Xueba starts with change

Chapter 315 Yang Yiyi's Strength
"According to the surface treatment technology of high-energy beam sources such as traditional laser beams and continuous ion beams, there will be characteristics such as large heat-affected zones, overlapping joints, poor surface quality, and low efficiency."

"The chemical heat treatment method is easy to cause large stress and deformation of the material, and has the disadvantages of large energy dissipation and low production efficiency."

"If the electroplating process is used, it is easy to produce toxic substances such as cyanide, endangering human health, and there will also be environmental pollution problems."

"However, the intense pulsed ion beam can accumulate high energy on the surface of the material in a very short period of time, and rapidly produce changes in heating, melting and solidification."

"The physical phenomena such as stress waves and shock waves generated in this process have made a very special modification treatment on the surface of the material, and finally improved the corrosion resistance, wear resistance, hardness and strength of the material surface."

"It also has the advantages of high energy, high efficiency, and cleanliness, and avoids the shortcomings of previous surface modification technologies. It is an effective means of surface modification of materials."

"That's why we're working on surface modification techniques with intense pulsed ion beams."

For some reason, Dean Yang gave an unprecedented talk about the advantages of the intense pulsed ion beam surface modification technology.

After Chen Zhou listened, he faintly felt that Yang Yiyi's guess might be correct.

Behind this emphasis, more attention should be drawn to the attention of every scientific researcher in the laboratory.

"Are the experimental materials ready?" Dean Yang looked at Peng Jia.

Peng Jia responded immediately: "It's ready, and the entire experimental device has been checked."

"Okay, let's start the experiment." Dean Yang nodded and ordered.

The experiment officially begins.

Different from the experiment in the previous stage, there are many steps missing in this stage.

Compared with the research of diodes, the process parameters are also much lower.

In the process parameters of the first experiment, the accelerating voltage is only 30kV, the working current is 30kA, and the pulse frequency is 0.1Hz.

通过改变脉冲次数，选取1、5、10、30、50次，分别进行脉冲。

Thereafter, the process parameters were changed and the experiment was repeated.

Of course, before this, it is necessary to process the experimental material, that is, the 30SiMn2MoVA steel bar.

试样的尺寸是20mm×5mm，表面还需依次经过240#、400#、600#、800#砂纸打磨抛光后，用无水乙醇清洗并吹干。

For the materials after the experiment, it is necessary to use the electrochemical workstation for corrosion resistance test and potentiodynamic polarization curve test.

Although the experimental process is much simpler, the time consumption of the experiment is increased.

After looking at the various parameters on the console for a while, Chen Zhou shifted his gaze to the scanned photos of the original experimental materials.

After the original sample was ground, polished, and corroded with 5% nitric acid alcohol, the original microstructure and cross-sectional morphology were observed by scanning electron microscope.

In fact, the microstructure and cross-sectional shape of this thing are not good-looking at all.

It is mainly composed of α-ferrite and pearlite. Although it is fairly flat, Chen Zhou feels that it has no aesthetic feeling at all.

However, it is estimated that the experimental materials after one pulse will not be as good as this, and will be even uglier.

This experiment will last a whole day.

Moreover, the experimental data can only be given to Chen Zhou after various tests for him to process.

So, after staying in the laboratory all morning, Chen Zhou had lunch and went back to school.

Before going back to school, he saw photos of the surface of the experimental material after 1 pulse, 5 pulses and 10 pulses.

It is in line with the experimental expectations. After the surface treatment by the high-pulse ion beam, the surface of the experimental material has a molten pit with a diameter of about tens of microns.

Especially the surface under the condition of 5 pulses is completely bumpy, and there is no flat place to be seen.

After one pulsed ion beam treatment, although there are still a large number of melting pits distributed in a network, they can still be seen at any rate.

However, scattered and independently distributed melting pits can already be seen on the surface of the material after 10 pulsed ion beam treatments.

Moreover, the distribution of melting pits has almost no network structure.

Judging from this small amount of experimental phenomena, the strength is not enough for one pulse, and the melting pit has just appeared.

By the time of 5 pulses, it has all been "broken".

At 10 pulses, it is moving towards the desired result of the experiment.

Therefore, it can be preliminarily judged that the experiment went smoothly.

That is to say, as the number of pulse treatments increases, the number of melting pits gradually decreases, the size becomes smaller, and the depth becomes shallower, and the irregular network structure gradually disappears, and presents an independent distribution state.

It can also be expected that after multiple pulse treatments, the microscopic area on the surface of the material will gradually become smoother.

After returning to Yanda, Chen Zhou brought his computer and other items to the library.

The experiment has already started, and he doesn't seem to be waiting for the experimental data.

He is going to control the rhythm of the experiment by himself like the previous few times.

After the computer was connected to the library's network, Chen Zhou began to search for relevant literature.

There are mainly two aspects.

One is the experiment itself, which is the data for the research on the surface modification technology of intense pulsed ion beam materials.

One is his conjecture, research data on the surface modification of materials with intensely pulsed ion beams.

Prepare with both hands, grasp with both hands.

Naturally, Jebov's conjecture and the research on the optimal design of accelerator diodes mentioned by Dean Yang were briefly put aside by him.

Yang Yiyi did not come back with Chen Zhou, but stayed in the laboratory.

Only here can she verify her experimental guess.

Two days later, Chen Zhou got the experimental data and began to process the data.

But what surprised Chen Zhou was that the results of the experimental data were a bit too ideal, right?
Comparing the pulse processing results at various frequencies, it is obvious that the surface of the material after 30 pulsed ion beam treatments has the least number of melting pits, the smallest size, and the shallowest depth of melting pits.

Moreover, the network structure disappears completely, and the surface topography shows the smoothest.

At the same time, the interface morphology after 30 times of pulsed ion beam treatment shows that the thickness of the remelted layer is about 8 μm, and the boundary with the matrix is ​​obvious.

There are no obvious grain boundaries in the remelted layer, but obvious grain boundaries in the matrix.

Perfectly met the experimental expectations.

Chen Zhou is probably "really" processing the experimental data now, because there is not much room for adjustment.

Or, according to his guess, he began to dig deeply.

Thinking of this, Chen Zhou turned his head slightly to look at Yang Yiyi who was sitting beside him.

Yang Yiyi was also looking at him with a smile on her face.

However, there was a hint of smugness in the smile.

Chen Zhou instantly understood that the technological parameters of this experiment should have been created by Yang Yiyi.

"Yiyi, is this your optimized experimental design?"

Yang Yiyi blinked at Chen Zhou: "Yeah, not bad, right?"

Chen Zhou praised sincerely: "Amazing!"

Hearing Chen Zhou's praise, Yang Yiyi's happiness was beyond words, and she was happier than witnessing the experimental results in the laboratory.

"That must be, don't you see who I am!"

"Yes yes yes, you are the invincible beautiful girl Xiao Yang teacher, you are..."

Before Chen Zhou finished speaking, he heard a violent coughing sound.

Chen Zhou immediately shut his mouth, while Yang Yiyi was holding back a smile.

However, Chen Zhou was very strange, thinking that there was only one classmate who was coughing?
Why are there so many today?
Is the weather turning cold and everyone is catching a cold?
As everyone knows, these coughing students really can't stand it anymore.

They can tolerate that you are peerless twins, abusing people in the Mathematical Institute, and abusing people with world-class math problems, but if you feed dog food again, they really can't bear it!
At the same time, the classmate who used to cough looked around in surprise.

Then, he saw a sympathetic expression...

(End of this chapter)