Sidnikam was appointed chief designer of the Dragon Soul aircraft manufacturing company, and Antonov was appointed assistant to the chief designer.

Both Sidnikam and Antonov had a fanatical interest in the all-metal multi-blade torque shift propeller, a groundbreaking design no less than the invention of the all-metal monoplane! In particular, I heard that this kind of propeller can more than double the aerodynamic efficiency of the aircraft power system, and the eyes of the two designers from different countries began to glow. It's unimaginable.

In addition, the exhaust gas turbocharger is also a product that has a huge effect on the performance improvement of aircraft engines, and Cam has also learned about it in the British Hawker Company, and several companies in the United Kingdom are developing this product, but it has been stuck in the threshold of materials and processes, and has not been successfully developed. And the Americans, although they claimed to have developed it, did not install their turbochargers on mass-produced aircraft, and Cam even doubted whether the Americans' turbochargers were really practical, otherwise they would not have been able to sell such products to Europe.

Because these two products use high-performance aluminum alloy, and there are no aluminum alloy products suitable for metal torque conversion propeller blades and turbine blades in the world, and the smelting process of aluminum alloy for forging is not mature enough, so that the aluminum alloy material produced is either too soft or too brittle, or mixed with a large number of sand hole bubbles, and a large number of cracks appear once forged, and cannot be manufactured into blades at all.

On the third day of Philip's appointment of Cam as the chief designer, the 2A11 aluminum alloy formula was finally successfully smelted!

Philip's recipe was only made a few minor adjustments, and Maximi and the others quickly found the best way to calculate the ingredients, such as the magnesium in the recipe, which is easily burned out in the melting, so the upper limit must be taken when calculating the ingredients. Moreover, in the smelting, the order of charging is also very important, which material is added first and which material is added later, which has an impact on the melting of aluminum alloy. The control of furnace temperature is even more important, and the choice of flux cannot be ignored. Fortunately, Philip's recipe has been tried and tested by countless scientific and technological workers in later generations, and although some of the ingredients are not exactly the same, they are still very successful.

When Philip heard Anna tell him the good news, he couldn't help but stride to the laboratory. I saw several people in the laboratory gathered on the test bench, including the company's deputy general manager Lucas, chief designer Sidnikam, assistant to the chief designer Antonov, as well as Maximilien, David, Paul and Felix.

Philip walked directly to the test bench, grabbed a few aluminum alloy plates and took a closer look, and said happily: "Not bad, not bad!" These test products are very good in appearance, there are no obvious defects on the surface, there are very few shrinkage holes, sand holes, porosity and slag inclusions, if you can use die-casting technology, the quality of these aluminum plates should be able to go to a higher level! ”

Antonov asked puzzledly: "Mr. Philip, I don't know much about the manufacturing process of aluminum alloy, what kind of technology is the die-casting technology you are talking about?" ”

Philip looked at everyone, and saw that they were also expectant, so he nodded and said slowly: "Everyone knows that the chemical properties of aluminum are very lively, and it is easy to react with water during the smelting process to oxidize and absorb hydrogen. The saturation solubility of hydrogen in aluminum alloy varies greatly from liquid to solid, which makes it easy to produce defects such as pinholes and inclusions in aluminum alloy castings, and the quality and performance of aluminum alloy castings and forgings can be improved by removing the gas and inclusions in the aluminum alloy liquid and improving the melt quality. For example, the use of extrusion method, or semi-solid die-casting method, can greatly improve the quality of aluminum alloy materials. ”

"For example, the semi-solid die-casting method is to stir the liquid aluminum alloy when it solidifies, obtain a slurry with 50% or even higher phase composition at a certain cooling rate, and then use this paddle material for die-casting. It involves feeding an aluminum alloy liquid into a specially designed injection molding barrel, cooling it into a semi-solid slurry by applying shear using a screw device, and then die-casting. Philip put down the aluminum plate in his hand and said.

Maximi added: "Yes, semi-solid die-casting can indeed make the shrinkage of aluminum alloy smaller, and the slurry has better fluidity, which is convenient for shrinkage; And it is relatively easy to manufacture non-porous materials, its pouring temperature is low, and it can also be heat treated and welded, which improves the mechanical properties, which is very suitable as a forging material, and it is a good material for forging propeller blades! ”

Philip sighed: "Now we can start to buy forging equipment, forging aluminum alloy paddle is also a very complex process, because the paddle is a ternary complex surface shape, and the processing accuracy requirements are relatively high, in the forging process can not destroy the mechanical properties of aluminum alloy materials." Finally, the propeller blades are finished after a series of surface treatments. ”

Anna didn't know when she arrived at the laboratory, and when she heard Philip say this, she frowned and said, "Ah, this little propeller blade is so complicated to make!" I thought it would be over if I twisted it into that shape! ”

Philip laughed and said, "Anna, the metal propeller is so complex that few companies have succeeded in making it yet. If it is a wooden propeller, it is very simple, a wooden propeller is made of several layers of birch wood with the same thickness and the same form bonded together with waterproof resin, and then roughed and finely processed into a blade with a precise airfoil shape and pitch size. Wood is easy to process, while aluminum alloy is different, aluminum alloy propellers are characterized by high structural strength, thin and light blades, which can guide more air flow through the engine so that the engine can be better cooled, less maintenance work, low cost of use and maintenance, etc. But again, the manufacturing process is much more complicated. ”

Lucas also asked curiously: "Philip, how do you process this aluminum alloy propeller to meet the requirements?" ”

Philip explains with a smile: "The aluminium propeller is forged from a single piece of duralumin. Then through machining and manual grinding to obtain a satisfactory airfoil, by slightly twisting the blade, to obtain a satisfactory blade angle. Finally, it has to go through a series of chemical treatments to obtain a paddle that meets the requirements of use. The torque control device is more complicated, the propeller becomes larger and smaller, and the adjustment is generally carried out by the liquid pressure, and the resistance torque of the propeller is changed by changing the blade angle, so as to achieve the purpose of speed adjustment. ”

In the next few days, the rest of the aluminum alloys were also successfully trial-produced one by one. At the same time, Philip also purchased a number of mechanical processing equipment used in the aviation industry, because the trial production of metal torque converter propellers was about to begin, and only when the problem of multi-blade torque conversion propellers was solved could this advanced 6-blade or 8-blade propeller be used in the design of large transport aircraft.