EFFECT OF INITIAL GAMMA PRIME SIZE ON THE ELEVATED-TEMPERATURE CREEP-PROPERTIES OF SINGLE-CRYSTAL NICKEL-BASE SUPERALLOYS
EFFECT OF INITIAL GAMMA PRIME SIZE ON THE ELEVATED-TEMPERATURE CREEP-PROPERTIES OF SINGLE-CRYSTAL NICKEL-BASE SUPERALLOYS
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DOI：
10.1007/bf02647026
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发表时间：
1987-11-01
期刊：
影响因子：
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通讯作者：
NATHAL, MV
中科院分区：
文献类型：
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作者：
NATHAL, MV
研究了初始γ′尺寸和形状对两种单晶镍基高温合金高温蠕变性能的影响。选择这两种合金来代表不同程度的 γ-γ' 晶格失配。通过各种淬火和时效处理产生一系列初始微观结构。在 1000 °C 的蠕变断裂测试中，在蠕变寿命早期，γ' 定向粗化形成 γ-γ' 片层。两种合金都表现出作为初始 γ' 尺寸函数的抗蠕变性峰值。该峰对应于由沿[001]方向排列的立方形沉淀物组成的初始微观结构。这些排列整齐的立方体γ′颗粒在蠕变早期定向粗化成相对完美的片状γ-γ′结构，而在欠时效和过时效材料中形状和分布更不规则的γ′颗粒形成更不规则的片层，缺陷更多。失配程度较低的合金对初始γ'尺寸和形状不太敏感。
The influence of initial γ′ size and shape on the high temperature creep properties of two single crystal nickel-base superalloys was investigated. The two alloys were chosen to represent different magnitudes of γ-γ′ lattice mismatch. A range of initial microstructures was produced by various quenching and aging treatments. Creep-rupture testing at 1000 °C was performed under stresses where γ′ directionally coarsens to form γ-γ′ lamellae in the early portion of the creep life. Both alloys exhibited a peak in creep resistance as a function of initial γ′ size. The peak corresponded to an initial microstructure consisting of cuboidal precipitates aligned along [001] directions. These aligned cuboidal γ′ particles directionally coarsened into a relatively perfect lamellar γ-γ′ structure in the early stages of creep, whereas the more irregularly shaped and distributed γ′ particles in both under and overaged material formed more irregular lamellae with more imperfections. The alloy with a lower magnitude of mismatch was less sensitive to initial γ′size and shape.