In the engine, the role of the blade is very important, and in the working process, the blade is subject to centrifugal force, air aerodynamic force, thermal stress, alternating force, random load, etc., under the action of various loads, the blade High-cycle fatigue, thermal fatigue, and low-cycle high-stress fatigue damage are easily caused.

If the blade is unqualified, parts will be sprayed continuously after being mounted on the bench, and a fragment will fly out at high speed, which is enough to cause an accident.

This kind of scene, I don't know how many incidents happened in the later generation of Han Guo's engine development.

Now, even with the success of Spey's research and development, it cannot guarantee the smooth development of the new generation of engines.

The materials of the blades are aluminum alloy, stainless steel, titanium alloy, superalloy and composite blades and so on. The specific selection of materials should consider multiple factors such as working temperature, strength, condition and weight.

In contrast, economy is the last thing to consider. The previous turbojet engines in Han Dynasty used stainless steel or aluminum alloy compressor blades, but now, titanium alloys have been used.

Titanium alloy, because of its low specific gravity, high specific strength, corrosion resistance, and outstanding contribution to weight reduction, so it is widely used in the aviation field. Take the current F-11 fighter plane, the amount of titanium alloy used on it has greatly increased.

In addition to the materials used, the shape and processing technology of the design are also very different.

The initial fan blades were limited by manufacturing technology and were solid, narrow-chord, and damped boss structures. With the development of manufacturing technology, in order to improve the aerodynamic efficiency of the fan blades and reduce the weight of the fan, the solid structure is replaced with a wide chord, sandwich or hollow structure. Spey’s engine blades are solid, just using the precision casting process. The core engine of the new third-generation machine supposedly adopts a hollow titanium alloy structure. Unfortunately, because the processing technology is not enough, and the cost is The consideration led to Wu Lao still using the blade processing technology on Spey.

The processing technology has not changed, but the style of the designed blade has also changed, which naturally fails to meet the requirements.

Titanium alloys have extremely high yield strength at room temperature, poor plasticity, and are prone to springback. Most of the engine blades formed by conventional metal processes are difficult to ensure the dimensional accuracy, and they are time-consuming and labor-intensive, and their performance cannot be guaranteed.

This calls for the arrival of new processes, and superplastic forming/diffusion welding technology is a combined processing technology developed by using the good solid-state bonding properties of materials in a superplastic state.

This process can take advantage of the excellent superplasticity and diffusion connectivity of titanium alloys to manufacture titanium alloy multilayer structures, saving about 30% to 50% in cost and weight. It can save man-hours, save raw materials, improve efficiency, and process weight. Various structural parts with light weight and good structural rigidity.

Superplasticity usually means that the material exhibits exceptionally high elongation without shrinkage and fracture under certain tensile conditions. When the elongation is greater than 100%, it can be called superplasticity.

Diffusion bonding is to press two or more solid phase materials together, place them in a vacuum or protective atmosphere and heat them to a temperature below the melting point of the base material, and apply pressure to them to cause microscopic plastic deformation of the microscopic unevenness of the connection interface. Close contact, and then through heat preservation and mutual diffusion of atoms to form a strong metallurgical bond.

Why can Spey be exported to Han? Because Spey is the engine of Niu Guoren's previous generation, its thrust-to-weight ratio is only 5. Since it has fallen behind, of course it can make money by exporting.

But how can these most advanced technologies that have just been developed be given to Han?

"If we want to realize this latest technology, we need diffusion bonding-superplastic forming equipment, diffusion bonding heating equipment, diffusion bonding-superplastic forming vacuum equipment. As long as I have these equipment, I can operate it." Robert said.

He also knows the difficulties. It would be better if Han imported these equipment from abroad.

"At the same time, the superplastic forming temperature of titanium alloy is 850~980℃, and the temperature of diffusion bonding is 870~1280℃. Because the temperature during superplastic forming meets the temperature conditions of diffusion welding, and both need to be in a vacuum or It is carried out in a protective gas, so the two processes can be combined to complete the superplastic forming and diffusion bonding process in one heating and pressurizing process. I had thought of doing this a long time ago, but the bricks of Rolls-Royce are afraid Defective products were produced but were not adopted."

This is not something that can be done with CNC machine tools. Advanced CNC machine tools only improve the machining accuracy. The manufacture of titanium alloy blades requires an updated process. It is not made from a car, but is directly superplasticized in this way and then diffused. from.

Qin nodded his head and suddenly thought of something. This is very simple. How are the blades of the F404 engine processed? Will the same process be used?

Especially, is the engine production line also responsible for the production of such blades?

Fighters have countless parts, and the production line is just the final assembly line, but the engine is definitely not like this. After all, the engine is a high-tech product. You may purchase an accessory or something, but the main body of the engine must be produced on a production line. Even the blades of the engine have to be produced by other affiliated factories. Can engines be produced?

Thinking of this, Qin Guan made up his mind and said: "We must adopt new technology to achieve the surpassing of this third-generation machine. Since we are required to use this kind of blade, we will build it. As for the related equipment, we North Industries The company came to think of a solution.

Mr. Wu was immediately overjoyed. Since Qin Guan said to think of a way, he would definitely be able to figure out a way. If this kind of blade can be made, then the core engine of the engine will never fail if it is tested again.

As for now, this engine cannot be tested anymore, and we must wait for the arrival of new technology.

"Mr Qin, this kind of engine uses a lot of titanium alloy, I am afraid the price will go up." Wu Lao continued.

"No matter how high the price is, it is lower than we buy an engine? And, in this way, we will still control our destiny in our own hands, and will not be stuck by the engine again, Mr. Wu, let's talk about it in detail, except for the most important thing now. For high-thrust engines, we still have a strong demand for medium-thrust engines."

Mr. Wu took off his glasses and rubbed his eyes: "Yes, we still have a demand for middle push, Mr. Qin, but we can't be too busy."