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多晶的铸造镍基高温合金,尽管采用了固溶强化、γ′相质点沉淀强化和碳化物晶界强化等途径来提高合金的强度,但在高温下,由于合金的晶界强度低于晶内强度,因此常常在晶界处首先形成裂纹并导致断裂。定向凝固技术能使晶体按〈001〉方向顺序生长,得到的柱晶组织基本不含横向晶界,因而大幅度地提高了合金的各项纵向力学性能。用定向凝固技术,并通过螺旋选择
The polycrystalline cast Ni-base superalloy, although using the solid solution strengthening, γ ’phase particle precipitation strengthening and carbide grain boundary strengthening ways to improve the strength of the alloy, but at high temperature, the grain boundary strength of the alloy is lower than the crystal Internal strength, cracks are often first formed at grain boundaries and lead to rupture. Directional solidification technology can make the crystal grow in the order of <001> direction, and the obtained columnar structure basically does not contain transverse grain boundaries, thus greatly improving the longitudinal mechanical properties of the alloy. Using directional solidification techniques, and through spiral selection