Chapter 470

Looking at Song Changzheng's tension and excitement, director Zhao said with a smile: "of course, the intelligence of this aspect is more complete than what you need to grasp. Let me tell you something, if Trident II submarine launched missile does not have carbon fiber reinforced aluminum matrix composite, its range will be reduced by at least 20% to 30%, you know Well... "

Director Zhao stopped talking, even if he didn't, because he didn't know the specific parameters of the carbon fiber reinforced aluminum matrix composite used by the United States for Trident II submarine launched missile.

So we can only look at Zhuang Jianye. That's very obvious. Let's talk about your carbon fiber reinforced aluminum matrix composites, so that his brother won't be embarrassed again.

The customer's demand is Zhuang Jianye's unshirkable responsibility, so director Zhao's eyes cast on the moment, quickly put the words to the end with a smile: "the general titanium alloy specific strength is 1.1; the specific modulus is 102; I don't know what the American data is, but our carbon fiber reinforced aluminum matrix composite material's specific strength and specific modulus are three times of titanium alloy."

"So high!"

Li Fang's eyes widened as soon as he said this. He thought it was a little inconceivable. You should know that specific strength and specific modulus are common ratios in material science. They mainly show the absolute weight or pressure that a material can bear per unit volume, and also measure the structural strength of a material.

The larger the value is, the higher the strength of the material is and the less the unit usage is.

So these two values are the most critical data to measure materials in the aerospace field. There is no way. The aerospace field pursues materials with light weight and high strength.

In the past, titanium alloy was regarded as the handle of this kind of materials. Now, carbon fiber reinforced aluminum matrix composites instantly crush titanium alloy on key data. Li Fang, who specializes in materials and systems engineering at Naval University of engineering, is not shocked.

As a result, before Li Fang's surprised expression was completely released, Zhuang Jianye's next expression made him surprised again: "it's not high. With the characteristics of carbon fiber reinforced aluminum matrix composite, at most, it can be made into a d-50 gearbox. Of course, because it's light, the effect of weight reduction is very obvious, but the contribution rate is about 10%, after all, magnesium alloy Gold is light, too.

What really plays a key role are the other two materials. First of all, the silicon carbide fiber reinforced aluminum base material with specific strength and specific modulus five times higher than that of titanium alloy. Compared with the previous alloy materials, the silicon carbide fiber reinforced aluminum base material is lighter, with higher strength and better heat resistance. Therefore, the silicon carbide fiber reinforced aluminum base material is used as the core to make compressor blades Efficiency almost tripled, eh What is the pressure ratio of the improved hx-4-1 core compressor

This Zhuang Jianye asked Qian Qiang, Qian Qiang did not hesitate to reply: "from the previous 6 increased to 7.2."

Zhuang Jianye nodded and then said, "then there is the silicon carbide fiber reinforced titanium base material, which is also the most critical material for d-50 except turbine blade at present. The specific strength and specific modulus are six to eight times that of ordinary titanium alloy. In addition, the mechanical properties are still very good at temperatures above 800 ℃.

So this kind of material is used in combustion chamber, turbine disk, turbine guide vane and transmission shaft, which is the reason why silicon carbide fiber reinforced titanium based material is widely used. Although our d-50 is expanded to three meters long, its overall mass is controlled at 857 kg.

But it doesn't mean that the performance of our d-50 can't keep up. On the contrary, because of the application of a large number of metal matrix composites and the nickel based alloy turbine blades equipped with cooling system, the turbine front temperature of our improved hx-4-1 core engine has increased from 1000K to 1350K. "

"That's from 727 to 1077." Qian Qiang added.

"It's 300 degrees Celsius!" This is not only Li Fang, but also the song Long March.

Zhuang Jianye nodded with a embarrassed smile: "this is the limit of hx-4-1 core machine. In the next step, we are going to integrate the existing advanced materials on the basis of hx-4-1 core machine. The R & D cycle power is 6 MW, the air intake volume is 11, and the total temperature in front of the turbine is 1600K to 1650k, that is 1327 ℃ to 1377 ℃.

The current model name is tentatively determined as hx-11-6 core machine. On the other hand, based on d-50, we should continue to tap its potential and strive to launch gas power plants including turboprop, turbofan and power generation. Of course, if we want to achieve this, the most important thing is to solve the reliability problem of d-50 first. After all, the overhaul interval of d-50 is a little short, which is relatively short The gap between foreign similar products is obvious. "

The three of them were stunned. Director Zhao didn't have to say that he was still confused at the moment. He gave the conversation to Zhuang Jianye. Shouldn't he talk about carbon fiber reinforced aluminum matrix composites? How to say the topic is crooked? To the d-50?

Compared with Director Zhao's confused surprise, Li Fang and song Changzheng are really surprised. Although the navy is also eager for submarine launched missiles, the main body of submarine launched missiles is not dominated by the Navy, but the overall grasp of director Zhao's space Department. Therefore, the navy is eager for return, but can only wait passively.In contrast, the naval aviation power is the focus of the two people's attention. After all, from World War II to the present, the air supremacy must be obtained before the sea supremacy.

Therefore, the strength of the Navy's air force determines the level of the Navy's combat effectiveness, and the aero-engine is the indispensable core of the Navy's air force, which naturally attracted the attention of the two people.

But just because of this, Li Fang and song Changzheng were stunned by what Zhuang Jianye said. The temperature in front of the turbine actually reached 1077 ℃.

How much is a turboprop-6 of the same class? It's only 792 degrees Celsius.

It's 285 degrees higher.

What does that mean? D-50 still has potential.

Because the turboprop-6 at 792 ℃ has reached the level of 3000 kilowatts, increasing the d-50 at 285 ℃ is definitely more than that. You should know that the aeroengine's power improvement is to increase the temperature in front of the turbine. For every 100 ℃ increase, the power will increase by 20%. Compared with the turboprop-6, the d-50 will increase by 285 ℃, and the power should be increased by nearly 60%.

In other words, today's model of d-50 is just because the turboprop system does not give full play to its potential. If it is replaced by a turbofan with a large bypass ratio or a turbofan with a small bypass ratio, the effect will appear immediately.

According to the current turbine front temperature conversion, the d-50 of these two engines will have a thrust of 4 to 6 tons.

This data is amazing. You should know that the turbojet engine on the J-7 is at this level, but it's only on paper, and it's far from practical application. If the d-50 of Tengfei airlines can be changed into a small bypass ratio turbofan afterburner, will the J-7 make a qualitative leap?

Li Fang and song Changzheng constantly daydream in their minds. At this time, Zhuang Jianye said the most critical defect, reliability. The daydream immediately made a pause in their hearts. Li Fang immediately asked, "what is the overhaul interval of your d-50 today?"

Zhuang Jianye didn't speak, but looked at Qian Qiang. Qian Qiang sighed helplessly and said, "it's just 1860 hours."

This almost made Li Fang stagger, and he cried urgently: "such a high overhaul interval is also called poor reliability?"