Chapter 352 Bang, broken!
“This is called pressurized solid state recrystallization. The main driving force for grain growth comes from the interfacial energy of the polycrystalline formed after rapid quenching.”
Yu Yuncheng was a little agitated by these words. Confused, but regardless of all that, Gao Zhendong gave an explanation. He could just go back and read the book himself, although he might not be able to read it.
Seeing that Gao Zhendong is so certain, Yu Yuncheng is relatively optimistic about the credibility of this theory. At least this strange-sounding method is not completely without theoretical basis, although he does not understand this theory yet. , but it seems that at least Gao Zhendong understands.
Seeing that he had at least accepted the principle of this method, Gao Zhendong told him the details.
"When annealing a single crystal, it actually has nothing to do with the 'pull' action. The main reason why we chose this method is that it does not require a crystallization control mechanism, and the requirements for temperature control accuracy are not too high."< br>
This was an unexpected surprise for Yu Yuncheng. Pulling silicon monocrystals was like waiting for a baby.
It won’t work if the temperature is too high or too low; it won’t work if the temperature gradient is too big or too small; it won’t work if it is pulled too fast or too slow; it won’t work if it turns the crucible too fast or too slow
Hearing that this method did not require crystallization control, he suddenly felt like it was dawn. This method was a good choice.
Then he heard a not-so-good news. As Gao Zhendong said before, this thing is very time-consuming.
He needs to put the rapidly quenched and directionally solidified crystal ingot into an annealing furnace, or recrystallization furnace, and burn it for 7749. No, 30 to 45 days.
This annealing furnace is actually the pressurized stainless steel furnace Gao Zhendong told him just now.
“This process can eliminate the composition gradient at the microscopic level, and eliminate the dendrite-like structure you have observed, and the grains grow to form single crystals. In this process, the reaction tube or the mercury cadmium telluride compound The temperature should always be near its melting point, but it needs to be lower than the melting point, about 10 degrees, but it does not need to be controlled very accurately. "
That's it? Gone?
Yu Yuncheng felt very unexpected. Is this just fine? There are no other requirements.
After listening to his question, Gao Zhendong smiled and said: "Yes, there are no other requirements. Just stop when the time is up. The time can actually be optimized appropriately, but now we are doing research, so we require you to take it out every 5 days." Test a part of the sample to find out the relationship between time and crystal growth. Now our technical environment is poor and the conditions are insufficient. I think this method is the best. The requirements are simple, the crystal utilization rate is also high, and the composition is still very good. Uniform. ”
These characteristics are all optimal solutions in the current environment. Only by high crystal utilization can the price be reduced.
Yu Yuncheng was happy. For this experiment, all he needed was a well-built stove, hands, and time.
However, he still asked the question in his mind: "This method is so simple and the product is good, so what is the cost?"
Any technology advances amid trade-offs. Just like 5G technology, under the same conditions, if you want high speed, you must give up wide coverage.
Shannon's Theorem: You're right.
Gao Zhendong said: "This method cannot grow very large crystals. Generally, the diameter is no more than 15mm and the length is only a few centimeters, but it is enough. And there are some other problems, such as impurities. Regardless of the amount of impurities that enter the crystal, they will basically be melted into the crystal. At the same time, there are many defects at high temperatures, and the quartz tube itself may also form impurities in the crystal. But the important thing is that even so, as long as it is controlled well, then this "
In fact, no matter which method is used to prepare bulk crystals, cadmium mercury telluride cannot grow, so the defect of small crystals does not matter. It's just as bad, and the rest are not big problems at this stage.
Although I don’t know where Gao Zhendong’s confidence comes from, Yu Yuncheng was very excited when he saw what he said so categorically. From this point of view, in addition to taking longer, this method is still effective under the current conditions. It's really the most appropriate way.
Even if there will be repetitions in the experiment, for him, spending half a year and a year is not a big deal.
Although judging from Gao Zhendong's requirements, the main process of a test takes about 50 days. If it goes well, it will be completed in two months. However, with the modification of the pressurized furnace, possible repeated failures, etc., Gao Zhendong said at the beginning Half a year to a year is really not an exaggeration.
Yu Yuncheng, who got the materials for the next crystallization process from Gao Zhendong, came and went in a hurry and didn't stay for a few days.
No way, this project cycle is really long, every bit of time must be saved.
But before leaving, the comrades he brought with him used the single crystal furnace of the third rolling mill to haul another batch of silica away.
The dosage is relatively large and not enough.
By the way, they also took away a single crystal furnace approved by the ministry. That's right, as a participating unit of the single crystal furnace, they have just approved a single crystal furnace now.
Except for those required by Factory 1274, all the products produced in the past were put into production locally. They started work as soon as they came off the assembly line and participated in the work of pulling out the batch of silicon single crystals for the desert.
——
This is an era full of energy and enthusiasm. Gao Zhendong and Yu Yuncheng are busy, and similarly, others are not idle either.
In a laboratory of the Guangdong Research Institute, a rocket engine is fixed on the engine test bench.
This test bench looks very simple. If Gao Zhendong were to look at it, it would be hard to tell that it was an engine test bench without the engine on it. The image of this thing was similar to the fixed-fat test bench he had seen online in his previous life. The style difference is really huge.
But let alone soil, people can still measure the items that should be measured.
The diameter of the engine is just over ten centimeters, and it is slender and slender. It is the fixed launcher used for imitation infrared air-to-air combat bombs.
Following the order from Mr. Song, the person in charge of the engine behind the bunker, a fire lit up, smoke rose, and the sound of "rumbling" continued for a while.
As soon as the engine stopped working, a staff member laughed and said: "I don’t know anything else, but this smoke is much smaller than our original one, hahaha."
The comrade next to him glanced at him: "That means that the material ejected is not enough, and the thrust and impact are worrying."
The comrade became anxious: "What do you mean, the material ejected is based on this thing." Forget it?" Several people laughed and seemed to be in a good mood.
Mr. Song said: "Stop laughing, hurry up and look at the data and print it out."
The data is basically in the computer center next to it. The Institute of Guidance and Research is very close to the Keeping pace with the times, most of the sensors are connected to a DJS-59.
The program was compiled by themselves and has only one main function. It automatically collects and stores various data during the test and prints it out when needed. The maximum acquisition frequency can reach 500Hz, which is as high as heaven and earth for previous data recording methods.
You must know that the working time of the air-to-air missile engine may only be a few seconds. If you manually collect observation data, just rub your eyes and it will be done. Just remember some peak points and other nodes. If you want to draw a curve, it is a bit difficult. It’s a fantasy.
Of course, when there were no computers available for data collection, the Guangdong Research Institute also thought of many ways and researched a lot of equipment to ensure the frequency and accuracy of data measurement.
The effect is not that it cannot be used, but compared with a computer that automatically collects and records automatically, it is obviously inferior by more than one level.
They are not lacking in transmission, but they are lacking in high-speed collection methods.
Looking at 500Hz in the future, this collection frequency has nothing to do with high-speed collection, but at this time it is really high-speed collection.
What the Institute is thinking about now is to get a DJS-60D specifically for this task. After all, it is much more convenient than the DJS-59. For example, it can be installed directly in the test site. I hope this will happen soon. It's about to happen.
The 12th Machinery Department is recycling existing DJS-59s. If one is recycled, at least two DJS-60Ds will be distributed. For the Research Institute, this business can be done.
Several comrades immediately went to the computer room. After a faint "sizzling" sound of printing, they ran back with the data, looking happy.
Mr. Song took the data in their hands and scanned it.
"Working time, X.Xs"
"Average thrust, XXkN"
"Gas pressure, >
“.”
Calculating it in his mind using a formula he was already familiar with, Mr. Song was overjoyed: "Okay, according to this data, we can hit at least 13~15km!"
How far this can hit refers to the situation without considering the hit. Down.
Although this distance is slightly closer than the 17km of Sidewinder, it is not much better than the original Thunderbolt-2.
This data is also very normal. The charge structure was originally a copy of the Rattlesnake he picked up. This time Gao Zhendong even got them the original STD propellant of the Rattlesnake. It would be weird if they didn't get close.
But the people at the Guangdong Research Institute didn’t know that this propellant was the original propellant for Rattlesnake Fixed Hair. Before the test started, no one, no matter how courageous, dared to imagine that such data could be obtained.
The comrades jumped for joy.
“So far? I can’t imagine it.”
“Who would have thought, this thing is like a chicken blood.”
“Who said the thrust just now? I'm worried, huh?"
"It's me, come on, I'll give you my face, you don't have to hold back, haha"
"."
At this time, there was an exclamation from the comrade who was checking the engine's working status: "It's not good, the throat lining is broken!"
When everyone heard this, their heads went up. As if a basin of cold water had been poured on him, he quickly gathered around.
Excessive ablation is not a big problem. Just make it thicker. Now the thrust and thrust are sufficient, so I feel confident!
But if it is broken, that is another matter.
The throat lining of the engine still uses the copper-infiltrated and silicon-infiltrated graphite that Gao Zhendong helped the Northeast Carbon Research Institute develop in the first place. The faults are all known. If the working environment is harsh, the strength will decrease.
(End of this chapter)