Chapter 847 Carbon Fiber Reinforced Resin-Based Composite Materials

In order to avoid the limelight and follow up on the M88 engine cooperation project, Chang Haonan stayed in Shengjing for nearly a month and did not return to Beijing until early July.

During this time, the enthusiasm for proving the Poincare conjecture has dropped a lot -

Firstly, theoretical mathematics is far away from life after all. As time goes by, people will naturally not pay attention to a topic they don't understand.

Secondly, the two authors of the paper disappeared at the same time after the mathematical community confirmed that the proof process was valid.

Chang Haonan at least showed up once in an interview with CCTV, and Perelman simply found no such person.

As a result, the silky combo of "lecture-award-add title" that was supposed to be played was stuck at the first step.

Even if the media wanted to follow up on the report, they couldn't find the focus.

Of course, in the final analysis, although the proof process of the Poincare conjecture is very long, it is not difficult to understand.

Even without the personal lecture of the prover, many people can still understand it.

Unless you want to integrate the theoretical tools in the paper, it will be difficult.

So objectively speaking, the academic community has no strong motivation to pull these two people out.

As for mathematicians, a little bit of a weird temper is more in line with people's stereotypes.

If it is too normal, the filter will be shattered.

In short, when Chang Haonan returned to Beijing 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.

In fact, as a scientific research unit affiliated to the school, the Torch Laboratory has at least one month of winter and summer vacations in theory.

But the boss specially assigned tasks before leaving, and she couldn't just quit halfway.

So she was bombarded by phone calls, emails and letters for more than half a month.

Finally made it through.

"Okay."

Chang Haonan looked at Liu Chenchen, who looked haggard, and knew that he had suffered a lot recently, so he agreed very straightforwardly:

"But before you go on vacation, you 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 the topic of microstructure of composite materials, so he ordered 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 can't be delayed.

"Basically, it's done."

Liu Chenchen replied:

"Only a surface measuring instrument imported from Taylor Hobson in the UK has not arrived, but it is expected to be produced in September, and the next semester has already started."

"Well, have a happy vacation."

After all, Chang Haonan is not a devil, and he still has to give him the vacation he deserves.

After seeing off Liu Chenchen, who almost jumped out, Chang Haonan also left the office and strolled to the Compressor Research Center not far away.

Since the school headquarters could not plan a piece of land to build a building, the experimental projects of the Torch Laboratory were temporarily placed here before moving to a new site in the suburbs.

Fortunately, there are not many people and equipment in the Compressor Research Center. Currently, only a group of technicians from the WS-10 project are conducting testing 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 leaned over to take a look and found a piece of black CFRP (carbon fiber reinforced resin-based composite material) laminate that had been woven on the operating table.

It looked like ablation engraving was being performed.

In more than 20 years, this kind of equipment will evolve into something similar to a CNC machine tool, and it can work fully automatically as long as the parameters are set.

But at this moment, the computer can 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 thousands of dollars may be scrapped.

The Torch Laboratory is indeed wealthy, but it still needs to save some money where it should be saved.

About half an hour later, Li Yabo, with a little sweat on his forehead, finally finished the laser engraving operation and took the CFRP plate off the operating table.

With the naked eye... basically there is no 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, but the relocation of such large equipment is extremely troublesome, so in this part of the headquarters, only ordinary equipment can be used for the time being.

Fortunately, the requirements for surface observation of carbon-based composites are not harsh, and a relatively good quality optical microscope can meet them.

Li Yabo was about to take the sample in his hand for testing, and only then did he notice Chang Haonan behind him.

"Teacher?"

Not surprisingly, he was startled:

"When did you come?"

"Well... a while ago."

Chang Haonan replied:

"Probably when you just started burning the board."

"Huh..."

Li Yabo calmed down a little, then walked towards the microscope and explained:

"I am testing the removal of excess resin-based materials by laser ablation."

"Because in CFRP materials, the thermal and photophysical parameters of the carbon fiber reinforcement phase and the resin material matrix phase are very different, so after the plying is completed, laser treatment 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 all that Li Yabo said.

The heat generated by laser processing will preferentially diffuse along the carbon fiber into the material. Since the heat transfer performance and vaporization temperature of carbon fiber are one order of magnitude higher, when the temperature of laser ablation reaches the vaporization temperature of the resin matrix, the carbon fiber can still remain in a solid state and conduct heat stably.

The principle is somewhat similar to the use of laser to remove melanin for whitening in medicine.

However, for Li Yabo, a new scientific research novice who has just entered the laboratory, everything is still in a fresh state, and it is the time when the desire to talk is the strongest.

"Uh..."

His endless voice stopped abruptly.

He then sighed softly.

It is obvious that the results of microscopic observation are not very satisfactory.

"What's wrong?"

Chang Haonan came to the side and noticed that there were nearly ten CFRP plates piled up here.

One of them was placed in a bag alone.

It seems that Li Yabo has spent a lot of time on this experiment.

"Well... it's like this. I found that although the carbon fiber will not vaporize like the resin matrix during the ablation process, as the laser irradiation time increases, the carbon fiber near the ablation cut will be oxidized."

"Although the surface measuring instrument ordered has not arrived yet, 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 is actually difficult to call an achievement, but considering that Li Yabo went home after the defense last month, it has not been long since he returned to school to start the experiment, so it can be regarded as a gratifying progress.