Fatigue of Dispersion Strengthened Ni with Ion Beam ModifiedSurface Layers

离子束改性表面层弥散强化镍的疲劳

• 批准号: 8707774
• 负责人: David Grummon
• 金额: $ 3万
• 依托单位: Michigan State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1987
• 资助国家: 美国
• 起止时间: 1987-10-01 至 1989-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8707774&HistoricalAwards=false
• 关键词: Fatigue; Dispersion; Strengthened; Ni; Ion

This project deals with the study of surface damage accumulation during fatigue of oxide dispersion strengthened nickel which has been surface modified by ion beam mixing of aluminum. The work is intended to advance the understanding of the mechanisms by which novel surface modifications can influence cyclic deformation phenomena associated with fatigue crack initiation and thus prolong fatigue life. Results will be compared with those recently obtained in a study of pure nickel with similar surface modifications in which it was found that the behavior of the surface layer was controlled mainly by bulk plastic strain localization events. The research will focus on an alloy which is chemically similar to pure nickel (since the dispersoid phase is inert), but which will display different behavior with respect to slip band extrusion, cyclic hardening, and plastic strain localization behavior. Specimens will be prepared using an established technique of vacuum evaporation of multiple layers of Ni and Al followed by high energy inert ion irradiation, resulting in a supersaturated solid solution of Al in Ni in a surface layer about 100 nm thick. These will be subjected to plastic strain controlled fatigue while monitoring the accumulation of surface damage by scanning electron microscopy and optical interferometry. Slip homogeneity and the spatial distribution and the detailed local morphology of slip bands features will be analyzed and compared to the behavior of unmodified nickel in both the pure and dispersion strengthened forms.

本项目研究的是地表损伤累积过程， 氧化物弥散强化镍的疲劳性能 通过铝的离子束混合改性。 这项工作旨在 促进对新表面的机制的理解， 修改可以影响与以下相关的循环变形现象： 疲劳裂纹萌生，从而延长疲劳寿命。 结果将 与最近在纯镍的研究中获得的结果相比， 类似的表面改性，其中发现， 表层主要受体塑性应变控制 本地化事件。 该研究将重点关注一种合金， 化学上类似于纯镍（因为弥散相是惰性的）， 但是其相对于滑动带将显示不同的行为 挤压、循环硬化和塑性应变局部化行为。 将使用既定的真空技术制备样本 蒸发多层Ni和Al，然后用高能量 惰性离子辐照，导致过饱和固溶体， Al在Ni中的表面层约100 nm厚。 这些将受到 塑性应变控制疲劳，同时监测积累 表面损伤的扫描电子显微镜和光学 干涉测量法 滑动均匀性和空间分布以及 将分析滑移带特征的详细局部形态， 与未改性的镍在纯镍和 分散强化型。