The Literary Life of a Science Leader

Chapter 64 Dislocation Theoretical System
What is a dislocation?

It is well known that the actual strength of a crystal is much lower than its theoretical strength.

The so-called actual strength of the crystal is the critical shear stress of the single crystal measured experimentally. This value is generally 10-4~10-8G, and G is the shear modulus of the crystal.The theoretical strength is the strength calculated according to the rigid-slip model of the complete crystal.

The rigid-slip model of crystals was accepted before, but it was later found that the theoretical strength of crystals is at least three orders of magnitude higher than the actual strength.

The huge difference between the theoretical strength and the actual strength forces people to abandon the rigid-slip model of the complete crystal.

It is speculated that there must be some kind of defect in the crystal, which not only causes stress concentration, but also the atoms in the defect area are in an unstable state, so it is easy to move.

In this way, the slipping process of the crystal is that the local slip occurs at the defect first, and then the local slip area continues to expand.

And this kind of defect that causes local slip is called a dislocation!

It seems that dislocation is just a little defect in the material, but in fact it plays a very important role, and it can be said that it is a bottomless topic to continue researching.

Dislocations affect the work hardening of crystals, and the annealing softening of metal ash is also related to dislocations. Dislocations can reduce the elastic modulus of crystals, increase internal friction, and affect the strengthening of alloys.

If dislocations can be controlled, the actual strength of the crystal can be greatly improved and the gap between it and the theoretical strength can be narrowed.

This is Mu Jingchi's current research path.

As these graduate students thought, dislocations are really complicated, and they study the motion of atoms.Atoms cannot be manipulated artificially, so dislocations are complex and difficult.

If it was the former Mu Jingchi, he would never challenge such complicated theories and subjects, and would honestly follow the direction of his mentor.

But Mu Jingchi, who has already accommodated "Basics of Materials Science (2069 Edition)", already has this qualification.

In the year 2069 in the future, dislocation theory has developed somewhat further.

And it all comes down to one man, Thompson.

He has a very in-depth research on dislocations, published many theories about dislocations, and finally even used a dislocation equation to connect all the dislocation theories in series to construct a complete Thompson dislocation theory system.

That equation, also known as the Thompson dislocation equation.

These all belong to Mu Jingchi now.

In order to develop a new type of high-strength aluminum alloy in the existing pattern, then this dislocation theory system is necessary.Without the support of this dislocation theory system, even if it is explained by luck, it would be horrifying.

It’s not convenient either. You can’t explain every material development by luck, right?

"Okay, you will all have this plan."

Because this is just an experimental plan, it seems a bit rough compared to a dedicated and detailed paper.Mu Jingchi quickly read through the content, "You don't need to rush to do experiments these days, first look for monographs and literature on dislocation, and analyze it in combination with my experimental plan."

"When you are ready, we will use experiments to verify and analyze."

It is impossible to use any theory out of hand, and that is unreasonable.And how the theory came about also needs to be supported by data display, which is not ambiguous at all.

What Mu Jingchi presents now is Theory I in Thompson's dislocation theory system.

This theory has been verified in 2069, so it is directly displayed in the textbook, in the form of a theorem.As for its source, how Thompson discovered it and how it was verified is unknown at all.

And this is what Mu Jingchi needs to do now, and it is also what he is going to do in his next scientific research.

If the development, verification, and preliminary application of this theory are all completed by Mu Jingchi, then this becomes Mu Jingchi's Dislocation Theory I.Then there will be the following II, III, IV, V.

It can be said that the general direction of Mu Jingchi's topic this time is the research and development of high-performance aluminum alloys, but in fact it is the establishment of a dislocation theory system. As long as this dislocation theory system is built, then high-performance aluminum alloys will also It will be a matter of course.

After arranging tasks for the four master students and instructing Ai Xiaosheng, Mu Jingchi ended the discussion.

···
"You are too simple here."

In the office next to Mu Jingchi's new office, which is Professor Tian's office, he is learning from Professor Tian as a listener and learner.

"You can't arrange the teaching rhythm according to your own ideas. You have to put yourself in their shoes and consider according to their acceptance and learning abilities."

Professor Tian still has a lot of ideas about Mu Jingchi’s teaching PPT.

It is undeniable that Mu Jingchi sorted out the contents and knowledge of the teaching plan about "Material Science Basics" in an orderly manner, grasped the connection between knowledge, and allowed students to review old knowledge while learning new knowledge.

But it is too simple.

For a genius like Mu Jingchi, there is naturally no pressure to learn, whether it is the absorption of new knowledge or the connection of old knowledge, he can do it very well.

But for ordinary students, too simple teaching plans and too divergent way of thinking are a bit difficult.

Even in Huaqing University, there are students with different degrees of mastery.

"Okay, Professor, I see."

Mu Jingchi nodded frequently. He still listened to Professor Tian's guidance, and he didn't think too highly of himself.In terms of teaching, he is still a newcomer, and following the guidance of the boss will save time and energy.

After all, he still lacks time and energy, and he still needs to keep an eye on the project.

"You have a good grasp of the content, which are the key points to see clearly and have a purpose. However, the rhythm of teaching may not be clear without the real class, so many places are too simple and diffuse."

"It's not a big problem. You'll understand after just a few lessons with me."

Professor Tian mainly encouraged Mu Jingchi. As a teaching assistant, he has done a good job.

"I'll go back and change it."

···
"Mom, why are you here?"

Song Xiaoyi opened the door for her mother, "Didn't you say to stay at home for a few more days to accompany Dad?"

Mother Song pushed the luggage into the room, and closed the door with one hand.

"Aren't I afraid that you won't get used to living alone?"

"No, Yu'er has been living with me these days and just left today." Song Xiaoyi poured some water and handed it to her mother, "You are staying with me here in Yanjing, aren't you afraid that my father will be lonely at home?"

"Why don't you go back to your hometown to accompany dad." Song Xiaoyi persuaded his mother, "I'm in the second semester of my junior year and I'm about to graduate. Don't you worry about me?"

She didn't know Mu Jingchi before, and she didn't fall in love, so she wasn't worried at all.

But now, if she wants to pursue Mu Jingchi, her actions and habits will definitely change. If she continues to live with her mother, it will be easy for her to find out the clues.

So, Song Xiaoyi persuaded her mother to go back to her hometown.

(End of this chapter)