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选用20%CoO和80%Al_2O_3配成的CoO孕育剂,对铸造镍基高温合金涡轮叶片,是一种有效的孕育剂。CoO和Al_2O_3粉末混匀,在1300℃下煅烧2h后,成为在α-Al_2O_3颗粒表面上沉积蓝色CoO·Al_2O_3尖晶石层。浇铸过程中,铸造镍基高温合金中如C,Cr,V,Ti,Al等活泼元素还原CoO,生成面心立方晶系的金属Co.因其结晶结构和晶格常数与基体高温合金相近,就能促进叶片表面晶粒细化。在生产实践中,应该避免生成SiO_2的“白霜”,并注意合理降低浇铸温度和提高模壳焙烧温度。
The CoO inoculant made of 20% CoO and 80% Al 2 O 3 is an effective inoculant for casting nickel-based superalloy turbine blades. CoO and Al 2 O 3 powders were mixed and calcined at 1300 ℃ for 2h to form a blue CoO · Al 2 O 3 spinel layer on the surface of α-Al 2 O 3 particles. Casting process, the casting of nickel-based superalloy such as C, Cr, V, Ti, Al and other living elements to reduce CoO, generating a face-centered cubic metal Co. Because of its crystal structure and lattice constants similar to the matrix superalloy, Can promote the leaf surface grain refinement. In the production practice, should avoid the generation of “white frost” SiO 2, and pay attention to a reasonable reduction in casting temperature and increase the mold shell calcination temperature.