Chapter 847 Carbon Fiber Reinforced Resin Matrix Composite Materials
In order to avoid the limelight, and of course to follow up on the M88 engine cooperation project, Chang Haonan stayed in Shengjing for nearly a month and did not return to the capital until early July. .
At this time, the popularity of proving the Poincaré conjecture has gone down a lot——
Firstly, it is because theoretical mathematics is relatively far away from life after all. As time goes by, people naturally do not know how to do it. I keep paying attention to a topic that I don’t understand.
Secondly, the two authors of the paper disappeared at the same time after the mathematical community determined that the proof process was valid.
Chang Haonan did appear once in a CCTV interview, and Perelman directly found out about this person.
As a result, the smooth combo of "lecturing - awarding - adding titles" that was supposed to be played got stuck in the first step.
Even if some media want to follow up the report, they can’t find a focus.
Of course, in the final analysis, although the proof of the Poincaré conjecture is very long, it is not difficult to understand.
Even if there is no personal teaching by the certifier, many people can still understand it.
Unless you want to integrate the theoretical tools in the paper, it will be more difficult.
So objectively speaking, there is no particularly strong motivation in the academic world, so these two people must be picked out.
As a mathematician, having a weird temper would be more in line with people’s stereotypes.
If it were really normal, the filter would be shattered all over the place.
In short, when Chang Haonan returned to the capital again, the commotion caused was relatively small...
"Professor Chang, I want to take a vacation..."
On the first day of Chang Haonan's return to work, Liu Chenchen put the work report of this period on the former's desk with a look of despair, and then asked road.
In fact, as a scientific research unit affiliated with the school, the Torch Laboratory, at least in theory, has one month each in winter and summer vacation.
But the boss had specially assigned a task before leaving, so it was impossible for her to give up and leave midway.
So I was bombarded with calls, emails and letters for more than half a month.
Finally got over it.
“Yes.”
Chang Haonan looked at the haggard Liu Chenchen and knew that he had been suffering recently, so he agreed very simply:
“ But before I go on vacation, I have to register the things on the list that Li Yabo gave you before.”
About three months ago, Li Yabo expressed his desire to study topics in the field of composite material microstructure, so he ordered it. A lot of equipment and experimental materials.
Now most of the things have arrived one after another, and many of them need to be registered as fixed assets.
This fact cannot be delayed.
“It’s basically finished.”
Liu Chenchen replied:
“Only one surface measuring instrument imported from the British TaylorHobson company has not yet arrived, but the expected It will be scheduled until September, and the next semester has already started.”
"Then, have a happy holiday."
Chang Haonan is not a devil after all, and he still has to give him the holiday he deserves.
After seeing off Liu Chenchen who almost skipped out, Chang Haonan also left the office and wandered all the way to the Compressor Research Center not far away——
Because of the campus headquarters, There is really no way to plan another piece of land to build a building, so the experimental projects of the Torch Laboratory are temporarily placed here before moving to a new site in the suburbs.
Fortunately, the Compressor Research Center does not have many people and equipment. Currently, only a group of technicians from the Turbofan 10 project are conducting testing work here.
So there is enough space.
......
When Chang Haonan came to the laboratory, Li Yabo was concentrating on operating a carbon dioxide laser.
The former went over to take a look and found a piece of black CFRP (carbon fiber reinforced resin matrix composite) laminate that had been laid out on the operating table.
It looks like ablation engraving is being done. After more than 20 years, this kind of equipment will evolve into something similar to a CNC machine tool. As long as the parameters are set, it can work fully automatically.
But at this moment, the computer can still only play an auxiliary role, and some manual work is still needed to ensure the accuracy of the operation.
So Chang Haonan just stood behind Li Yabo and watched, and did not speak rashly.
Otherwise, if the latter's hand shakes, a board worth several thousand dollars may be scrapped.
Torch Laboratory does have a lot of money, but it still needs to save where it should.
About half an hour later, Li Yabo, who had some sweat on his forehead, finally ended the laser engraving operation and took the CFRP board off the operating table.
With the naked eye... you can hardly see any difference from before.
So there is a microscope not far away.
After moving to the new laboratory, Chang Haonan will definitely set up a separate electron microscope center. However, the relocation of such large equipment is extremely troublesome, so at the headquarters, we can only use ordinary equipment first. One cap.
Fortunately, the requirements for surface observation of carbon-based composite materials are not demanding, and a good-quality optical microscope can suffice.
Li Yabo was about to take the sample in his hand for testing, and it was only then that he noticed Chang Haonan behind him.
"Teacher?"
Unsurprisingly, he was startled:
"When did you come?"
"Well ...for a while.”
Chang Haonan replied:
"It was probably when you first started burning the board."
"Huh..."
Li Yabo calmed down a little, and then As he walked towards the microscope, he explained:
“I am testing the removal of excess resin-based material by laser ablation.”
“Because in CFRP materials, the thermal and photophysical parameters of the carbon fiber reinforced phase and the matrix phase of the resin material are very different, so after the lamination is completed, laser processing is generally used to selectively remove the matrix phase... ”
Chang Haonan did not interrupt the other party, but just listened quietly.
Although he actually knew what Li Yabo said.
The heat generated by laser processing will preferentially diffuse into the material along the carbon fiber. Since the heat transfer performance and vaporization temperature of carbon fiber are both an order of magnitude higher, when the temperature of laser ablation reaches the vaporization of the resin matrix When exposed to high temperatures, carbon fiber can still remain solid and conduct heat stably.
The principle is somewhat similar to using laser to remove melanin for whitening in medicine.
However, for Li Yabo, a new scientific researcher who has just entered the laboratory, everything is still fresh, which is when the desire to talk is strongest.
"Uh..."
His eloquent voice stopped abruptly.
Then he sighed softly.
Obviously the results of microscope observation are not very satisfactory.
"What's wrong?"
Chang Haonan came to the side and noticed that nearly ten CFRP boards had been piled here.
One of them was placed in a separate bag.
It seems that Li Yabo has spent a lot of time on this experiment.
"Well...that's it. I found that although the carbon fiber will not vaporize along with the resin matrix during the ablation process, as the continuous laser irradiation time becomes longer, it will cause ablation near the incision. The carbon fiber is oxidized.”
"Although the ordered surface measuring instrument has not yet arrived, even with an optical microscope, it can be seen that this oxidation will cause the surface morphology of the carbon fiber material to change, and the performance will also deteriorate."
This In fact, it is difficult to call it an achievement, but considering that Li Yabo returned home after the defense last month, and it has not been long since he returned to school and started the experiment, it can be considered a gratifying progress.
(End of this chapter)