"What's wrong, you don't seem to be in a good mood?"

Song Xiaoyi looked at Mu Jingchi with a calm face, leaned beside him, and asked cautiously.

Because the decoration of the villa has not been done yet, Mu Jingchi still lives in this Shengjing community, and as soon as he arrived home, Song Xiaoyi came from next door.

"No, just a little frustrated. ”

Mu Jingchi took a deep breath, and then slowly exhaled it, "The research project in Yangangyan is a little more complicated than I thought before, and I have suffered a little twist and turn. ”

Looking at Song Xiaoyi, Mu Jingchi waved his hand, "It's nothing, don't worry." ”

"Are you having trouble at work?"

Although Song Xiaoyi doesn't understand her boyfriend's material career, she can still care about the relationship occasionally.

"yes!"

Mu Jingchi lay on the sofa, stretched his waist, and stretched his body, "This is the first time I have encountered difficulties in the direction of theoretical research and have been directly beaten back." ”

Time goes back.

In the theoretical research room, Professor Gao first expounded his research ideas, although he encountered opposition from other bigwigs, but this opposition is not a bad thing, and it is not opposition for the sake of opposition, but opposition for the problems in the research direction.

The starting point for this opposition is to allow the development of this nickel-base superalloy to proceed smoothly.

Therefore, Professor Gao is not angry, he knows the shortcomings of his research ideas, and these people point them out one by one at this time, so that the next time he holds a seminar, his ideas will be clearer and his research plan will be better.

Later, Professor Xu also began to publish his own research ideas.

It is not the same as Professor Gao's thinking, but it is also making a fuss about heat treatment, although it seems to belong to the same path in the general direction, but the direction of the final path is not the same.

Mu Jingchi still listened very carefully, and took a pen to take notes.

Professor Xu's research direction has also been refuted by the bigwigs, and Professor Gao has also found many problems in it, refuted the inadmissible part with profound theoretical knowledge, and explained the incorrectness of the research direction.

Professor Xu naturally did not give up, he also had his own ideas, and the ideas seemed to be completely tenable, so he had a research debate with the bigwigs present.

Whenever this happens, Mu Jingchi is always the most meticulous and does not relax at all.

Because so many people present are immersed in the superalloy project, their theoretical knowledge, experimental experience and research ideas are extremely profound.

Moreover, the knowledge system has been built, and often a small problem can involve more problems, which in turn leads to an explosion of problems in the research content.

There are all kinds of problems.

At this time, Mu Jingchi's thinking should also follow the words of these people, and their words are based on material knowledge, and they are not groundless and arbitrary.

Following the words of these people, Mu Jingchi slowly figured out the thickness and breadth of the theories of these bigwigs, and sometimes Mu Jingchi would also think about the problems they described.

Is there really no way to solve it?

Or can you solve it with another way of thinking?

If it is not solved, will it really have that big impact?

All in all, the argument was very lively, but it had a lot to say. Although their age is already middle-aged and upward, Mu Jingchi can see the vigorous research vitality on their faces, and everyone exudes a kind of vitality for scientific research, and there is no more twilight because of age.

"Dr. Mu, tell me what you think. ”

Disputes are always stagnant, and one by one the bigwigs express their own thoughts and ideas, and determine their own research directions, but they can't convince everyone.

I can only slowly check and fill in the gaps to make my research ideas more perfect.

At this time, Director Hao opened his mouth and asked Mu Jingchi to speak.

Mu Jingchi's eyes glanced around, and seeing that many eyes were looking at him, he no longer maintained the role of an audience, stood up, and projected the prepared information.

"Since Director Hao asked me to talk about it, then I will talk about my research ideas, and I hope that you will be able to talk about the shortcomings. ”

In his own research group, Mu Jingchi is the person in charge, and there is absolutely no such statement.

"My idea is to make a hypothetical model of the thermodynamics of the material according to the required properties of the nickel-based superalloy, and determine the equilibrium state of the phase of the alloy at a certain temperature and composition according to the Gibbs free energy curve of the alloy phase of the hypothetical model and the thermodynamic conditions of phase equilibrium, and then... ”

Mu Jingchi's thinking is very easy to understand when simplified.

Based on the mechanical properties to be achieved, the microstructure model of the material is simulated by the computer, and the phase diagram is constructed, which is used as a reference to use the external conditions to achieve the simulated phase equilibrium state.

While there is certainly a gap between practical and theoretical simulations, this is still an approach.

This is not such a whimsical idea, the other bigwigs must have thought of it, but why did Mu Jingchi bring it up? Because he has accepted the relevant knowledge of the future!

Whether it is phase diagram thermodynamics, or related mechanical properties, the use of tools in the math house to build material models will be more in-depth in the future, and Mu Jingchi will naturally be able to go further on this road with the help of future knowledge.

So, he brought it up.

"You can look at some of the phase diagrams that I have made, which are Gibbs free energy-component curves for each phase at different temperatures... ”

Mu Jingchi can be regarded as having gone through a lot of big scenes, so he will naturally not be frightened by this form of seminar, and he talks fluently, thinks clearly, and is reasonable.

When the Gibbs free energy-component curves of two phases do not intersect, it means that only a stable single phase exists at a certain temperature, and this stable phase is the phase with the lowest Gibbs free energy, which corresponds to the single phase region in the phase diagram.

If the Gibbs free energy-component curves of the two phases intersect, there must be a common tangent line, and the composition corresponding to the two tangent points represents the composition of the two equilibrium phases at this temperature. There are two phases on the phase diagram within this compositional range.

If a weak two-phase Gibbs free energy-component curve intersects, but only tangent at the intersection point, then the phase transition electricity corresponding to this tangent point in the phase diagram represents the equilibrium of the two phases of the same composition.

When there are three phases, such as three Gibbs free energy-component curves intersect in turn, there are two common tangent lines, there are two pairs of equilibrium phases, and the components corresponding to the tangent point represent the components of the equilibrium phase, such as the Gibbs free energy-composition curve of three phases only has one common tangent line, which represents the three-phase equilibrium.

The components corresponding to the three tangent points represent the components of the equilibrium phase of the three brothers, and there is a horizontal line of the coexistence of the three phases on the phase diagram.

Phase diagrams are as important to materials scientists as maps are to travelers, so if they are built perfectly, they can be of great use in materials research.

For example, what can be synthesized by mixing several compounds together, and how much of the predicted phase composition can be obtained in the end, such as the structural stability of the material under the use conditions, such as the composition design of the new material, the determination of the material preparation process, and so on.

Because of this, the other bigwigs also listened very carefully, as did Professor Gao and Professor Xu.

According to the phase diagrams established by the Gibbs free energy-composition curves of the liquid phase and the solid solution phase at different temperatures, the free enthalpy-composition curves and corresponding phase diagrams of the L phase and the solid solution α phase at T0, T1, T2, T3, T4, T5 and other temperatures are given. ”

Mu Jingchi was still talking, and the expression on his face revealed extraordinary confidence.

"In the case of the formation of a continuous solid solution in the above example, it can be regarded as an ideal solution, and its vapor pressure and composition are subject to Raoult's law. ”

"At T temperature, a solid solution of composition xs/b is in equilibrium with a liquid phase of composition of xl/b. ”

"In equilibrium, there is the following relationship: μl/a = μs/a; μl/b=μs/b.。 ”

"The chemical position of component A in the two phases can be expressed as, μl/a = G0l/a + RTlnxl/a; μs/a=G0s/a+RTlnxs/a。 ”

“。。。 ”

ln(Xsb/xlb=△Hma(Tb-T)/RTTb) can be exported. ”

“。。。 ”

Because of the limited time, Mu Jingchi came to the project team of nickel-based superalloys for too short a time, so he only did a beginning and did not participate in the more in-depth part.

But Mu Jingchi feels that just this beginning is worth studying in this direction.

It is not clear when the results will be produced, and whether the results are good or bad, but the research idea that Mu Jingchi came up with is an idea that integrates the tools of material thermodynamics and mathematical methods in the future, which is more forward-looking than the current idea and is worth investing in this direction.

"Dr. Mu, your plan... It's not too rigorous, is it?"

The first to speak was Professor Gao, whose words were actually very euphemistic, and the implication was actually a direct denial of his research direction.

"It is feasible to use computer simulation to simulate the microstructure of materials, but it is not enough to support the study based on this model, which is a bit less rigorous. ”

Mu Jingchi's gaze swept over the others, and the other bigwigs were either expressionless, or looked at their own research plans, and did not pay attention to Professor Gao's speech.

"There is a deviation in the model at the beginning, not to mention the subsequent phase diagram, and when it comes to more in-depth composition design and material technology, this bias is not good. ”

"And the thermodynamic calculations behind this, some equations and formulas that I don't understand very well, it seems that this is a mathematical tool proposed by yourself Dr. Mu?"

"I don't know if the application of these mathematical tools is correct and accurate. ”

"The most important thing is that, Dr. Mu, we have discussed your idea before, and we have also done relevant experiments. However, the experimental data is far from the theoretical data, and it cannot be used as a guide for material research and development. ”

Mu Jingchi's expression was a little serious, and he didn't say anything else to refute.

"I see, thank you Professor Gao for the rectification, I'll think about it again. ”

With that, he sat down and ended his speech.