Chapter 588 Perfect Single Crystal

"Nine and a half percent..."

Ma Liping opened his mouth several times, but in the end no sound came out.

Mainly because I didn’t know what to say for a while.

He had no choice but to turn his attention back to the operators who were busy up and down around the directional solidification furnace.

As a researcher, he naturally understands the "hidden rules" in the discourse of some colleagues.

Being able to tell the figure of 95% is basically equivalent to having 100% confidence.

It's just that out of respect for statistics and of course metaphysics, I won't make my words so absolute.

To be honest, Ma Liping is actually a little nervous in his heart.

He has been studying the field of casting technology for more than ten years. Although China's domestic level in this area is not high, he has been tracking the cutting-edge progress abroad.

Even the countries that are currently doing the best in “precision” process optimization can still only achieve directional rather than quantitative results.

The final parameter determination still requires trial and error and debugging during the trial production process.

It's just that it's much more efficient than the experience-trial-and-error approach, which is almost purely based on ignorance.

This is still based on improvements based on existing technology.

The crystal selection method and liquid metal cooling process in front of us is completely new to China...

Can you really penetrate the soul with just one shot?

I'm afraid it's not very scientific...

Of course, thinking about it, Ma Liping is not a newbie who has just entered the workplace, so he will definitely not say such things.

Just kidding, the other person became the chief engineer of a national key model in his twenties. His ability and background are probably extraordinary. How can he, who was only appointed as a professor in his fifties, be so successful...

Even if you really don't succeed in the first attempt, the most you can do is complain in your heart.

Therefore, after a moment of silence, he responded again:

"If we can succeed once, it would be the best..."

While talking, the operator had already completed the setting of the process parameters and conducted the final inspection in accordance with Chang Haonan's requirements.

"Mr. Chang, Director Ma, the first trial production of DD8 single crystal alloy blades is ready and can start at any time."

The section leader who personally led the team trotted over and reported to the two of them.

Ma Liping did not answer directly, but looked at Chang Haonan beside him.

Although he, the director of the foundry center, had no administrative connection with the latter, there was obviously no doubt about who was involved in the current scene.

However, Chang Haonan was not prepared to overstep this authority.

In the Turbofan 10 project, he no longer lacks a sense of presence.

There is no need to steal this limelight.

Moreover, Chang Haonan also heard a somewhat concerned tone from the other party's long-awaited answer just now.

"Director Ma, are you the direct leader regarding the casting center matters, or should you give orders."

At this moment, Ma Liping was still a little surprised.

In fact, he did not doubt that Chang Haonan would eventually be able to produce this single crystal blade.

Therefore, this first trial production, the first of its kind in China, will definitely remain in the history of the aviation industry.

But now, this opportunity fell directly on his head.

"Agree to start trial production!"

Although Ma Liping had taken two deep breaths in advance, when he said this sentence, there was still a slight vibrato and broken sound.

And the doubt in his heart just now, which he might not even notice himself, and the idea of ​​waiting to see a joke, also disappeared without a trace with this gaffe that had nothing to do with the overall situation...

With his order, the vacuum pump started working first, followed by the cooling water pump, heater, stirrer, linear motor...

A monotonous and harsh roar sounded in the workshop, but no one found the sound unbearable and still stopped where they were.

Everyone wants to see the results of this trial production as soon as possible.

In the end, Chang Haonan felt that after actually entering production, it seemed useless for his group of people to stand here. On the contrary, it would distract the operators next to them, so he suggested loudly:

"Let's go to the lounge first and come back when the results are about to come out."

His voice reached everyone's ears above the rumbling sound of the compressor.

Ma Liping turned his head to look at Chang Haonan with a surprised look on his face.

Although logically speaking, he also knew that researchers like himself would not play any role in actual production.

But few people can maintain a truly stable mentality when their major scientific research results are implemented.

They all wish they could watch the whole process with their own eyes.

Looking at it this way, the other party is indeed... quite relieved about this process.

Ma Liping had been teaching at Liao Provincial University in the non-military industry system in the past. He had just joined Liming Group not long ago, and this was the first time he had direct dealings with Chang Haonan.

Although it has not yet been determined whether the trial production can really be a success in the first time, the latter's calm and composed attitude during this important matter also made him admire him in his heart.

…

Although the process improved by Chang Haonan can "efficiently" produce turbine blades, that is compared to the past.

The directional solidification method sounds fancy, but in essence it is still precision casting.

As long as it is precision casting, it is a matter of slow work and careful work.

For example, the blade pulling speed during the solidification process is measured in millimeters per minute.

This process alone will take an hour or more.

Therefore, by the time the entire production process was completed, it was already this afternoon.

Chang Haonan and his team returned to the production workshop in advance and witnessed the entire process of the completed turbine blades being taken out of the directional solidification furnace, cleaned, and cooled.

Finally, after waiting for about half an hour, a set of products was finally handed over to everyone by the section chief——

Generally speaking, in order to ensure efficiency, turbine blades are not manufactured one at a time, but in groups, usually 4-6.

Even for trial production.

Because there are many destructive items in the subsequent testing, more samples need to be prepared.

On the surface, these leaves look a bit unattractive, even gray, and do not look like the high-precision products that most people imagine.

But for the insiders present, it can be seen that these products at least do not have defects such as shrinkage holes, freckles, and striped crystals that can be seen with the naked eye.

Compared with the previous useless models that could be directly included in the textbooks, they are already so good that I don’t know where they are.

Of course, the more detailed parts at the crystal level require further testing with equipment.

"Quickly, send it to the testing center for comprehensive testing, especially the alloy morphology and elemental composition. The results will be available as soon as possible."

Ma Liping turned around and handed the sample to an assistant behind him.

Originally, Liming Factory usually sent this type of testing outside for testing, just like what Chang Haonan did two years ago.

But after the precision casting center was established, they spent huge sums of money to purchase a batch of equipment, which greatly reduced the time waiting for test results.

Soon, several X-ray detection and electron microscopy test results were sent back after being copied.

Ma Liping almost grabbed the report, pointed it at the light not far away, took off his glasses and moved closer to examine it carefully.

"Cross-section dendritic structure, cross-petal morphology..."

"The primary dendrites grow in the vertical direction with a spacing of 373 μm, and the secondary dendrite arms are distributed in parallel with a spacing of 80 μm..."

"The average size of dendrites is 450 nm, and the average size of dendrites is 670 nm..."

As the report went further and further, his expression changed from nervous to relaxed, and finally to ecstatic.

However, just when he turned to the last page of the test report and was about to open the champagne, the expression on his face suddenly froze.

"The longitudinal segregation coefficient of aluminum element is 0.82, the longitudinal segregation coefficient of cobalt element is 2.60, the rhenium element is 12.28, the tungsten element is 32.21..."

"The γ/γ' eutectic phase content is 13.6%..."

Ma Liping raised his head with a confused expression and looked at Chang Haonan beside him:

"Mr. Chang, is this...the content of the eutectic phase a little too high..."

"And...Although the overall content of impurity elements is very small, the distribution is uneven. The rhenium and tungsten elements that affect performance are almost all concentrated at the root of the blade, which is very detrimental to the working stability..."

In fact, when he first heard Chang Haonan say that he could succeed in one attempt, Ma Liping even wanted to see the other party suffer.

But now, when he actually saw the result, he felt completely unacceptable.

The previous test data were all very good, so why did something go wrong at the end?

I prayed ninety-nine times, but I trembled and didn't understand the last one. This is the most annoying thing.

However, Chang Haonan, who was not far away, showed no signs of anxiety at all. He was writing and calculating with his head down and holding another piece of information...

"Mr. Chang?"

"Director Ma, you are too anxious..."

After a while, Chang Haonan raised his head again and handed Ma Liping the information he had never taken out before:

"We are in trial production, and we need to conduct a test after each process."

"There is still a heat treatment that has not yet been completed. The blades are still only semi-finished products. Naturally, they cannot be perfect in every aspect."

After being told this, Ma Liping realized how embarrassed he was.

It's not that I didn't understand when I shivered at the last moment, it's that I haven't started shivering yet...

Of course he didn't know that there might be subsequent processing techniques after the blades were formed, but he might have been too nervous just now and his mind was in confusion.

Compared to Chang Haonan, who is in charge of process design, he seems to be more caring and chaotic...

Thinking of this, Ma Liping forced himself to calm down, and then looked down at the information Chang Haonan had just given.

This is a dense form that spans several pages.

He quickly saw that this was a parameter table for the heat treatment process.

Each process corresponds to different defects in semi-finished products.

In other words, Chang Haonan had predicted the possible test results in advance and made different heat treatment plans accordingly.

Now you just need to select according to the table!

At this moment, Ma Liping suddenly felt...

So be it.

He had always been curious about how Chang Haonan planned to deal with product differences caused by equipment and environmental fluctuations during the crystal casting process.

As a result, they calculated everything directly...

At the same time, Chang Haonan has handed over the selected heat treatment parameters to the section chief who has been waiting beside him:

"You should have seen the process of choosing a craft just now. Just follow my method from now on. Go deal with it!"

The subsequent waiting process seemed a bit boring compared to the previous one.

Chang Haonan's preparations have reached this outrageous level. Even if everyone was a little worried about the final result of the trial production just now, they have basically stabilized their mentality now.

Unsurprisingly, when the final sample test results after heat treatment were sent again, the element segregation and eutectic structure had been greatly alleviated, and the content of the γ′ phase was almost one-third higher than before.

In other words, it is almost a perfect single crystal of DD8 material!

"Turbine blades, is this considered...made?"

He Ming, who had not spoken much just now, felt that the world seemed a bit unrealistic.

Chang Haonan did not answer his question. He just put the blade back into the box and turned around:

"Okay, now that this problem has been overcome, the production of the combustion chamber and turbine subsystems should also be put on the agenda!"