Multi-blade torque converter propellers and exhaust gas turbochargers are mainly made of aluminum alloy, so how to determine the formula of aluminum alloy and smelt the aluminum alloy suitable for these two aviation products has become the primary task of Dragon Soul Aircraft Manufacturing Company.

You know, in the early 30s, aluminum alloy was not widely used in the aviation industry, especially the propeller blades, which were basically made of wood. Metal propellers are almost impossible, and due to the complex shape of the propeller blades, the materials and processing techniques are difficult to use when using metal.

Even Maximime and David felt that this was simply an impossible task. Just kidding, to use aluminum alloy to make propellers, such aluminum alloy has not yet been developed in a factory.

Felix and Paul knew it would be difficult, but they also believed that Philip would not just develop such a product, and they also wanted to improve their level of competence and prove themselves by participating in the development of such a product.

Philip bought a batch of non-ferrous metal raw materials from Bofors, acquired a batch of rudimentary test equipment, and then began the research and development of aviation aluminum.

With his own memory, Philip wrote several recipes and gave them to Maximilian, putting him in charge of the experiment, assisted by David and three others.

When he received this task, Maximilian shook his head and said, "Mr. Philip, are you sure that these recipes can smelt the aluminum of propellers and turbochargers?" Now the whole world has not solved this problem, just a few of us, these rudimentary test equipment, is this possible? ”

Philip patted Maximilian on the shoulder and said, "Mr. Maximilien, I know that you have worked at BMW for many years, and you are the best material engineer in BMW, and you have in-depth research on engine materials and aluminum alloy materials. However, I am very confident in these formulas, why don't we make a bet, if you use these formulas to smelt the required aluminum, even if you lose, how about it? ”

Of course, Philip is confident, knowing that he is an ordnance expert in the 21st century, has participated in the research and development of a variety of weapons, and has a very deep understanding of metal materials and metal material processing. The formulas he came up with are aluminum alloy formulas that have been continuously optimized for decades. Among them, there is 2A11 aluminum alloy, which can be used as medium-strength structural parts of aircraft, propeller blades, transportation vehicles and building structural parts, medium-strength bolts and rivets of aircraft, etc. And 2024, which can be made into aircraft structures, rivets, missile components, truck wheels, propeller elements, and various other structural parts. 6061T6 aluminum alloy, which can make aircraft skin, fuselage frame, girder, rotors, propellers, fuel tanks, wall plates and landing gear struts.

Although I don't remember the composition and formula of these aluminum alloys too clearly, Philip still has an impression of what elements are roughly what they are, and how much they account for, as long as he does a few more tests, I believe he can find the best formula. For example, 6061T6 aluminum alloy is mixed with several other elements, such as copper, manganese, magnesium, zinc, chromium, titanium, silicon, and iron are indispensable, most of these elements are less than 1%, and elements like chromium and fierce are even less than 0.5%.

Maximilian hesitated, he thought to himself that maybe Philip's recipes would really succeed, so he quickly took a closer look at them. While he was watching, he also read: "6061T6 aluminum alloy has excellent processing performance, excellent welding characteristics and electroplating, good corrosion resistance, high toughness and no deformation after processing, dense material without defects and easy to polish, easy to color film, excellent oxidation effect and other excellent characteristics. Chemical composition: 0.20% copper, 0.15% manganese, 1.1% magnesium, 0.20% zinc, 0.15% chromium, 0.5% silicon, 0.7% iron. ”

Staring at these data, Maximilian thought for a moment, then looked at Philip suspiciously: "Mr. Philip, I don't know the propeller blades and turbine blades, what method are you going to use, casting or forging?" ”

Philip said in an affirmative tone: "Of course it is forged, the current casting technology simply does not meet the requirements, you must know that the turbocharger turbine is a high-precision part, the shape of the blades of the propeller is more complex, they have to bear a huge moment in the work, and only forging can eliminate the defects such as loose casting state generated by the metal in the smelting process, optimize the microstructure, and at the same time, due to the preservation of the complete metal streamline, the mechanical properties of the forging are generally better than the castings of the same material." ”

Maximilian nodded, "Well, but why do you add chromium and manganese to these recipes?" ”

Philip laughs: "These two elements are added to improve the hardness and corrosion resistance of aluminum alloy materials. Manganese has a very strange and interesting temperament, and if too much manganese is added to aluminum, the resulting aluminium is simply brittle like glass and crumbles when you knock it. However, if a small amount of manganese is added, it becomes both hard and tough. Both the ductility and strength of aluminum are improved. The addition of chromium can make aluminum resistant to corrosion, wear, high temperature and oxidation, and is also a useful metal element for turbine blades and propeller blades. ”

Maximilian thought for a moment and said, "Forget it, I won't bet with you!" Mr. Philip, I think you are right, these formulas are really beyond my imagination, although I have been working as a materials engineer for more than ten years, my level in aluminum alloys is far from yours. I took the task, and I promised to do it well and try to complete all the tests within a month. ”

Philip was also pleased to see Maximime's change of attitude, he looked at the other three, and said, "Please! The development of these aluminum alloy materials is related to whether qualified torque converter propellers and turbochargers can be developed. Although more than ten years ago, aluminum alloy was used in aircraft manufacturing, but it has never broken through the technical barriers of propeller and turbine manufacturing, and now aluminum alloy has been widely used in various fields, the production of primary aluminum has also begun to soar, and the price of aluminum has also been rapidly reduced, which is the time to apply it more widely to the aviation industry. ”

The four engineers from BMW looked at each other, then all nodded in agreement.

David took the paper with the recipe written on it from Maximilian's hand and looked through it with Felix and Paul.

Paul looked up and said in surprise, "This is the most complex formula I've ever seen, but I think if it succeeds, it will be a very good aerospace material." Aluminum is a metal with low strength and good plasticity, and the purpose of alloying is to improve the strength first, which is fully reflected by adding elements such as manganese and titanium. The addition of chromium improves the corrosion resistance of the alloy. The addition of magnesium greatly improves the tensile strength of aluminum alloy, and the content of about 1% is just right. ”