The Literary Life of a Science Leader

Chapter 183 Grain Growth and Recrystallization Texture (23)

"How about it?"

Director Hao next to him suddenly asked, and Mu Jingchi felt helpless.

"do not know."

He also knew what Director Hao was asking, and it was nothing more than whether Professor Gao's theoretical direction was feasible.In fact, this nickel-based superalloy project team has been established for a long time, but the theoretical direction of the research has not been determined.

In other words, the determined research direction did not go through.

"Theoretical thinking sounds reasonable, but you don't know it in the real experimental stage and calculation stage, and the theory is just a theory."

Sometimes the theory put forward is very good, but the follow-up mathematical calculation encounters difficulties, and the problem of data calculation cannot be solved, or there is no corresponding mathematical tool to solve the difficulties encountered in practice.

In the course of the experiment, more difficulties were encountered.

There are too many aspects involved in material research and development, and the problem of material technology is extremely complicated. Sometimes the material changes inexplicably during the experiment process, resulting in changes in the microscopic organizational structure, but the reason cannot be found.

All kinds of problems will eventually cause a huge gap between reality and theory, and even when the theory is prevailing, there is no room for practical operation.

"You don't like it either?"

At this moment, other material masters began to speak, refuting and refuting the ideas in Professor Gao's research direction, which is quite normal.

Everyone has something they are good at, and other material masters started to ask questions based on the part they are good at, and pointed out various problems in the research direction little by little.

No research direction is foolproof. Without experimental verification, even the best experimental plan may go wrong.

On the contrary, there are theoretical solutions that seem very unreliable but can be verified by experiments.

"I'm not not optimistic, I just don't know." Mu Jingchi's identity is still very upright, in the field of superalloy research, he is really a newcomer.

Although he can also make some suggestions, but more importantly, he came here to learn, laying the foundation for future research on superalloys.

"At least, I think Professor Gao's ideas on crystal grains are very good."

As soon as he heard Professor Gao's research direction, Mu Jingchi knew that he had deeply studied his previous paper on aluminum alloys, because in that paper he mentioned the future of grain growth and other structural changes during recovery and recrystallization. Research bias.

After the recrystallization of the material is completed, new, fine, and undistorted equiaxed grains are formed. Continued heating or holding at isothermal temperature will cause grain growth, causing some performance changes, such as strength, plasticity, and toughness will decrease.

In addition, with grain growth, other structural changes, such as recrystallization texture, will also occur.

Both of these will affect the performance of the material. In the future textbook knowledge, the control and creation of grain growth and crystal texture have begun to achieve the corresponding functions of the material.

It's just how to control the grain growth and crystal texture, which involves more in-depth material science and material technology issues.

Mu Jingchi has not found out yet.

But the line of thinking is correct.

Normal grain growth is a process in which grains grow uniformly under the action of the driving force of interface curvature during the continuous heating or heat preservation process after recrystallization is completed.

In the volume of the metal matrix, the grain size is uniformly distributed and continuously increases.At a certain temperature, the grain size is generally uniform, with a small fluctuation range. As the temperature increases, the average size of the grains increases.

It can be regarded as traceable.

There is also a kind of grain growth, which is abnormal grain growth.

It is the process of uneven grain growth that occurs after the normal and uniform growth of grains under certain conditions.During the growth process, the size of the grains varies greatly, and a few grains grow preferentially, and gradually annex the surrounding small grains, until these preferentially grown grains contact each other, the surrounding fine grains disappear, and all coarse grains are formed. Finish.

This process is also called secondary recrystallization.

If the grain growth is controlled, it can also affect the performance of the material, and the grain itself is also related to the dislocation, which can be said to affect the whole body.

It's not that simple.

In the process of grain growth and secondary recrystallization, long-term annealing and high temperature heating will form a new recrystallization texture.Under the conditions of multiple deformation textures in the recrystallization process, the texture components with favorable growth orientation can grow selectively to form a new recrystallization texture, and the existence and control of the second particle also have an important influence on the development of directional growth .

The formation of recrystallized texture can make the material anisotropic and has an important impact on material properties and applications.

On the one hand, it has beneficial effects. For example, soft magnetic materials have anisotropic magnetism, and the <100> direction of cubic metal is the easy magnetization direction. High magnetic induction intensity can be obtained under a small external magnetic field.

Taking silicon steel sheet as an example, controlling cold rolling deformation and recrystallization annealing temperature can make cold rolled silicon steel sheet obtain two recrystallization textures with easy magnetization directions, namely Gaussian texture {110}<001> and cubic texture { 100}<001>, which can guarantee excellent magnetic properties.

On the other hand, the formation of recrystallization texture has a harmful effect, and the formation of recrystallization texture causes anisotropy of mechanical properties, which is detrimental to the processability and usability of materials.

For example, deep-drawn copper plate is deformed by 90% cold rolling and annealed at 800°C to form a cubic texture {100}<001>, which has directionality, and the plasticity in different directions is different, along the rolling direction and vertical rolling direction, δ=40%, And in the direction of 45° with the rolling direction, δ=75%.

Uneven deformation in all directions results in uneven thickness and uneven edges, causing the product to be scrapped.

"So, Professor Gao still has ideas in this direction."

Mu Jingchi nodded to Director Hao's words, "The idea is good, I think this can be used as a direction, but I don't know the result."

The performance of materials is reflected in the microstructure, mastering the microstructure in the material, modifying or even creating it in a timely manner can change the performance of the material.

So as long as you grasp the internal laws of the material a little bit, you can achieve the purpose of improving performance.

This is true for dislocations, as is grain growth and recrystallization textures, and many more.

Of course, our technology does not allow us to directly manipulate the internal microstructure of materials, so we can only impose external conditions to affect the internal microstructure.

After Mu Jingchi's words fell, Director Hao didn't continue the discussion, and listened carefully to the research discussions between other people and Professor Gao.

As Mu Jingchi, who has just entered the field of superalloy research and development, naturally he will not be the first to stand out. He just listens carefully to the various knowledge about the research and discussion of nickel-based superalloys, and occasionally takes a pen in the small notebook he prepares Jot down something that interests you.

···
the other side.

"My little ancestor, you really don't want to pick it up?"

As Song Xiaoyi's manager, Wu Qingyuan almost knelt down to Song Xiaoyi and asked her to take over the role.

"I really don't accept it."

Song Xiaoyi held a notebook in his hand, and used a signature pen to write and draw in the notebook, which was about the decoration plan of the villa.

The decoration of the villa has come to an end, and Song Xiaoyi is thinking about whether there is anything that needs to be added, or that needs to be discarded.

Certain things exist in the imagination, of course it is very beautiful, but after they are actually implemented in the villa, Song Xiaoyi feels that the placement is so-so, and the effect as imagined has not been achieved.

It's time to replace it.

"Sister Wu, I told you I'm going to take the postgraduate entrance examination, so I won't accept the drama." Song Xiaoyi threw out the words while thinking about it, "Besides, the script you brought me is too bad, the heroine's behavior is totally illogical, The lines have no brains, if I really want to continue acting according to this setting, I will throw up myself."

Song Xiaoyi and Mu Jingchi stayed together and were also influenced by each other.

When watching movies and TV shows together in the evening, Mu Jingchi would always say something to Song Xiaoyi, focusing on the illogical parts of the movies and TV shows, and the character settings were simply untenable.

Mu Jingchi won't say it for martial arts people, but he will definitely say it for modern cities.

Therefore, Song Xiaoyi gradually began to study the script.

"You don't care if she has logic, as long as she has money to make, 5000 million!" Wu Qingyuan stretched out her palm and showed five fingers, "It's not 500 million!"

Song Xiaoyi shrugged, "I'm not short of money!"

"Yes, pet!"

She immediately wrote it down in a small notebook, "It's really deserted in the villa with only me and him living in it. Even if the aquarium and those potted plants in his house are moved there, it still lacks some vitality."

"It's good to keep pets, cats and dogs."

"Also, you can change to a bigger aquarium, the ecology of the aquatic plants will be better, and there will be more varieties of fish."

Song Xiaoyi nodded while writing.

"Okay, this urban movie character has no logic, PASS." Wu Qingyuan followed Song Xiaoyi's train of thought, "Then this costume drama is always okay? This character's actions, behaviors and words are very good, and there are no logical problems. How do you do this?" Don't accept it?"

"There's a kiss scene in it, I'm sure I won't accept it!"

Song Xiaoyi flipped through the pages of her notebook. Taking the opportunity to turn the page, she glanced at the name of the costume drama, and opened her mouth to answer, "I promised my boyfriend that I won't accept any kissing scenes!"

Wu Qingyuan patted his forehead, feeling a little helpless.

This is good, many scripts are missed.It is impossible for her to discuss with Mu Jingchi to allow Song Xiaoyi to film a film and television drama with a kissing scene, this is unrealistic.

"Sister Wu, don't pick plays for me, I really won't take plays for the time being." Song Xiaoyi faced Wu Qingyuan, "I want to seriously prepare for the postgraduate entrance examination, as for taking plays, wait until after I graduate, I'm nothing at that time The play is accepted."

"All right!"

Looking at Song Xiaoyi's expression, Wu Qingyuan also understood the other party's intentions, and stopped entangled.

"What about variety shows?"

Song Xiaoyi's eyes lit up, and he said with a smile, "Variety shows are available."

Wu Qingyuan's smile suddenly rose, "There just happens to be a variety show, do you want to go?"

"What program."

"Happy Camp."

(End of this chapter)