Volume 1: Student Life Chapter 316: Letter of Recommendation is in Place
After being disturbed by those people in the library, Chen Zhou naturally felt embarrassed to continue being affectionate with Yang Yiyi.
He coughed lightly and turned his attention back to the data in front of him.
With Yang Yiyi's previous preparation, the time Chen Zhou spent on the research on intense pulsed ion beam surface modification was directly reduced by more than half.
He only needs to follow the normal process and add a little of his own thinking to process the data quickly.
[The main reason for the formation of molten pits on the surface of the modified material is that under the action of the high-pulse ion beam, the sub-surface of 30SiMn3MoVA steel is heated first, causing the carbides, grain boundaries, crystallographic defects and other low-melting-point locations with thermophysical differences between the surface and the matrix to dissolve and erupt first, eventually forming molten pits on the surface of the material. ]
While reading this passage, relevant experimental data, as well as photos of the surface microstructure and cross-sectional microstructure under a scanning electron microscope flashed rapidly through Chen Zhou's mind.
"The morphological characteristics of the surface after intense pulsed ion beam treatment are because under the action of the intense pulsed ion beam, the surface of the material instantly accumulates high energy and undergoes a process of rapid heating, melting and cooling, inducing a stress field..."
"Ultimately, the surface of the material undergoes rapid and drastic plastic deformation, forming the morphology we see now."
Chen Zhou thought for a moment, then opened the scanned photo sent by Dean Yang and took a look.
Then, Chen Zhou compared the experimental data again and nodded slowly.
"When an intense pulsed ion beam bombards the surface of a material, its energy is converted into heat energy in a very short time, causing the surface of the material to melt and then cool rapidly."
"Under these conditions, the formation of carbides and the precipitation of the second phase on the surface of the material will be inhibited, which will eventually refine the surface grains and form a remelted layer. The thicker the remelted layer, the higher the surface hardness of the material."
"Comparing the conditions of various process parameters, as the number of pulses increases, the experimental results are all within the expected range."
"In that case, we can skip the part about the surface microstructure and move on to the next step."
The next step Chen Zhou is thinking about is the analysis of corrosion resistance.
A good piece of steel not only needs to be hard enough, but also able to withstand corrosion!
According to the expected settings, Chen Zhou began to integrate and process the data.
Comparative analysis of the potentiodynamic polarization curves of 30SiMn3Mo VA steel before and after intense pulsed ion beam treatment.
At the same time, the Tafel extrapolation method is used to fit the potentiodynamic polarization curve to obtain the changes in corrosion potential and corrosion current with the pulse number, and a list of fitting parameters is obtained.
Charts are the most intuitive representation of data and are an indispensable part of data processing.
After taking a look, Chen Zhou just felt bored.
This kind of data processing, where everything is predictable, is really plain, boring and unpretentious.
He inadvertently turned his head to glance at Yang Yiyi, only to see that the girl was concentrating on looking at the documents in front of her.
Chen Zhou glanced at what Yang Yiyi saw. Oh, this girl was walking in front of him again.
With a slight smile, Chen Zhou turned to look at the chart on the computer and began to speed up his hands.
We must finish processing the data quickly and catch up with Teacher Xiao Yang as soon as possible!
The chart intuitively shows that compared with the original sample, the corrosion potential Ecorr after high pulse ion beam treatment has a positive shift to varying degrees.
This shows that the corrosion tendency of the treated samples is reduced.
The parameters fitted by the Tafel extrapolation method also show that the corrosion current density Icorr of the samples becomes smaller after being treated with high-pulse ion beams.
This indicates that the corrosion rate of the treated samples is reduced.
On the draft paper, Chen Zhou began to write:
[The corrosion potential increased and the corrosion current density decreased. The corrosion resistance of the sample after the surface pulse treatment was enhanced. The highest corrosion potential was -641mV, the corrosion tendency was the lowest, the corrosion current was the lowest at 6.91×10^-4mA/cm2, the corrosion rate was the lowest, and the corrosion current was reduced compared to the original sample. ]
[The data analysis results show that the sample treated with 30 pulses has the best corrosion resistance. ]
This is the data analysis conclusion obtained under the first set of process parameter conditions.
After finishing one set of experimental data, Chen Zhou rushed to the next set of experimental data.
Same approach, same thinking.
As time passed, the pile of draft papers in front of Chen Zhou gradually increased, and the amount of unprocessed data became less and less.
Finally, Chen Zhou breathed a sigh of relief.
“The overall pattern has also emerged.”
After changing to a new piece of draft paper, Chen Zhou habitually clicked twice before starting to write the rule.
【After being treated with high-pulse ion beams, the corrosion resistance of the samples has been improved, but it does not increase with the increase in the number of pulses, and there is a certain degree of repetitiveness. 】
Looking at the text he had written, Chen Zhou thought for a while and continued writing.
[The first set of process parameters can be re-tested in the range of 30 to 33 pulse times; the second set of process parameters...]
This is Chen Zhou’s suggestion, and it is also the only minor adjustment he can make.
This is also Chen Zhou’s attitude towards experiments.
Of course, this is not data that Chen Zhou gave out blindly.
Instead, adjustments and inferences are made during the processing of experimental data.
The improvement of corrosion resistance of 30SiMn3MoVA steel is due to the combined effect of grain refinement and increased content of retained austenite in the surface layer of the sample after pulse treatment.
This austenite is actually γ-Fe, which is produced when the surface structure of the sample changes after high-pulse ion beam treatment.
At the same time, the remelted layer formed after high-pulse ion beam treatment is not only hard but also corrosion-resistant.
Under the combined effect of these changes, the corrosion resistance of the sample surface is improved.
Thinking of this, Chen Zhou wrote down his reasons next to the experimental adjustment parameters given.
[…Within a certain range of pulse times, the thickness of the remelted layer will increase to a certain extent as the number of pulses increases, thereby improving the corrosion resistance of the material.]
After finishing all this, Chen Zhou felt relieved: "The data is finally ready!"
Opening a new page of the Word document on the computer, Chen Zhou began to organize the data processing results .
In a short while, the file is compressed, sent by email, and done!
Next, it is the experimental verification.
Chen Zhou stretched and prepared to see how Yang Yiyi was doing with her research.
But unexpectedly, when he turned his head, he saw Yang Yiyi looking at him with a smile.
Chen Zhou was embarrassed for a moment, then raised his head and said, "Does my handsome face attract you?"
Yang Yiyi didn't say anything, but just made an "evil" expression.
Chen Zhou was about to raise his hand, but Yang Yiyi grabbed his arm first.
There is no way, the meat is in someone else's hands, so beg for mercy.
Just as Chen Zhou thought, after Dean Yang received the results of the experimental data processing, he immediately arranged a new experiment.
The experiment was proceeding in an orderly manner, and Chen Zhou's days were very fulfilling.
But what Chen Zhou didn't know was that somewhere, there was a huge quarrel because of him.
The reason for the "quarrel" is very simple: the joint recommendation letters from several academicians have been in place.
