Interpretation of the Habit Plane of δ Precipitates in Superalloy Inconel 718

• 来源期刊: 金属学报（英文版）
• 年，卷（期）: 2018,（2）
• 页码范围: 113-126
• 页数: 14页
• 语种: 英文

摘要

A calculation method based on a combination of △g parallelism rule,good matching site (GMS) analysis,CSL/DSCL (coincidence site lattice/displacement shift complete lattice) and the O-lattice theory has been applied to interpret the observation of the habit plane (HP) of the δ precipitates and the linear defects in the HP in an Inconel 718 superalloy.The small scattering in the HP orientation around an ideal rational plane is interpreted by the existence of a mixture of two types of steps with different heights and inclinations.These steps play a significant role to enhance the degree of matching in the HP.They are associated with secondary dislocations,with Burgers vectors of 1/6[1 1 (2)]γ/1/3[0 0 1]δ,and with a direction parallel to a near-invariant line along [1 (1) 0]γ.The spacing of the secondary dislocations projected on the terrace plane is around 6.3 nm.The calculated dislocation structure is in good agreement with the observation.