Volume 1: Student Life Chapter 315 Yang Yiyi's Strength
"According to traditional high-energy beam source surface treatment technologies such as laser beams and continuous ion beams, there are characteristics such as large heat-affected zones, overlaps, poor surface quality, and low efficiency."
"The chemical heat treatment method is likely to cause greater stress and deformation in the material, and has disadvantages 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 is harmful to human health and will also cause environmental pollution problems."
"However, an intense pulsed ion beam can accumulate high energy on the surface of a material in a very short time, rapidly producing a process of heating, melting and solidification."
"The physical phenomena such as stress waves and shock waves generated in this process have modified the surface of the material in a very special way , ultimately improving 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, avoiding the shortcomings of previous surface modification technologies and is an effective means of material surface modification."
"That's why we are conducting research on surface modification techniques using intense pulsed ion beams."
For some reason, Dean Yang talked about the advantages of intense pulsed ion beam surface modification technology for the first time today.
After listening to this, Chen Zhou felt that Yang Yiyi's guess might be correct.
Behind this emphasis, more attention should be paid to it 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 and is ready."
"Okay, let's start the experiment." Dean Yang nodded and gave the order.
The experiment officially begins.
Unlike the previous stage of the experiment, this stage has fewer steps.
The process parameters are also much lower than those of diode research.
In the process parameters of the first experiment, the acceleration voltage was only 30kV, the working current was 30kA, and the pulse frequency was 0.1Hz.
By changing the pulse times, 1, 5, 10, 30, and 50 times were selected for pulses respectively.
Afterwards, the process parameters were changed and the experiment was repeated.
Of course, before that, the experimental material, that is, 30SiMn2MoVA steel bars, needs to be processed.
The size of the sample is 20mm×5mm, and the surface needs to be polished with 240#, 400#, 600#, and 800# sandpaper in sequence, and then cleaned with anhydrous ethanol and blown dry.
For the materials after the experiment, an electrochemical workstation is required to perform corrosion resistance tests and potentiodynamic polarization curve tests.
Although the experimental process is much simpler, the time spent on 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 and polished, and then corroded with 5% nitric acid alcohol, the original microstructure and cross-sectional morphology were observed by scanning electron microscopy.
In fact, the microstructure and cross-sectional morphology of this thing are not good-looking at all.
It is mainly composed of α-ferrite and pearlite. Although it is relatively smooth, Chen Zhou feels that it is not beautiful at all.
However, the experimental materials after undergoing one pulse will probably be even worse than this and will be even uglier.
This experiment will last a whole day.
Moreover, the experimental data can only be given to Chen Zhou for processing after various tests.
So, after spending a morning in the laboratory, Chen Zhou had lunch and returned to school.
Before returning to school, he saw surface photos of experimental materials after being treated with 1 pulse, 5 pulses, and 10 pulses.
This is in line with the experimental expectations. After high-pulse ion beam surface treatment, molten pits with a diameter of about tens of microns appeared on the surface of the experimental material.
Especially the surface under 5 pulse conditions is completely bumpy, with no flat area to .
After one pulsed ion beam treatment, although there are still a large number of molten pits distributed in a network, at least you can still take a look at it.
However, after 10 pulsed ion beam treatments, scattered and independently distributed melt pits can be seen on the surface of the material.
Moreover, the distribution of the melt pits has almost lost its reticular structure.
Judging from these few experimental phenomena alone, the intensity of a single pulse was not enough and the molten pit only just appeared.
After 5 pulses, everything is "broken".
When there are 10 pulses, we are heading towards the desired .
Therefore, we can preliminarily judge that the experiment went smoothly.
That is to say, with the increase in the number of pulse treatments, the number of molten pits gradually decreases, the size becomes smaller, and the depth becomes shallower. The irregular network structure gradually disappears and presents an independent distribution state.
It can be expected that after multiple pulse treatments, the microscopic area on the surface of the material will gradually become smooth.
After returning to Yanda, Chen Zhou went to the library with his computer and other necessary items.
The experiment has already begun, and he doesn't want to just wait for the experimental data.
He planned to control the pace of the experiment himself, just like he had done in previous times.
After connecting the computer 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 data on the research of intense pulsed ion beam material surface modification technology.
One is his speculation on the research data of intense pulsed ion beams for surface modification of materials.
Be prepared for both situations and grasp both.
Naturally, the Jebov conjecture and the optimization design research of the accelerator diode just mentioned by President Yang were briefly put aside.
Yang Yiyi did not follow Chen Zhou back, but stayed in the laboratory.
Only here can her experimental hypothesis be verified.
Two days later, Chen Zhou got the experimental data and began to process it.
But what surprised Chen Zhou was that the results of the experimental data were a little too ideal.
Comparing the pulse treatment results at various frequencies, it can be clearly seen that after 30 times of pulse ion beam treatment, the material surface has the least number of molten pits, the smallest size, and the shallowest molten pit depth.
Moreover, the reticular structure completely disappears, and the surface morphology appears to be the smoothest and flattest.
At the same time, after 30 pulsed ion beam treatments, the thickness of the remelted layer is about 8 μm, and the boundary with the substrate is obvious.
There are no obvious grain boundaries in the remelted layer, but there are obvious grain boundaries in the matrix.
It perfectly met the experimental expectations.
Chen Zhou is probably now "really" processing the experimental data, because there is not much room for adjustment.
Or, he started digging deeper according to his own guess.
Thinking of this, Chen Zhou slightly turned his head and looked at Yang Yiyi who was sitting next to him.
Yang Yiyi was also looking at him with a smile on her face.
However, there was an obvious hint of pride in that smile.
Chen Zhou instantly understood that the process parameters of this experiment should have come from Yang Yiyi's hand.
"Yiyi, is this the experimental design you optimized?"
Yang Yiyi blinked at Chen Zhou: "Yeah, not bad, right?"
Chen Zhou praised sincerely: "Amazing!"
Hearing Chen Zhou's praise, Yang Yiyi was so happy that she couldn't express it in words. This made her happier than witnessing the experimental results in the laboratory with her own eyes.
"Of course you should. Look at who I am!"
"Yes, yes, you are the invincible beauty Miss Yang, you are..."
Before Chen Zhou finished speaking, he heard a violent coughing sound.
Chen Zhou immediately shut his mouth, and Yang Yiyi was also trying hard to hold back her laughter.
But what Chen Zhou found very strange was that he thought there was only one student who was coughing.
Why are there so many today?
Is it because the weather is getting colder that everyone is catching a cold?
Little did they know that these students who were coughing really couldn't bear it any longer.
They can tolerate you being the two most outstanding talents, bullying others in the School of Mathematics and the School of Physics, and bullying others with world-class mathematical problems, but they really can't tolerate you feeding them dog food!
At the same time, the student who used to cough looked around in surprise.
Then, he saw a group of people who felt the same way...
