"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 zone, overlap, poor surface quality and low efficiency. ”

However, the use of chemical heat treatment method is easy to cause large stress and deformation of the material, and there are shortcomings such as large energy dissipation and low production efficiency. ”

"If the electroplating process is used, it is easy to produce toxic substances such as cyanide, which endangers human health and will also have environmental pollution problems. ”

"However, a strong pulsed ion beam can accumulate high energy on the surface of a material in a very short period of time, rapidly producing a process of heating, melting and solidification. ”

"The stress wave, shock wave and other physical phenomena 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 surface of the material. ”

It has the advantages of high energy, high efficiency and cleanliness, which avoids the shortcomings of the previous surface modification technology and is an effective means of material surface modification. ”

"That's why we're doing intense pulsed ion beams for surface modification research. ”

For some reason, Dean Yang today described the advantages of strong pulse ion beam surface modification technology for the first time.

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

Behind this emphasis, more should be paid attention to by every researcher in the laboratory.

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

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

"Okay, let's start experimenting. Dean Yang nodded and commanded.

The experiment officially began.

Unlike the previous stage of experimentation, this stage has many fewer steps.

The process parameters are also much lower than those of diode research.

In the first experiment, the acceleration voltage was only 30 kV, the operating current was 30 kA, and the pulse frequency was 0.1 Hz.

By changing the number of pulses, 1, 5, 10, 30, and 50 pulses were selected to perform the pulses separately.

After that, the process parameters are changed and the experiment is repeated.

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

The size of the sample is 20mm×5mm, and the surface needs to be polished with 240#, 400#, 600#, and 800# sandpaper, and then cleaned and dried with absolute ethanol.

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

Although the experimental process is much simpler, the time required for the experiment increases.

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

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

In fact, the microstructure and cross-sectional morphology of this thing are not beautiful at all.

It is mainly composed of α-ferrite and pearlite, although it is quite flat, but Chen Zhou does not feel aesthetic at all.

However, after one pulse, the experimental material is estimated to be even more ugly.

This experiment will take place for a whole day.

And after various tests, the experimental data can be given to Chen Zhou for processing.

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

Before returning to school, he saw a photograph of the surface of the experimental material after 1, 5, and 10 pulses.

As expected, after the surface treatment of the high-pulse ion beam, a crater with a diameter of about tens of microns appeared on the surface of the experimental material.

In particular, the surface under the condition of 5 pulses is completely pitted, and there is no flat place in sight.

After the first pulsed ion beam treatment, there were a large number of molten pits distributed in a network shape, but it was still possible to take a look.

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

Moreover, the distribution of the craters has almost no reticulated structure.

Judging from this small number of experimental phenomena, the intensity of one pulse is not enough, and the crater has just appeared.

At 5 pulses, it is already all "broken".

At 10 pulses, you are on your way to the desired result of the experiment.

Therefore, it can be preliminarily judged that the experiment was carried out quite smoothly.

That is to say, with the increase of the number of pulse treatments, the number of melt 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 of the surface of the material will gradually flatten and smooth.

After returning to Yan University, Chen Zhou came to the library with a computer and a variety of items.

The experiment had already begun, and he didn't feel like he was waiting for the data.

He was ready to take the pace of the experiment himself, as he had done the previous times.

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

There are two main ones.

One is the experiment itself, which is aimed at the research data of the surface modification technology of strong pulse ion beam materials.

One is his speculation, the research data of the strong pulsed ion beam modified on the surface of the material.

Prepare with both hands, grasp with both hands.

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

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

Here, her experimental guesses can be verified.

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

But to Chen Zhou's surprise, the results of this experimental data are a little too ideal, right?

Comparing the pulse treatment results at various frequencies, it is obvious that the surface of the material treated with 30 pulsed ion beams has the least number of pits, the smallest size, and the shallowest crater depth.

Moreover, the network structure disappears completely, and the surface topography shows the most flat and smooth.

At the same time, the thickness of the remelted layer is about 8 μm after 30 pulsed ion beam treatments, and the boundary between the remelting layer and the matrix is obvious.

There are no obvious grain boundaries in the remelt layer, while there are obvious grain boundaries in the matrix.

Perfectly met the expectations of the experiment.

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

Or, following his own guesses, he began to dig deeper.

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

Yang Yiyi was also looking at him, smiling.

It's just that there is a clear smug look in the smile.

Chen Zhou instantly understood that the process parameters of this experiment should be from Yang Yiyi's hand.

"Yiyi, is this your optimized experimental design?"

Yang Yiyi winked at Chen Zhou: "Yes, it's not bad, right?"

Chen Zhou praised sincerely: "Amazing!"

Hearing Chen Zhou's praise, Yang Yiyi's happiness overflowed, which was even happier than when she witnessed the experimental results in the laboratory.

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

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

Before Chen Zhou finished speaking, he heard a fierce cough.

Chen Zhou suddenly closed his mouth, and Yang Yiyi was also holding back a smile on the side.

It's just that Chen Zhou is very strange, thinking that there is only one classmate with a cough?

Why are there so many today?

Could it be that the weather is getting cooler, and everyone is cold?

As everyone knows, these coughing classmates really can't bear it.

They can tolerate that you are a peerless double pride, abusing people in the Academy of Mathematics, abusing people with world-class math problems, but if you feed the dog food, you really can't bear it!

At the same time, the classmate, who used to cough, looked around in surprise.

Then, he saw an empathetic expression......