The laboratory of the School of Mechanical Engineering is larger than that of the School of Materials, because there are more mechanical equipment in it than that of the School of Materials, so the design of the laboratory is also broader.

Mu Jingchi should be the last big guy to arrive, when he came to the laboratory under Ai Xiaosheng's guidance, many big guys were already in the lab.

The machinery and equipment continue to operate, new metal sheets are processed, and the bigwigs are testing around the metal sheets.

"Aren't you coming home, why are you so late?"

Yang Wenwu was the first to notice Mu Jingchi's arrival and asked casually.

"I went shopping with my girlfriend, and I was stuck in a traffic jam on the way back, so I came a little late. Mu Jingchi looked at the crowd around him, and actually found Director Hao of the military, Gao Mingsong and Professor Xu Shiquan.

I guess when they didn't leave, they happened to encounter something from the School of Mechanical Engineering.

"What are the test results now?"

There is not much politeness, everyone is a member of the research group, and there are a lot of contacts, basically acquaintances, Mu Jingchi also went straight to the core and asked.

"Professor Dong, Professor Dong?"

Yang Wenwu did not answer Mu Jingchi directly, but took Mu Jingchi into the crowd, and saw Professor Dong Xinren, who was explaining to the leaders of Huaqing University, the Ministry of Industry and Information Technology, and the Ministry of Science and Technology.

"Dr. Mu, you're here!" Dong Xinren heard Professor Yang Wenwu's shout, turned his head and saw Mu Jingchi, with a smile on his face, and hurriedly greeted Mu Jingchi with joy.

"Looks like the result is pretty good!"

Mu Jingchi first said hello to the leaders, and when he saw Professor Dong's expression, he knew that it should be a good result.

There are so many big guys, if the result is not good, it will be quarreled a long time ago.

"Yes, we have found the correct method!" Professor Dong Xinren's face was full of red light, his expression was radiant, and his eyes couldn't hide his excitement, "It's still thanks to Dr. Mu's dislocation theory!"

Between the words, Dong Xinren also had a sense of gratitude.

The dislocation theory has made theoretical achievements, and the transformation of theory into practice and the transfer of the project to the School of Mechanical Engineering is actually a debt to the School of Materials and Mu Jingchi.

In China, I don't know how many research teams can do this project that translates theory into practice, but it falls on their School of Mechanical Engineering.

There are people in it.

"To what extent?" Mu Jingchi didn't think about it so much, he attached more importance to the research results, and continued to ask.

"What we mainly do is the plastic deformation of metals, the plastic deformation of monocrystals, polycrystals and alloys. When it comes to scientific research, Dong Trust also reports to Mu Jingchi seriously.

"According to the dislocation theory, we have carried out more refined and precise improvement control of the plastic processing method, and we have been able to restrain the movement of some dislocations, so as to enhance the mechanical properties of the material. ”

There are two types of plastic deformation of single crystals: slip and twin. The movement of the dislocation causes slippage, which is to restrain the movement of the dislocation, and also change and improve the properties of the material.

The vast majority of metals used in engineering are polycrystalline. Each grain in a polycrystalline is deformed in the same way as a single crystal. However, due to the different grain orientations and the presence of many grain boundaries in polycrystalline materials, the deformation is much more complex.

In polycrystals, the irregular arrangement of atoms on the grain boundaries hinders the movement of dislocations and increases the deformation resistance. The finer the metal grains, the more grain boundaries, and the greater the deformation resistance, the greater the strength of the metal.

In the case of slip, the soft dislocation starts towards the grain, and when the dislocation is blocked at the grain boundary and gradually accumulates, the other grains slip. Constraint dislocation and guide dislocation indirectly affect the grain.

When polycrystals are deformed, the grains are deformed in batches and gradually, and the deformations are scattered throughout the material. The finer the grain, the more dispersed the deformation of the metal, which reduces the stress concentration, delays the formation and development of cracks, and makes the metal have a large plastic deformation before fracture, so that the plasticity of the metal is improved.

As for the plastic deformation of alloys, they are divided into two categories.

When the composition of the alloy is a solid solution, the solute atoms will cause lattice distortion, increase the slip resistance, and produce solid solution strengthening, and the solute atoms are often distributed near the dislocation, which reduces the lattice distortion near the dislocation, reduces the dislocation mobility, increases the deformation resistance, and increases the strength.

When the structure of an alloy consists of a solid solution and a diffusely distributed metal compound, the second-phase silver dots act as an obstacle to the dislocation movement. Under the action of external force, the dislocation line bends when it encounters the second phase particle, and a dislocation ring is left around the second phase particle after the dislocation passes.

The presence of hard points in the second phase increases the resistance of dislocation movement, which increases the slip resistance, thereby improving the strength of the alloy.

Of course, it's not as simple as it sounds.

"We have found that this plastic processing method has universal applicability to metal materials, and the current effect is not very obvious, according to our tests, it can only improve the mechanical properties by 20%. ”

"However, with future research, we are confident that we can achieve a 40% improvement in mechanical properties. ”

Mu Jingchi's face naturally jumped up with joy, and said it through Dong Renxin's mouth, which was basically accurate.

"Thank you for your hard work. ”

In terms of material processing, Mu Jingchi does not know much about it, and he is now better at materials science and material physics and chemistry.

But he also knows how difficult it is to improve material properties through material processing, even if it is based on dislocation theory. This involves the yield and deformation resistance of metals, the thermodynamic conditions of metal plastic deformation, the changes in metal plastic deformation and microstructure properties, the plasticity and fracture of metals, and other plastic processing metallurgy.

There are also metal plastic processing mechanics that involve the stress-strain state and the stress-strain distribution law in the deformed body, the determination of the physical and mechanical equations of the deformed materials, and the establishment of the analysis and calculation methods of the deformation and mechanical energy parameters according to the basic equations of deformation mechanics and the characteristics of the plastic processing deformation process, so as to provide a basis for the correct selection of plastic processing deformation methods, the formulation of reasonable process regulations, the optimization of the design of tools, molds and processing equipment, and the analysis and resolution of product defects.

"However, in terms of subsequent heat treatment, we have no good way, and we can only process according to the existing heat treatment process. ”

Dong Xinren looked at Mu Jingchi, his eyes revealed hope, as if he desperately hoped that Mu Jingchi would give them a direction again.

"In terms of heat treatment, I can't do anything for the time being, so I can only wait for the follow-up theoretical breakthrough, and after the theoretical breakthrough, it should be able to guide the improvement of the heat treatment process. ”

Mu Jingchi shook his head, he didn't know when he would be able to break through the follow-up recovery and crystallization dislocation theory.

"Then let's continue to dig deeper into the plastic processing aspect!" Dong Xinren said, without much frustration on his face.