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 the contract, the testing of the turbine components of the M88-3 engine 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 did the French make themselves...


    Don’t know yet.


    ?So, 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 the old industrial countries to solve the problem.


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


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


    Since the end of November last year, when Vesta brought relevant technical data back to France, Snecma''s production department began to verify the process parameters of drilling according to the production requirements provided by China.


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


    Let alone good products, we didn’t even produce complete scraps.


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


    It is only now that all other work has come to an end that we have started 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 to 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 did not reply immediately, but just nodded, indicating that he recognized the other party''s choice.


    ?As long as the holes on the blades are clear, the holes on 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 the case.”


    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 we don’t consider production efficiency, we can produce products that meet the requirements. Of course, we can only say that they meet the requirements in terms of specifications. After all, they have not been systematically tested.”


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


    With the naked eye alone, it is of course impossible to tell whether the inner wall of the air film hole meets the requirements, so Vesta did not do any unnecessary things and just took a rough look at the outer surface.


    He noticed that at the root of the blade, the words "EHB-29" were written.


    “EHB…”


    ??The movements of Vesta''s hands were slightly stagnant:


    “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—


    ? Such traces only remain on the surface of the thermal insulation coating and will not affect the base material. The area around the air film holes 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 applied 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...”


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


    "yes…"


    ?Duflo sighed, and 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 including 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..."


    Hearing this answer, Vesta couldn''t help but curled his 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.


    Eighteen units a year is still not enough.


    Not to mention the civilian models that will be derived 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, it became a slippery **** to help with performance upgrades throughout the life cycle.


    Further on, 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 occurs in the future, we will have to rely on others to complete key processes...


    …


    ?Vesta couldn''t help but take a breath of air.


    He had never had time to think about it carefully 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 use 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 for backup.”


    ?While speaking, Duflo turned around and walked to a computer and opened a Word document placed on the desktop.


    ?Vesta 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 kind of process it is.”


    Duflo said in a troubled tone as he scrolled 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 those that only exist on the surface of the coating, and it does not look like the product of pure laser processing..."


    “I have read the paper you mentioned.”


    ?Vesta suddenly interrupted:


    “Not only China, but also the British are actually studying related technologies of using high-energy laser 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.


    ?Hence, although Snecma cannot participate in the competition for this ultra-large thrust level aircraft, you can still get relevant news in a timely manner if you are willing.


    ?However, Duflo is only a mid-level technician and is not very interested in things that he cannot participate in, so he continues the original topic:


    “So...the direction we are currently considering is whether the Chinese use composite processing technology, such as electrolyte jet-assisted laser processing, which 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 sees it and it belongs to it.


    It is naturally impossible to develop new technologies without money.


    ??Vista certainly 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, 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 this chapter)