Chapter 1031 Laser Selective Melting Forming
“Concentrate your efforts to conquer the material itself first?”
After hearing Chang Haonan’s ideas, Lu Qingsong’s first reaction was disbelief:
< br>"This is indeed more reasonable from a research perspective, but Mr. Chang, is it a little too late in terms of time..."
Processing on the basis of the materials already obtained, and starting from scratch...starting from the halfway point Compared with developing a new material, the workload is still much smaller.
Including the reverse engineering of 4722 alloy according to the original plan, it is also a relatively long-term task.
Sudden adjustments to the plan now will have a considerable impact on the entire project.
But now, Chang Haonan really has no choice.
“No way.”
He replied slightly helplessly:
"It is true that we are pressed for time, but since the attempt to use other titanium alloy substrates for testing and then push out the results has been proven to be unworkable, if we want to obtain the process parameters in a short time, we can only directly obtain enough 4722 alloy, establish a separate database and fitting formula for this series of materials, such results will definitely be accurate. "
"The easiest way to obtain enough 4722 alloy now is definitely. According to the contract, I asked Luoluo for it, but I didn’t want to return all the processed waste to them. That way too much would leak out... So I had to make two preparations.”
“One. We have concentrated most of our efforts on researching the 4722 alloy material itself. Although we may not be able to make blades exactly like Rolls-Royce in a short time, it is best to come up with base materials that meet the requirements, so that our computational modeling process can be It can be completed with your own materials, and there is no risk of leakage..."
"Of course, on the other hand, the turbine processing task of the Trent 900 itself is definitely still the most important, so you can't bet all your money on it. In this regard, if the alloy forming process has not improved by the end of this year, then the only choice is to ask the British for a second batch of follow-up samples..."
Hearing this explanation, Lu Qingsong looked solemnly. nodded.
The principle of technical blockade is the same.
The main purpose is to increase the cost and time for others to catch up.
As long as the latecomers’ technological iterations are not as fast as mine, the entire market will still be in a monopoly state.
So, if possible, everyone wants to extend this process as long as possible.
After a slight hesitation, he continued:
"Then if Xiro Company wants to know the progress...you know, it is Party A over there after all, and we can't not disclose even a little bit of information..."
And Chang Haonan's answer was almost without thinking:< br>
"It is said that the process parameters are being adjusted... In addition, the several sets of scrap products processed in this round of testing can also be dismantled and handed over to them in several batches. It should be enough for two or three months... "
"..."
Just when the two of them were ready to deal with the worst case scenario.
A figure appeared at the door of the office at the right time...
It was Hang Zhibin.
"Mr. Chang, and Mr. Lu."
He held a folder in his hand that was almost the same as the one in front of Chang Haonan, and walked in slowly:
"We trial-produced a batch of Ti-47Al-2Cr-2Nb based on the process we deduced from the data."
This sentence really shocked Chang Haonan and Lu Qingsong, who were discussing this matter just now.
Especially the former.
Almost jumped out of the chair:
"Trial production is out? Bar or profile?"
You can't blame Chang Haonan for being surprised.
Mainly because less than 20 days have passed since the start of the research.
In such a short period of time, even developing a complete process based on existing experience is a bit difficult.
Not to mention the output material itself.
Even with the help of the system, it would not have been possible so quickly...
Looking at the shocked two people, Hang Zhibin also showed a confused expression for a moment.
Then I realized that the other person would be mistaken.
Hurry and shook his head:
“How can there be profiles and rods... We just used the gas atomization process we developed in the past to make a batch of metal powder... "
Hearing his explanation, Chang Haonan breathed a sigh of relief. While he was glad that the scientific principles still existed, he was also a little regretful.
Of course, even for powder, 20 days is a very good progress.
Therefore, he certainly couldn't express his regrets:
"It doesn't matter. I have read the information provided by Rolls-Royce. The blade blanks are produced using laser selective melting molding technology." "Yes. Metal powder at least provides the basis for further research on the molding process... In addition, Gong Lu and I are also considering adjusting the R&D plan and focusing our efforts on base material production technology with you."
< br>
This laser selective melting molding process is a type of 3D printing.
It’s not really a new technology. It has been used in a small amount since the late 1990s.
However, at the beginning of the 21st century, it was not possible to directly produce finished products from powder as was done later.
A rough blank is almost produced first, and then subsequent precision processing is carried out using traditional processing methods.
Although Hang Zhibin still doesn’t know what happened specifically, for him, it will definitely not be a bad thing to have such two big guys joining.
So he nodded happily.
Then, he reported another progress quite excitedly:
"Actually, after the powder was produced, we also conducted two rounds of powder spreading and molding tests...but the results were not very good, so they were not included in this report."
"But since Mr. Chang, you are going to take charge of this personally..."
Hearing this, Chang Haonan's eyes lit up again.
Not even waiting for the other party to finish speaking, he hurriedly said:
“Tell me more specifically!”
"Well...it's trial production, so we all make 10mm cubic specimens, but only the upper and lower surfaces of the specimens are relatively flat. Obvious warping, burrs and unfused defects can be observed on the side walls, especially the side edges. And then from these defects..."
Since he did not bring the sample test report, Hang Zhibin could only organize the words while describing it, so it was inevitable that he was a little stuck.
However, what he said was quite familiar to Chang Haonan.
So much so that he interrupted the other party midway:
“You want to say that with these side edge defects as the source points, many macroscopic cracks have been produced, which can be clearly observed by the naked eye. The kind that arrived?”
Hang Zhibin nodded immediately:
"Yes..."
Then he immediately realized something:
"Wait... Mr. Chang, how did you know?"
< br>"Alas..."
Chang Haonan sighed:
“Because I encountered almost the same problem here.”
As he said that, he handed the test report that Lu Qingsong just brought to Hang Zhibin on the table. :
"Take a look, there is a picture on it, does it relate to you..."
Chang Haonan's voice stopped abruptly halfway.
Because at this moment, an idea flashed through his mind quickly, sparking a series of inspirations.
Laser selective melting molding properly utilizes the thermal effect of laser.
The ultra-short laser processing on his side is to reduce the thermal effect as much as possible.
But now the same problem has occurred on both sides...
As we all know, the direct cause of cracks is basically because the residual stress is greater than the tensile strength of the material itself.
However, current picosecond-level lasers are actually not enough to avoid all thermal effects.
In order to solve this problem, when Chang Haonan originally developed ultra-short laser processing equipment, he immersed the workpiece to be processed in liquid.
If you have to say where the two processes of molding and processing are similar, then it is probably only this process.
Not that the cooling method is the same -
Of course it is impossible to fill liquid during the powder molding process.
However, the higher temperature difference makes its heat transfer efficiency close to that of liquid cooling.
That is, the cooling rate is close to
In other words, the stress itself is likely to be generated during the cooling process of the material.
Furthermore, the boundary between the unmelted powder and the molten powder will form a gap, which increases the surface freedom. Therefore, cracks are more likely to occur on the side of the sample. In contrast, since the upper surface is composed of the last molten pool, the surface quality is better and is less likely to become a source of cracks.
This can explain why the upper surface of Hang Zhibin’s cubic sample is relatively smooth, while the side edges are in the worst condition.
"Researcher Hang..."
After a long time, Chang Haonan slowly said:
"I seem...to have thought of a solution."
(End of this chapter)< br>