A cylindrical steel specimen with a length of 120 mm and a diameter of 5 mm is suspended horizontally on two metal filaments, the two ends of which are connected to the excitation stage and pickup stage of the crystal transducer, and then the signal generator, signal amplifier, oscilloscope, frequency meter and other test equipment are outside.

Lin Fanghua and her sister He Xiaoyu stood in front of the test bench, meticulously debugging before the test. Lin Fanghua's eyes were bloodshot, her face was full of tiredness, and if you looked closely, you could see that her hands were trembling slightly, which was caused by fatigue after a long and continuous work.

What they're doing is testing the vibration damping properties of metal materials. This test method is called the bending resonance method, and its principle is to first generate a vibration signal with the same frequency as the natural vibration of the specimen by the signal generator to stimulate the resonance of the specimen. Then the vibration source is turned off and the free attenuation curve of the specimen amplitude is recorded. The faster the amplitude of the specimen decays, the stronger the internal friction of the material, and the better its vibration damping performance.

Finding a steel with good vibration damping properties was a key part of the project to develop an industrial steam turbine for ethylene compressor drives. The blades of industrial steam turbines have to withstand long-term, high-speed operation, and the vibration damping performance of the blade material is an important factor affecting the service life of the blade. If the vibration damping performance of the blade is poor, it is easy to experience high-frequency vibration during operation, resulting in excessive noise of the turbine, and the blade is also prone to fracture due to fatigue.

The research on leaf materials was undertaken by Professor An Zixuan of Huaqing University, and Lin Fanghua was An Zixuan's assistant, responsible for retrieving data and conducting post-material testing. According to An Zixuan's original estimate, it would take them about a year to complete all the work and come up with a steel that meets the requirements for vibration damping performance. But after learning the news of Lin Zhenhua's suspension, Lin Fanghua took the initiative to ask for help, threatening to come up with applicable materials within three months.

There is a reason why Lin Fanghua is so ruthless, she knows that she can't help her brother in social relations or politics, and the only thing she can do is to use her own skills to help her brother. Big ethylene is a project led by Lin Zhenhua, and if this project fails, those who pour dirty water on Lin Zhenhua will have more to say. On the contrary, if this project is successful, Lin Zhenhua will become a hero who leads independent innovation, and all those who want to attack him will have to re-weigh his weight in the eyes of the central leadership.

Since then, Lin Fanghua has moved his bedding roll to the data room, and the data clerks in the data room know that she is Lin Zhenhua's sister, so it is naturally difficult to stop her. Lin Fanghua bought four large steamed buns from the canteen every morning as food for the day, and then stopped going out, burying his head in the reference room to look through the dusty Soviet materials.

No one knew how many hours Lin Fanghua slept every day in those days, and the information staff only knew that she almost drank coffee as plain water, which made her nerves always in a state of high euphoria.

In just one and a half months, Lin Fanghua digested tons of Soviet experimental data and mastered the Soviet Union's experience in developing vibration-absorbing materials. Combined with the knowledge he learned during his study in the United States, Lin Fanghua proposed the development idea of vibration damping alloy materials.

It is not enough to have ideas, and the vibration damping performance of the damping alloy still needs to be verified by experiments. Lin Fanghua made a long list of experiments, asking the steelmaking plant to produce various samples according to different formulations and different heat treatment processes, and then tested them in the laboratory one by one.

An Zixuan sent several assistants to Lin Fanghua, who were doctoral and master's students from Huaqing University. These assistants can help Lin Fanghua do the testing of materials, but for the analysis of experimental data, Lin Fanghua needs to complete it himself. Based on the test results of each formula, she revised her theory and came up with a new formula. This is a very complex process, which tests the level of the analyst's understanding and the degree of data accumulation.

Again, no one remembered how long Lin Fanghua had been in the lab, only that the drawing paper that recorded the results of the experiment had been piled up in several filing cabinets. Zhang Yihua, who is responsible for the overall design of the industrial steam turbine, has been here several times, and when he sees the results of the experiment, he can't help but be overjoyed, because several materials taken out by Lin Fanghua have reached the domestic advanced level and meet the requirements he proposed. Lin Fanghua did not stop there, she had read in the literature that a laboratory in the United States had developed a vibration damping alloy called silentalloy, whose vibration damping performance is among the best among the various alloy materials currently known. Lin Fanghua's goal is to create a better material than silentalloy, so that the performance of Hanhua's industrial steam turbine blades can reach the world-class level.

"Xiao Yu, are you ready?"

"Senior sister, you're ready."

"Let's get started."

"Okay."

The signal generator was turned on, and He Xiaoyu skillfully adjusted the knob of the generator, so that the signal generator produced signals of different frequencies. The specimen initially vibrates slightly, and all of a sudden, the vibration becomes intense, indicating that the current vibration frequency coincides with the natural vibration frequency of the specimen, and the specimen has a co-frequency resonance.

"Turn off the vibration source and start recording the amplitude attenuation." Lin Fanghua ordered.

An oscillating curve appears on the screen of a ray recording oscilloscope, shaped like a fountain nib with a wide head, and then rapidly shrinks to almost a straight line. This rapidly shrinking shape indicates that the material has a very high internal resistance, which is precisely the material characteristic that Lin Fanghua strives for.

He Xiaoyu took out a pen to record the time when the amplitude decayed by half, and then substituted it into the formula to start calculating the internal friction value of the material. After clicking the calculator for a while, she waved the scratch paper excitedly and shouted: "Senior sister, it's successful, it's successful!" The internal friction value of our specimen is 20% higher than that of SilentAlloy! ”

"It worked, it finally worked." Lin Fanghua only felt a burst of ecstasy in his heart. In fact, this result was expected by her, she got inspiration from the experimental records of the Soviets, and after hundreds of previous experiments, there is no suspense at all to get today's result. Rao is like this, when she heard the data reported by He Xiaoyu, she still felt a kind of happy dizziness, she held back her excitement, and wrote on the experimental record:

"Sample formula: chromium 13%, aluminum 3%, nickel less than 0.6%, iron as the margin, high temperature annealing treatment, furnace cooling method, 1000 degrees Celsius 2 hours slow cooling ......"

After registering all the experimental data, Lin Fanghua signed his name at the end, and then said to He Xiaoyu: "Xiaoyu, send this experimental record to Zhang Gong immediately, he is waiting for our materials." ”

"No problem, senior sister!" He Xiaoyu continued to record the experiment and rushed out of the laboratory like a cheerful bird.

Lin Fanghua raised her head, wiped the sweat oozing from her forehead, stood up forcefully, and slowly walked out of the laboratory. When she walked outside the door, she only felt that the sun outside was so dazzling, she couldn't remember how long it had been since she had seen it.

Brother, did you see it, I finally did it, in three months, I took out the world's first-class vibration damping material!

Lin Fanghua shouted loudly in her heart, and then she felt that it was dark in front of her and fell to the ground.

……

Lin Zhenhua received the news when he was talking to Chen Tian, he jumped into the jeep given to him by Chen Tian like crazy, and rushed all the way to the hospital where Lin Fanghua was staying. When he rushed into Lin Fanghua's hospital room, he saw Yang Xin and Ma Jie sitting on both sides of the hospital bed, and it was Lin Fanghua who was pale lying on the hospital bed.

"Xiaofang, what's wrong with you?" Lin Zhenhua threw himself in front of the hospital bed, took his sister's hand and asked.

"Brother, I'm fine." Lin Fanghua had already woken up at this time, and when she saw her brother coming, she forced out a smile and replied weakly, "The doctor said that I may be a little anemic, and I fell if I didn't stand up well all of a sudden." ”

"Anemia? How can you be anemic! Lin Zhenhua asked loudly. Only then did he realize that his younger sister, who used to be chubby, was now so emaciated that it was distressing, there was hardly a trace of blood on her face, and the two simple little wine vortexes were gone.

"Yang Xin, what's going on?" didn't hear Lin Fanghua's answer, Lin Zhenhua turned his head to Yang Xin and asked.

"Xiaohua, I, I ......" Yang Xin stumbled a few words, and tears flowed down, "Xiaohua, I'm sorry, I'm sorry...... I didn't take good care of Xiaofang. ”

"It's not Yang Xin's fault." Lin Fanghua said, "Yang Xin often brings me food, but I don't eat well. Also, it may be that you have stayed up a lot of late and are a little tired. ”

"Can't eat well? Why don't you eat properly? Lin Zhenhua was full of wonder, he didn't know what Lin Fanghua was doing in the institute, although Yang Xin had told him about Lin Fanghua's hard work, he never imagined that Lin Fanghua would survive to this extent. "Xiaohua, Xiaofang has only slept three or four hours a day in order to engage in vibration damping materials in the past few months, and often forgets to eat. It's all my fault, I wish I hadn't let her do it sooner. It's all my fault, it's all my ......," Yang Xin cried and said to Lin Zhenhua. She and Lin Fanghua are close friends in the boudoir, and at the same time Lin Fanghua's sister-in-law, under her nose, Lin Fanghua was so tired that she was sick and hospitalized, and she felt that she was to blame.

Lin Fanghua saw Yang Xin crying sadly, and hurriedly excused her: "Yang Xin, how can I blame you? When I was studying in the United States, I did this a lot, and I got used to it. ”

Speaking of this, she turned her head to Lin Zhenhua and said: "Brother, let me tell you a good news, I have already made the vibration damping material that Zhang Gong wanted, which is better than Silentalloy in the United States, and is the world's first-class." Brother, are you happy? ”

Lin Zhenhua understood it all at once, his eyes were also a little moist, he sat on the edge of Lin Fanghua's bed, stretched out his hand, stroked his sister's hair, and complained softly: "Xiaofang, who let you mess around like this?" What world-class material, in my heart, is as important as your body? I only have one sister, you know? ”

Lin Fanghua leaned his head on his brother's arm, smiled and said: "Brother, I only have you as an elder brother, for so many years, you have always taken care of me, finally I can help you do something, no matter how hard and tired I am, I am willing." ”

"You're really my silly sister!" Lin Zhenhua's tears finally flowed down. Since his suspension, many people have cared for him and helped him, and all these friendships have touched him very much, but he has never shed a tear. At this moment, he shed tears, for this true love that blood is thicker than water.

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