Chapter 578 Single crystal blade investment casting

Equipment testing is a very serious matter, and it is certainly not a one-time deal.

After several repeated experiments, a series of things such as data analysis and performance calibration will be involved.

Only after all the follow-up work has settled, can we truly be sure that the equipment has achieved the pre-designed specifications.

Therefore, when Chang Haonan received the news that the GPS jamming equipment test was a complete success, it was already three days later.

At this time, he had returned to Shengjing by special plane from Beijing and was planning the production of turbine disks and turbine blades at Liming Factory.

As a result, just after the opening part of a seminar, he was called out by the confidential secretary, saying that there was an internal call.

Then it took almost half an hour to come back.

"Mr. Chang, is there... a change in your plans?"

Zhong Shihong, who was sitting on the left side, came over and asked softly.

Although he has been promoted to deputy general manager of Liming Factory, Zhong Shihong is still personally responsible for the specific production work of the Taihang project.

As a business manager with a senior technician background, he knew that his administrative level and background were not enough. If he wanted to go further, he could only continue to stick to the technical route.

At the same time, I also hugged Mr. Chang’s thigh and held on.

Seeing Zhong Shihong looking worried that he might run away at any time, Chang Haonan burst into laughter:

"There is no change. It was just a small project. You just informed me of the results. Don't worry."

The former nodded understandingly and sat back down again.

But I don't agree with Chang Haonan's "small project" statement.

How can it be a trivial matter that can be asked by Mr. Chang in person during the mid-term meeting?

What a joke.

But in fact, Chang Haonan did not tell lies.

The scale of the GPS jammer project is not large.

He and Xu Yang were the only core designers, and from beginning to end, including the testing process, it only cost less than 50 yuan.

Although it took a long time, the actual work time was less than a month.

Originally, the most troublesome part should be the GPS navigation module inside.

As a result, the Self-Defense Forces sent warmth directly, or two at a time, with almost no effort.

In addition, because each jammer requires a complete set of military GPS positioning modules, mass production is basically impossible.

For Chang Haonan today, it is indeed a small job.

The reason why he had to ask in person was because it involved a matter that he needed to resolve.

It was a matter on his mind that he had been thinking about how to solve since his rebirth.

……

After a brief interlude, the technical seminar that had just been interrupted naturally resumed.

Chang Haonan is already familiar with this kind of scene.

However, this time the situation is special.

Sitting in the conference room with him were not only the Liming Factory technicians involved in the Taihang project, but also some of the engineers at the die forging press responsible for casting large-size parts of the movable beam.

After all, both parts of the job essentially rely on the same technology.

Investment casting.

In fact, before Chang Haonan actually entered the military industry system, when he was inspected at Beijing Hang University, he once proposed that numerical calculation methods can be used to conduct quantitative simulation evaluations of continuous or semi-continuous casting processes (

For now, the formation process of castings can only be speculated based on experience and preliminary theory. In actual casting, repeated trials and analysis are needed to determine the process plan.

The purpose of numerical simulation is to accurately obtain reasonable control parameters at each stage of casting molding, including the calculation of temperature field, flow field, stress field and concentration field. Reduce the number of tests, eliminate casting defects, and even conduct structural simulation to further control the performance of castings.

But this is still just an idea.

If it is really implemented, as a research object with multiple physical fields, changes in physical states, and the boundaries of the research system in the entire process flow are still in an unstable state, we cannot simply copy past experience.

Although TORCH Multiphysics is a well-founded platform, it still requires special optimization for the casting process before it can be used.

"Mr. Chang, we can understand what you mean, but how can we accurately express the entire filling and solidification process of investment casting in mathematical form?"

Fu Jiangwei, chief engineer from Zhaodu Casting Co., Ltd., asked first.

Zhaodu Casting was originally a state-owned enterprise affiliated to Zhaodu Iron and Steel Group. Later, during the process of economic restructuring, it was transferred to the chief engineer of the original factory in the form of a share-holding contract.

This privatization and restructuring was a win-win situation. Zhaodu Steel Group was able to travel lightly and concentrate on its core business. Zhaodu Casting also gradually grew and grew after getting rid of the restrictions of rules and regulations, and eventually became a first-class supplier for the die forging press project. the only private enterprise.

"This is not difficult."

Chang Haonan pulled the blackboard next to the conference room, picked up the chalk, and then turned back and asked:

"I would venture to ask, Mr. Fu should have some theoretical basis in mathematics, right?"

The reason for asking this is not because he has any prejudice. In fact, in this era, all walks of life are still in the stage where experience is king.

Especially in traditional fields like steel, many technicians come from wild backgrounds and have not received systematic higher education.

If this is the case, it may be difficult to understand what Chang Haonan says next.

"Yes, I am a graduate of Jizhou Mechanical and Electrical College in 80."

Fu Jiangwei nodded and picked up the ballpoint pen next to him——

The other party asked this, obviously wanting to show his strength.

“It is really not feasible to accurately calculate the entire investment casting process from a microscopic level.”

"But we can change our thinking and divide the research object into a continuous medium composed of infinite fluid microclusters in space, and do not study the movement and interaction of individual molecules during the casting process."

“Because the macroscopic behavior within a fluid is a spatially continuous function, analog research uses macroscopic continuous mathematical methods to study fluid motion.”

“For example, when molten metal flows into the mold cavity, the fluid model is relatively accurately described as an incompressible Newtonian fluid. Therefore, the mold filling process can be described by the mass equation, momentum equation and energy equation, while the solidification process can be described by Approximately a single heat conduction..."

Chang Haonan was dictating while writing furiously on the blackboard.

This part of the content may be relatively basic for some people who have done projects with him before, but there is still a certain threshold for others to understand.

"All the way here."

He said and pointed to the last equation on the blackboard:

"Up to this point, we can complete it with the tools we have on hand, but the later part, that is, the prediction of the shrinkage and loosening of the keyhole in the casting, needs to be adjusted based on your experience and some experimental results."

"To determine the specific state of the shrinkage keyhole, my current idea is based on the pressure loss of dendrites in the feeding channel during the solidification process."

Having said this, he filled in a new series of formulas below.

"That's the parameter design and calibration here."

Chang Haonan threw the chalk head back into the chalk box, then turned his seat and faced the people in front of him again:

“I plan to use two to three months to complete the model design of the entire investment casting filling and solidification process!”