Chapter 1032 A clever plan to calm the world...


    ??If the cause is really a cooling rate problem, then for Chang Haonan''s processing tasks, he only needs to increase the liquid preheating temperature and lower the cooling rate.


    ?Of course, this is just a principle level.


    In the specific implementation, considering that the thermal conductivity of the originally used neutral salt solution is not small, and if the preheating temperature is high, there will be evaporation or even boiling problems, there are still some areas that need to be overcome.


    Applying another set of pressurizing equipment for this purpose will further increase the complexity of the system.


    But if I change the type of liquid, I can’t seem to think of one that particularly meets the requirements.


    As for material forming, it is more complicated.


    For traditional metallurgical processes, a special stress relief annealing process can be set up.


    But laser selective melting, as a powder molding process, is actually cooled while processing.


    In other words, even for a 10mm cubic specimen, the cracks that should be formed have already formed before the entire molding process is completed.


    So, it is definitely too late to anneal afterwards.


    Only real-time post-processing can be considered.


    That is to say, annealing while processing.


    Fortunately, annealing is essentially a process of slow heating and then slow cooling.


    Theoretically, another annealing laser can be set up to follow the processing laser to complete this operation.


    If we want to think of other solutions, it is a matter of metallography.


    According to the previous material characterization and the calculation results of Chang Haonan, the eutectoid reaction α→γ+β is very sensitive to the cooling rate. Therefore, more α2 phases with a close-packed hexagonal lattice structure will be formed inside the matrix, and this structure will slip. There is less α2 phase and it is a typical brittle phase. Therefore, the tensile strength of the area containing more α2 phase is lower. When the residual stress is large, it is more likely to become the initiation and expansion area of ??cracks.


    In other words, reducing the proportion of α2 brittle phase can inhibit the occurrence of cracks.


    ?However, the process of melting and molding itself will affect the phase composition of the final product, so it will not be much simpler than the idea of ??annealing while processing...


    In short, there is no way to solve the problem by just doing it.


    But at least, the research direction can be determined.


    ?After sorting out his thoughts in his mind, Chang Haonan quickly tidied up the table, and then briefly described his thoughts to the other two.


    Then there was a long silence...


    In the end, it was Lu Qingsong who spoke first:


    "Although there is no evidence...but at least the speculation is reasonable."


    ?Hang Zhibin also said immediately:


    "We can specially produce a batch of samples with molding progress ranging from 20% to 90%, and then use them for scanning electron microscopy inspection and X-ray diffraction analysis, so that we can quickly judge the two intermediate speculations of Mr. Chang. That is to say, cracks are generated at the same time during the molding process, and the content of the α2 brittle phase will affect whether the difficulty of crack generation is correct. "


    “If these two contents are correct, then although it is not particularly rigorous, it can be basically considered that the crack generation mechanism mentioned by Mr. Chang before is no problem.”


    There is no problem with the mechanism, then there will be no problem with the subsequent solution.


    Therefore, the three people quickly reached an agreement on the matter.


    “The next step…”


    Just when Chang Haonan was about to formally arrange the follow-up work, Hang Zhibin suddenly changed the topic:


    “Wait, there’s something else…”


    ?Chang Haonan and Lu Qingsong turned to him at the same time.


    “This process requires multiple comparisons with the samples provided by the British side, and we originally had to conduct comparative tests on the machining properties of the materials later…”


    ?Hang Zhibin explained:


    "So, we need more samples, I mean... the semi-finished products samples provided by the British side."


    ?Hearing this request, Lu Qingsong was a little hesitant.


    “But now the quantity is not enough…”


    However, Chang Haonan agreed readily: "It doesn''t matter, just ask Luo Luo for the second batch of samples."


    "ah?"


    ?Lu Qingsong looked at Chang Haonan with a confused expression.


    The latter replied nonchalantly:


    “The contract does not stipulate the specific use of these samples, it just requires us to return them after testing.”


    “We don’t want to use it because we are worried about leaking secrets, but researcher Hang’s test is to reverse engineer them, and there are no secrets to leak...”


    ??The confusion on Lu Qingsong’s face suddenly turned into realization—


    Still imprisoned by the fixed mindset...


    …


    Soon, Rolls-Royce received a request for a second batch of processing samples.


    ?Furthermore, according to the contract, the first batch of consumed samples was also returned to Ciro Company at the same time.


    The latter brought it to the UK as a human express delivery as quickly as possible—


    The low-pressure turbine assembly is smaller and the number of samples itself is also limited, so there is no need to bring a cargo box like last time.


    The person responsible for this human flesh delivery was Adam Whittle, one of the two British representatives of Ciro Company.


    As soon as he got off the plane, he was taken directly to the Rolls-Royce headquarters in Derbyshire.


    ?Including Lapworth, Bodie, and the head of the process team, Nate McGill, almost one-third of the supervisory leaders of the Trent 900 project team are already waiting here.


    ?This attitude directly surprised and delighted Whittle, who had been away from Luo Luo''s inner circle for many years.


    “Is this the waste product produced by the Chinese people during process testing?”


    Lapworth carefully pulled out a leaf parison from the sample bag, frowned, and asked.


    ??Though she was speaking to Whittle, the latter was clearly not high on the priority list for answering the question.


    McGill, who was sitting next to him, leaned over to take a look, and then gave a direct answer in the affirmative:


    “That’s right, we put special markings on the blade root and blade tip before shipping. This has obviously not been dropped.”


    "no…"


    Lapworth raised his forehead helplessly:


    “I mean…the nickel-based alloy blades they came out with last time were perfect, but what about this one…”


    ??As she spoke, she turned the direction of the blade and showed it to several other people around her.


    ?Then, there was a sound of inhaling in the conference room—


    The entire upper surface is almost covered with fine cracks visible to the naked eye.


    Even without any testing equipment, you will know that it is absolutely a waste product.


    It is almost the same as the samples in the previous trial production process.


    “If you ask me, this is normal.”


    ?McGill is responsible for process research and development and has a fairly clear understanding of the difficulty of this process:


    “The processing characteristics of titanium alloys and nickel alloys are inherently different. They obviously have no experience in this area in the past, so they can only explore from scratch..."


    Having said this, he took the leaf in his hand, looked at it for a while and then showed a smile:


    “And, only in this way can we fully understand the research and development process of the Chinese people, and thus deduce the specific process routes they use, and even... process parameters.”


    Bodi, who had been silent just now, frowned:


    “Don’t rely too much on these, McGill.”


    “You know, the results obtained by such backward deduction may not be completely correct sometimes... and may even interfere with the normal research and development process.”


    In fact, he was not very supportive of reverse engineering at the beginning, but McGill convinced the director of the Trent 900 project, who was also the direct superior of all of them, to turn his suggestion into a decision.


    After hearing this, the latter returned the leaf in his hand to Lapworth, wiped the unknown liquid on his hand and said:


    "So...I divided my staff into two groups. One group is responsible for cooperating with Oxford Optical Instruments and continuing forward development, and the other group is working with me to try to see if they can find anything useful from the Chinese test samples. thing."


    "Judging from the current situation, the Chinese people...are not aware of our methods..."


    (End of this chapter)