The Military-industrial Scientific Research System of the Academic Master Chapter 971

Chapter 971 I guessed it right, but not completely.

In fact, while the British felt threatened, Snecma on the other side of the English Channel was not as joyful as the former imagined -

For Dassault and Aerodynamics Group, as soon as Vesta signs off, the M88-3 engine turbine component testing can be considered over, and the next step is to enter the next phase of work step by step.

However, for Snecma himself, it was far from the case.

Don't forget, in order not to delay the critical time node, the samples used in this round of testing were all directly provided by China.

So now the most we can confirm is that "there are no problems with the turbine components designed and produced by China."

But what do the French make themselves...

Don't know yet.

Therefore, after sending the test report to the two upstream and downstream partners, Vesta almost had no time to rest and immediately turned its attention to the trial production workshop.

The materials, coatings and production processes used in the M88-3 turbine itself have not changed at all compared to the M88-2, with only slight differences in the outer contour parameters.

But it is not difficult for established industrial countries to solve.

In fact, from beginning to end, the semi-finished blanks used by China were provided by Snecma.

Therefore, the only technical difficulty that needs to be overcome is the final manufacturing of the air film holes.

Since the end of November last year, when Vesta brought relevant technical data back to France, Snecma's production department has begun to verify the process parameters of drilling processing in accordance with the production requirements provided by China.

However, it encountered huge resistance at the beginning, resulting in almost zero progress in the first few weeks.

Not to mention good products, not even complete scraps were produced.

Later, as the samples provided by the Chinese arrived, Vesta focused on the most urgent testing tasks.

Only now that all other work has come to an end can we start to focus on production-level issues again.

"Doctor, these are the blade samples we made using different processing methods and processing techniques in the past month."

Gene Duflo, the person in charge of trial production, led Vesta to a workbench, pointed at the dozens of turbine blade samples densely spread out on the table and introduced:

“We have checked the design documents and found that although the specific hole shapes involved in different parts are different, the basic characteristics and properties are the same, so in order to speed up efficiency, we all used blades with smaller area and thickness for trial production. "

Vesta didn't reply immediately, but just nodded, which was considered to be recognition of the other party's choice.

As long as the holes in the blades are clear, the combustion chamber and the turbine disk are basically the same.

"Is this all?"

After looking down for a while, he raised his head again and asked Duflo.

"That's not true."

The latter shook his head:

"There are also some samples that couldn't even be successfully punched, so they're not here."

"In general, if production efficiency is not considered, we can produce products that meet the requirements. Of course, at present, we can only say that they meet the requirements in terms of specifications. After all, they have not been systematically tested."

While talking, Duflo took out one of the leaves from a pile of leaves and handed it to Vesta.

It was of course impossible to tell with the naked eye whether the inner wall of the air film hole met the requirements, so Vesta did not do anything extra and just took a rough look at the outer surface.

He noticed that at the base of the blade, there was the word "EHB-29" written on it.

“EHB…”

The movement of Vesta's hand stagnated slightly:

"You changed the process?"

In the past, Snecma's common process for processing air film holes was tube electrode electrolytic machining, and the sample abbreviation was generally TEE-xx.

And more importantly, he could not see the annular etching marks left after the tube electrode processing around the air film hole -

This trace only remains on the surface of the thermal insulation coating and will not affect the base material. The area around the air film hole is already a relatively low temperature location, and the requirements for thermal insulation are relatively low.

Therefore, unless there are special requirements, an additional coating will not be added after processing.

"That's right."

Duflo nodded helplessly:

"We have tested many times using tube electrode electrolysis, but the internal shape of their channel is too complex and the hole depth is relatively large. There is no way to avoid secondary corrosion caused by the gap surface on the opposite side of the electrode."

"Furthermore, during the electrolysis process, the sodium nitrate solution will precipitate insoluble salts. In the past, we processed fan-shaped through holes, and even if there were salt crystals precipitated, they could be easily removed. However, this is also because the internal structure of this hole is too complex, and there may be some problems during the processing. There is a probability of more than 90% that the processing channel will be blocked. If the blockage is not processed in time, it will cause discharge breakdown. Not only will the workpiece be scrapped, but even the electrodes may have to be replaced..."

"So later, we simply switched to the electro-hydraulic beam machining method. Because during the machining process, the electro-hydraulic flow will rush towards the workpiece at high speed, so no matter how complicated the inside of the hole is, there will be no clogging problem. This debugged about half of the parameters, we have obtained the first sample that fully meets the standards.”

He said and pointed to the EHB29 in Vesta's hand.

"You just said...if you don't consider production efficiency..."

Vesta looked at the blade in his hand and said slowly: "You mean the electro-hydraulic beam processing process is very cumbersome?"

"yes…"

Duflo sighed, then replied:

"Theoretically speaking, electro-hydraulic beam machining is good at processing tiny holes with special angles. The diameter of the air film holes is calculated in millimeters, which requires repeated hole expansion in multiple stages. There are many air film holes on each blade, so processing The time has increased exponentially.”

"The sample you have in hand, not counting the process preparation stage, the production alone took almost a day and a half... Calculating this, it will take us about 45 days to complete the processing of all the components required for an engine..."

After hearing this answer, Vesta couldn't help but curled her lips.

Although the demand for military engines is not high, building 9 units a year is too abstract.

Even if the proficiency issue is taken into account, the mass production speed will be doubled.

18 units a year is still not enough.

Not to mention that there will be civilian models derived from it later.

You know, when they first came to China, they originally just wanted someone to help solve the reliability problem of the M88-2.

As a result, later on, it became a slippery **** to help with performance upgrades throughout the life cycle.

Later, when it came to the SeA series of products, even half of the development leadership was taken away by the other party.

If mass production in the future depends on others to complete key processes...

"hiss…"

Vesta couldn't help but gasp.

He had never had time to think about it before.

The result is now that I think about it.

It seems...not completely unacceptable?

Thinking of this, Vesta quickly shook his head, trying to drive away the random thoughts in his mind. At the same time, he warned himself that this must be affected by the sausage-slicing tactics.

In order to divert attention, he quickly asked a new question:

"Have you studied the samples provided by China? Can you refer to their hole-making methods?"

In the past, Vesta would never have said such a thing.

But now, even he himself has begun to refer to Chinese technology to upgrade the M53-P2, so it doesn't matter.

"Of course, after hearing the test results came out a few days ago, we asked for a few brand new blades from there for backup."

As he spoke, Duflo turned to a computer and opened a Word document placed on the desktop.

Vista also moved closer to the screen.

"Judging from the conditions of the inner holes, we can indeed find some significant processing features, but when combined... it is difficult to determine what process it is."

Duflo said in a troubled tone while scrolling the scroll wheel to turn down the page:

"Through a high-performance microscope, the remelted layer can be vaguely distinguished from the inner wall of the air film hole. Although the thickness is very small and will not have any impact on performance, it is definitely a trace left by thermal processing. In addition, Huaxia's technology The staff has previously published an influential paper in Nature, and the content is indeed related to laser processing. "

"However, the entire blade has neither thermal stress nor micro-cracks, even if they only exist on the surface of the coating, and it does not look like a product of pure laser processing..."

"I have read the paper you mentioned."

Vesta suddenly interrupted:

"Not only China, but the British are actually also researching technologies related to using high-energy lasers to process turbine components, but as far as I know... the situation is not optimistic."

"Rolls-Royce's Trent900 engine is stuck in processing efficiency. It is said that the yield rate is too low, resulting in high costs. This is also the biggest advantage of its rival GP7200..."

In the field of civil aviation development, except for the core technical level, everyone is generally relatively open.

Therefore, although Snecma cannot participate in the competition of this type of ultrthrust-level aviation engine, it can still obtain relevant information in a timely manner as long as it is willing.

However, Duflo was only a mid-level technician and was not very interested in things that he could not participate in, so he continued the original topic:

"So... the direction we are currently considering is whether the Chinese will use composite processing technology, such as using electrolyte jets to assist laser processing. This can at least explain why they can control thermal stress and remelted layers."

"Of course, this is a relatively new technology for us, and we may need some additional funds to purchase new equipment and test consumables."

Tu Qiong dagger saw it belongs to yes.

It is naturally impossible to develop new technologies without money.

Of course Vista also understands this, but the group's funds are indeed somewhat tight right now.

"How feasible do you think it is?"

After hesitating for a moment, he finally spoke and confirmed.

"Even if the pure electro-hydraulic beam process can be successful, then the efficiency of the composite processing will not be lower at least."

Duflo's first sentence was very straightforward, but then he changed the subject:

"As for whether we can achieve the level of Chinese people...I can't make a conclusion yet..."

(End of chapter)

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