Cyclic Deformation and Fatigue of Precipitate Hardened Single Crystals

摘要

A study has been made of precipitation hardened alloys because their fatigue properties can be improved by a much smaller factor than their monotonic strengths. The aim of the work has been to understand why the hardening precipitates are unstable to cyclic strain because this leads to cyclic softening in persistent slip bands (PSB's), strain localization and, therefore, fatigue failure at disappointingly low applied stresses. Both crack nucleation and propagation mechanisms are affected by such precipitate instability and PSB's.