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镍基单晶高温合金经充分均匀化、高温固溶和直接按时效处理后，沉淀出一种类树枝晶形态γ′相．类树枝晶γ′相的析出温度（Ｔ_（ｓγ′））敏感于局部合金成分，它的形核密度（Ｉ）与过冷度（△Ｔ_（γ′））成指数关系：Ｉ（μｍ~（－２））＝２．５×１０~（－３）ｅｘｐ（０，１１△Ｔ_（γ′））．在较小过冷度，类树枝晶γ′相尺寸与直接时效时间成正比．它的择优生长方向是〈１１０〉，与基体取向相同，完全共格．类树枝晶γ′的形核机制包括扩散和非扩散两种，并趋向对称形核．
Nickel-based single crystal superalloy fully homogenized, high temperature solution and direct aging treatment, the precipitation of a dendritic morphology γ ’phase. The precipitation temperature (T sγ ’) of the dendritic γ’ phase is sensitive to the composition of the local alloy and its nucleation density (I) is exponential with the degree of undercooling (△ T γ ’): I (-2)) = 2.5 × 10 -3 exp (0,11 △ T γ (γ ’)). At low degrees of supercooling, the dendritic γ ’phase size is directly proportional to the direct aging time. Its preferred growth direction is <110>, and the same orientation as the matrix, completely coherent. The nucleation mechanism of dendrites γ ’includes two kinds of diffusion and non-diffusion, and tends to nucleate symmetrically.