Genius is just the threshold for me!

The following evening, a passageway leading to and from the core area of ​​the Chengdu Aircraft Industry Group (CAC) base.

After Lin Dong and Xu Qingling finished their meal, they submitted an internally distributed plastic food container and two sets of application materials for access control.

Xu Ziming's materials laboratory is located on the edge of the core area.

Although it's on the periphery, it's still considered part of the core area.

Ordinary employees and their family members of Chengdu Aircraft Industry Group (CAC) who want to enter must apply for temporary access permission, and then be led in by security personnel after their permission is confirmed.

"Xiao Dong, Qing Ling... are you delivering lunch to Minister Xu?"

The security personnel on duty today is a reconnaissance officer in his thirties who has retired from a certain military unit.

Having worked at Chengdu Aircraft Industry Group for nearly ten years, he obviously knew the two men. He took the testing equipment that had been placed aside from the food box, carefully reviewed the data again, and then explained to the two men.

"We all grew up here, so we know the procedures."

"External electronic devices are not allowed... um, this is also not allowed."

As the security guard spoke, he pointed to Wangcai, the mechanical dog following Xu Qingling, and said with a smile, "This is Chief Engineer Lin's new mechanical dog, right?"

I saw it running in tests last night. It has cameras and electronic instruments, but the recognition device hasn't been installed yet.

According to regulations, Chief Engineer Lin must come out to inspect the items. If he confirms there are no problems, then the items can be brought in; you cannot bring them in.

"clear."

Xu Qingling had often brought food or clothes to Xu Ziming before, so she was very familiar with these procedures and regulations. She turned to the mechanical dog and called out, "Wangcai, wait for us here."

"Woof woof!"

Wangcai barked twice and then lay down on the ground.

When it lay down, it cleverly found a spot on the grass nearby.

"Tsk tsk... If you put two submachine guns on this thing and create some tactics like you would with swarm drones, it would be invincible in battlefield assaults."

The security personnel, a retired military officer, was clearly an expert and immediately recognized the function of the mechanical dog.

"You didn't bring any external electronic devices, right?"

At this point, the lunchbox passed the inspection, and the security personnel took it out and returned it to Xu Qingling, confirming again, "We'll be going through the inspection gate later, and it will be very troublesome if they find any external electronic equipment."

"I didn't bring it."

Lin Dong and Xu Qingling nodded.

"Okay, don't wander around when you come in. Go straight to Minister Xu's place, and do the same when you come out."

The security personnel nodded, picked up the internal phone to contact Xu Ziming, and after receiving a confirmation, signaled Lin Dong and his companion to pass through the inspection gate next to them.

Then, seeing that Lin Dong and Xu Qingling passed through the detection gate without any abnormalities, he led the two of them without stopping at all, to the materials laboratory where Xu Ziming was now.

"Minister Xu is in the reception room outside. You can go straight in."

When they arrived at the laboratory door, the security personnel rang the doorbell to inform Xu Ziming, and then gestured for Lin Dong and the other man to go inside.

"Thank you, Uncle."

Lin Dong greeted Xu Qingling politely and went inside carrying the food box.

"Lingling".

As soon as they entered the lab, Xu Ziming came out as well. He took the food box from Xu Qingling and looked at Lin Dong, asking, "Why did you come along?"

"Uncle Lin and Aunt Xia are working overtime today, so Mom invited him over for dinner..."

Without Lin Dong needing to answer, Xu Qingling explained it for him.

In this regard.

Lin Dong nodded in agreement, indicating that this was the reason he was there.

"Aren't there public canteens in the outer areas?"

Xu Ziming replied, but didn't say anything more, and led the two inside.

After turning the corner of the corridor, a small reception room comes into view.

The setting sun streamed in through the window, and some documents were scattered on the table. Wang Xingguo was holding one of the documents, frowning as if he were thinking about something.

"Godfather".

"Uncle Wang."

Lin Dong and the other man called out.

"Xiao Dong, Qing Ling, they're here..."

Wang Xingguo looked up and saw the two of them. He put down the documents in his hand and rubbed his forehead.

"Godfather, what's wrong?"

Seeing Wang Xingguo's troubled expression, Lin Dong noticed some data about third-generation single-crystal nickel-based alloy materials on the documents on the table and asked curiously.

Last night, this guy was so excited he was about to jump for joy, and he was so confident that he would dare to bang on the table when he went to meetings at headquarters in the future. How come he looks so troubled and distressed today?

"The defect rate is too high..."

Wang Xingguo sighed, about to say something.

At this moment, Xu Ziming brought two chairs for Lin Dong and the other person and said, "What are you talking to him about? He's not a materials scientist, he's never been exposed to or studied this field, he wouldn't understand even if you said something."

"..."

Lin Dong fell silent, unsure how to respond.

Wang Xingguo, the one in charge, twitched at the corner of his mouth, but still said in a steady tone, "The more people listen, the more ideas we have."

I'll explain it simply. Xiao Dong is more quick-witted than you; he might come up with some ideas after listening.

"Yes, Dad, come and eat quickly, or the food will get cold and won't taste good."

Xu Qingling called out from the side, pulling Xu Ziming aside and opening his lunchbox to urge him to eat quickly.

"Only Qingling can cure you."

Wang Xingguo gave Xu Qingling a thumbs up, and then continued to Lin Dong: "The third-generation single-crystal nickel-based high-temperature alloy has achieved a breakthrough in mass production, but the current data and technology can only maintain a 28% pass rate. If we further increase the temperature of the melt overheating, we can barely break through the 50% pass rate."

"Isn't this quite tall?"

Lin Dong asked curiously.

Unlike ordinary metals that are melted and cooled to form shapes, or semi-melted and forged, they are different from the ordinary metals that people usually imagine.

Single-crystal materials are "grown" and "developed," and the environment for "growing" and "developing" them is extremely demanding.

Even slight impurities, temperature fluctuations, or environmental variations can cause material production failures.

With a melt overheating pass rate of 50%, mass production has been successfully completed and the conditions for mass production and promotion have been met.

The first-generation single-crystal nickel-based alloy dd3 initially had a pass rate of only 15%, but after melting and overheating, the pass rate was increased to 50% to 60%, which allowed for large-scale application and mass production.

As for melt overheating, this is a technique that reduces impurities and the rate of impurity crystals by increasing the temperature of the alloy solution.

For example, if the melting point of an alloy is 1400°C, then further raising the temperature to 1600°C or 1750°C and stabilizing it for a period of time will burn off the impurities inside, while increasing the fluidity of the solution and reducing the impurity crystal rate.

Of course, the problem of melt overheating is not without limits.

If the temperature is too high or the time is too long, the crucible containing the solution will detach or even dissolve due to the high temperature, resulting in a large number of new impurities.

As for the final temperature and time to be maintained, that depends on a large amount of experimental data and experience.

"This is the pass rate of DD33, not the pass rate of DD9 single crystal materials used in the engine manufacturing project of Emei."

Wang Xingguo sighed: "As for the pass rate of DD9, it's less than one in a thousand."

"Not even one in a thousand..."

Lin Dong paused for a moment, then couldn't help but shake his head.

Even if the pass rate is 1 percentage point, it's still possible to maintain a pass rate of 0.5 percentage points.

Given the strategic importance of the Emei WS-15 turbofan engine, the domestic government is willing to use a "splurging" approach, incurring excessive costs to produce a batch in order to bolster national defense strategy.

But even one in a thousand is less, which means it's impossible to mass-produce them.

The reality is not that it has a pass rate of a few tenths of a thousand, but rather that the testers stopped testing at this point and did not continue testing.

The actual pass rate may be one in ten thousand, one in one hundred thousand, or even zero.

"Has Uncle Xu found the problem inside?"

Lin Dong looked at Xu Ziming, who was eating rice.

He hasn't looked at the specific data yet, so he can't just make predictions based on imagination.

Although the mass production of dd33 has been successful, this is something to celebrate for the domestic materials industry and the high-end materials market.

However, the failure to mass-produce the DD9 meant that their hopes were dashed.

Although both DD33 and DD9 are third-generation single-crystal nickel-based high-temperature alloys, their strength and toughness are quite similar.

However, DD33 has poor weather resistance and is only suitable for use in some ordinary extreme environments.

If used to manufacture turbine blades for the WS-15 engine, it would have to withstand the extreme high temperatures and pressures inside the engine, as well as the harsh environment of high-speed centrifugal torque. DD33 would turn into metal noodles in just a few hours inside.

"Temperature fluctuations."

Although Xu Ziming didn't think Lin Dong understood materials science, he didn't hide it from Lin Dong, as it was rare to hear Lin Dong ask him questions.

"I carefully compared the timeline of the experimental data and divided the data into different time segments, each in 30-second increments."

Ultimately, it was discovered that a slight fluctuation in crystal temperature occurred during the period when impurities and stray crystals appeared.

If we only need to produce nano-thin sheets, then DD9 can actually be considered a successful mass production.

Because this temperature fluctuation doesn't occur all the time, it has a stable range. We just need to select materials that grow stably within this range.

Unfortunately, what we need are the macroscopic blades.

The material required for a single leaf is so thick that it takes at least several hours to grow, which means we only get a piece of material with mottled impurities and crystals inside...

Done.

After finishing the last bite of his meal, Xu Ziming put down his chopsticks and said in silence, "I talked to the lab today about whether we could improve the temperature control precision, but the answers I received were not ideal."

For single-crystal materials, all the metal atoms must grow in the direction you envision to ultimately obtain a macroscopic material.

The entire growth process cannot produce deflection or stratification; this already represents entering the quantum scale and beginning to challenge the limits of the atom.

Although the crystal bonds between metal atoms have their own adsorption forces, these adsorption forces only act at the microscopic level and are too weak.

Even the slightest macroscopic fluctuation during the growth process is no less than a tsunami or storm for these growing metal atomic crystals…