Chapter 847 Carbon Fiber Reinforced Resin Matrix Composites

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 Beijing until early July.

At this time, the enthusiasm for proving the Poincare conjecture has declined a lot——

One reason is that theoretical mathematics is far away from life after all. As time goes by, people will naturally not continue to pay attention to a topic they do not understand.

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

After all, Chang Haonan had appeared once in an interview with CCTV, but Perelman simply did not find such a person.

As a result, the smooth combo of "lecturing - awarding awards - adding titles" that was supposed to be performed got stuck at the first step.

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

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

Even without the prover's personal lecture, 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 does not have a particularly strong motivation to pull these two people out.

As for mathematicians, having a weird temper is more in line with people's stereotype.

If it were too normal, the filter would be shattered.

In short, when Chang Haonan returned to the capital again, the commotion he caused was relatively small...

"Professor Chang, I want to take a vacation..."

On the first day that Chang Haonan returned to work, Liu Chenchen placed the work report of the period on his desk with a look of despair on his face, and then made a request.

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

But the boss had specifically assigned her a task before she left, so there was no way she would just quit halfway.

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

Finally made it through.

"can."

Chang Haonan looked at the haggard Liu Chenchen and knew that she had been suffering recently, so he agreed without hesitation:

"But before you go on vacation, you have to register the things on the list that Li Yabo gave you earlier."

About three months ago, Li Yabo expressed his desire to study topics in the field of composite material microstructures, so he ordered a large number of equipment and experimental materials.

Now most of the things have arrived, and many of them need to be registered as fixed assets.

This fact really cannot be delayed.

“It’s basically done.”

Liu Chenchen replied:

"Only one surface measuring instrument imported from the British company Taylor Hobson has not yet arrived, but that is expected to be produced in September, and the next semester has already started."

"Have a nice vacation then."

After all, Chang Haonan is not a devil, so he should be given 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 there is no way to allocate a piece of land for building a building at the main campus, the Torch Laboratory's experimental projects are temporarily placed here before moving to a new site in the suburbs.

Fortunately, there are not too many people and equipment in the Compressor Research Center. Currently, only a group of technicians from the WS-10 project are conducting testing work here.

So there is enough space.

……

When Chang Haonan came to the laboratory, Li Yabo was operating a carbon dioxide laser with great concentration.

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 looks like ablative engraving.

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

But at the moment, computers 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 without saying anything 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 money where it can.

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

With the naked eye... I can hardly tell 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 in the headquarters, he can only use ordinary equipment for the time being.

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

Li Yabo was just about to take the sample in his hand for testing when he noticed Chang Haonan behind him.

"teacher?"

Not surprisingly, he was taken aback:

"When did you come?"

"Well... it's been a while."

Chang Haonan replied:

"It was probably when you first started burning the boards."

"call……"

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

“I am testing laser ablation for the removal of excess resin-based material.”

"Because in CFRP materials, the thermal and optical properties of the carbon fiber reinforcement phase and the resin material matrix phase are very different, so after the ply 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 everything Li Yabo said.

The heat generated by laser processing will preferentially diffuse into the interior of the material along the carbon fiber. Since the heat transfer performance and vaporization temperature of carbon fiber are an 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 in medicine to remove melanin for whitening.

However, for Li Yabo, a budding researcher who had just entered the laboratory, everything was still new, and this was the time when he had the strongest desire to talk.

"Uh……"

His endless chattering came to an abrupt halt.

Then he sighed softly.

Obviously, the results of microscopic observation are not very satisfactory.

"What's wrong?"

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

One of them was placed in a bag by itself.

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 becomes longer, the carbon fiber near the ablation cut will be oxidized."

"Although the surface measuring instrument we ordered has not arrived yet, even with an optical microscope, we can see that this oxidation will cause the surface morphology of the carbon fiber material to change, and the performance will deteriorate accordingly."

It is actually difficult to call this an achievement, but considering that Li Yabo went back home after his 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.