Method for directly molding high-entropy alloy turbine engine hot end component through laser metal

[0052] Example 1

[0053] Five metals, W, Ti, Zr, V, and Ta, were selected and configured into high-entropy alloy powder according to the atomic ratio, and placed in the synchronous powder feeding equipment of the LMDF rapid prototyping equipment. The 3D CAD model of the hollow turbine blade is established by UG software and sliced ​​and layered, imported into Magics software to add auxiliary support structure, and the obtained stl format file is imported into the industrial computer. According to the vapor pressure of these five different elements, the laser power is selected as 200W. At the same time, due to the tiny air film holes and exhaust edge structure inside the hollow turbine blade, and the high requirements for the surface quality and forming accuracy of the formed parts, it is necessary to use small focal length of the lens (100mm) to obtain a fine focused spot size (30μm). A hybrid scanning path of contour + grating + partition was adopted, the scanning speed was set to 100 mm/s, and the scanning layer thickness Δh was 30 μm. A shielding gas (argon) was charged into the molding chamber to prevent oxidation of the high-entropy alloy powder. After adjusting the equipment, turn on the synchronous powder feeding equipment, turn on the laser, and start the laser rapid prototyping process. After continuous layer-by-layer additive manufacturing, a hollow turbine blade blank with an auxiliary support structure is obtained. Finally, the excess auxiliary support structure in the green body is removed by wire cutting process, and then the green body is subjected to abrasive flow finishing and surface sandblasting treatment, and finally a hollow turbine with dense structure, good forming accuracy and surface quality, and excellent high temperature mechanical properties is obtained. blade. like Figure 4 As shown, the blade basin 15, the trailing edge 16 and the blade back 17 have distinct shapes, compact structures, high forming precision, good surface quality, and excellent high temperature mechanical properties.

[0054] Example 2

[0055] Five metals, W, Ti, Zr, V, and Ta, were selected and configured into high-entropy alloy powders according to the same atomic ratio, and placed in the synchronous powder feeding equipment of the LMDF rapid prototyping equipment. The 3D CAD model of the turbine disk is established by UG software and sliced ​​and layered, and then imported into Magics software to add auxiliary support structure, and the obtained stl format file is imported into the industrial computer. According to the vapor pressure of these five different elements, the laser power is selected to be 200W. At the same time, due to the fine structure inside the turbine disk, and the high requirements for the surface quality and forming accuracy of the formed parts, a lens with a small focal length (100mm) is required to obtain fine The focused spot size (50 μm). A hybrid scanning path of contour + grating + partition was adopted, the scanning speed was set to 100 mm/s, and the scanning layer thickness Δh was 50 μm. A shielding gas (argon) was charged into the molding chamber to prevent oxidation of the high-entropy alloy powder. After adjusting the equipment, turn on the synchronous powder feeding equipment, turn on the laser, and start the laser rapid prototyping process. After continuous layer-by-layer additive manufacturing, a turbine disk blank with an auxiliary support structure is obtained. Finally, the excess auxiliary support structure in the green body is removed by wire cutting process, and then the green body is subjected to abrasive flow finishing and surface sandblasting treatment, and finally a turbine disk with dense structure, good forming accuracy and surface quality, and excellent high temperature mechanical properties is obtained. . like Figure 5 As shown, the outer ring 18 , the cold air holes 19 , the disc 20 and the guide vanes 21 have compact structures, good forming accuracy and surface quality, and excellent high-temperature mechanical properties.

[0056] Laser metal direct forming (LMDF) technology, as an advanced additive manufacturing technology, can use laser to directly form functional parts with almost any shape and complete metallurgical bonding. At the same time, the processed parts have high density and high Forming accuracy and surface quality. For high-entropy alloy powders composed of five or more refractory metals, the LMDF technology can be used to melt the metal powder by laser scanning to form a molten pool, and then solidify and accumulate through the molten pool. end parts, thus solving the problem that high-entropy alloys cannot obtain parts by traditional investment casting methods. Therefore, this method can fabricate high-entropy alloy turbine engine hot-end components with good high-temperature performance above 1600 °C.

[0057] To sum up, the high-entropy alloy prepared by using the high-melting point metal powder in the present invention needs to be investment cast at above 2000 ° C. The current ceramic casting cannot meet such a high temperature, and the LMDF technology can use the laser to convert the high-entropy alloy The powder melts rapidly to form a molten pool, and then solidifies and accumulates through the molten pool to realize the additive manufacturing of high melting point metals. The use of LMDF technology makes the present invention not limited by the complexity of the formed parts, without the need for support, the hot end parts of the turbine engine are directly formed, and the errors generated in the traditional investment casting core and shell assembly process are avoided. The invention utilizes the LMDF forming technology to realize the direct forming of the hot end components of the turbine engine, has simple manufacturing process, high forming speed, greatly improves the efficiency, and reduces the production cost at the same time.