凝固界面形态对一种镍基单晶高温合金组织和性能的影响

 以平界面凝固的一种镍基单晶高温合金组织不含有γ/γ′共晶;而以脆状、粗枝以及细枝界面凝固组织中,γ/γ′含量渐次增多。随着凝固界面形态的转变,γ′尺寸越来越小,形状越来越规则。细枝界面凝固的单晶具有最高的持久寿命,粗枝次之,而脆状界面凝固的单晶具有最短的持久寿命。

THE INFLUENCE OF SOLID-LIQUID INTERFACE MORPHOLOGIES ON THE MICROSTRUCTURE AND MECHANICAL PROPERTIES OF A NICKEL-BASE SINGLE CRYSTAL SUPERALLOY

This paper presents the study of the influence of the solid-liquid interface morphologies on the as-cast microstructure and mechanical properties of a single crystal nickel-base superalloy. The results show that there is no γ/γ' eutectic in the sample solidified with planar solid-liquid interface morphology. When the solid-liquid interface morphology is turned into celluar, then coarse dendritic, and finally fine dendritic ones, the amount of γ/γ' eutectic becomes more and more, the size of γ' smaller and smaller, and the shape of Y' more and more regular. The sample solidified with fine dendritic solid-liquid interface morphology has the longest rupture life, the sample with coarse dendritic solid-liquid interface morphology has has second longest rupture life, and the celluar structure has the shortest rupture life.