently in the world are just evolved versions of the first-generation composite materials and are far from being called the second-generation composite materials.
The reason is very simple, that is, the preparation method of these composite materials is flat application. Whether it is connected with resin materials and cured at high temperature, or using an automatic wire laying machine to wind them layer by layer according to the mold, the root of this type of composite materials is layering. of.
This kind of layered processing brings an insurmountable drawback, that is, the specific strength and specific modulus in a specific direction cannot achieve satisfactory results; the layered structure also leads to Composite materials are prone to oxidative delamination in high-temperature environments, which affects the safety of the entire aircraft.
Because of this, although carbon fiber composite materials such as T300, T500, and T700 have been around for more than 20 years, and various metal matrix composite materials based on them are also very mature, these composite materials still cannot become the main structure in the aviation and aerospace fields. The main reasons are trusses, keel frame beams, landing gear, and high-temperature and heat-resistant components.
Because the layered paving structure cannot make composite materials achieve the consistency and compactness of traditional metals, let alone high-temperature and heat-resistant components, the oxidation delamination phenomenon cannot be overcome at all.
In the early years, the carbon-carbon composite material of the anti-ship ballistic missile re-entry warhead undertaken by China Tengfei led to several test failures for this reason.
This non-carbon composite material cannot withstand high-temperature burning. Instead, the molecular structure of the epoxy resin completely fails under the action of high temperature during the layer-by-layer paving process, causing the paving layers to peel off and finally directly burn through the entire warhead.
There are two ways to solve this problem. One is to increase investment in chemical research and development and develop a new epoxy resin material that can withstand high temperatures of 2,500 degrees Celsius to overcome the super high temperature on the surface of re-entry warheads at hypersonic speeds.
The other is to directly skip the complicated first-generation composite material process and enter the second-generation composite material, completely abandoning the traditional layer-by-layer composite manufacturing process, and using a method that breaks the tradition to combine composite fibers in The prefabricated parts you want to manufacture are directly made by intertwining each other, thereby forming a new three-dimensional composite material.
Compared with the first-generation layer-by-layer composite materials, the second-generation three-dimensional composite materials have many benefits. The most important point is that this composite material can fully utilize the excellent performance of carbon fiber. It can achieve excellent specific strength and specific modulus in all directions. Because of this, the second-generation three-dimensional composite material fully meets the quality requirements of the main load-bearing structure of the aircraft, and can thus replace metal in large quantities. Become the main driver of aircraft weight reduction.
In addition, three-dimensional composite materials also show excellent performance in high temperature resistance and can withstand temperatures up to 2387 degrees Celsius. Based on this three-dimensional composite material, they can be widely used in aerospace engine combustion chambers and turbine blade bases. , tail nozzles; and important heat-resistant areas such as engine tail nozzles, connectors, and high-temperature resistant warhead casings in the aerospace field.??.
??The same carbon fiber products are actually so fundamentally different, and thus divided into two generations. This seems a bit incredible to outsiders, but it is not difficult for insiders to understand.
This is like building a house. Layers of bricks are stuck together to make it strong. It is not as strong as building various structures, frames, girders and dampers inside.
Three-dimensional composite materials belong to the latter complex structure, which uses the toughness and plasticity of fibers to weave a series of complex structures into them through complex array arrangements to form strong prefabricated parts.
This method sounds simple, as if you only need to understand the principles of the loom to give it a try.
However, the reality is far from being as simple as imagined. If one can create a three-dimensional weaving machine for producing second-generation composite materials by understanding the principles of the loom, then New Delhi, Bangladesh, Egypt and Myanmar, which are major textile countries, should join the ranks of developed countries. Rather than just suffering at the low end and hoping for food from Western masters.
In fact, there is only one country in the world that has mastered the second-generation composite material technology, and that is the United States. They started research in this area in the mid-1970s, and achieved preliminary results in the mid-1980s, and then the Atlantic Machinery Equipment Company of the United States realized practical use. ization and quickly spread among research institutions and aviation giants such as NASA, Boeing, and Lockheed Martin, thus placing the level of U.S. aerospace manufacturing at a large distance from the world average.
It is no exaggeration to say that the U.S. national missile defense system, theater missile defense system, stealth combat aircraft, new generation strategic transport aircraft, and stealth strategic bombers can be developed and quickly put into service, which is inseparable from the widespread application of second-generation composite materials. This has also become an important symbol of American aviation hegemony.
Now, with the putting into use of China's take-off related equipment, to a certain extent, it is tantamount to obtaining a ticket for this type of aviation hegemony!
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