Relations between Microstructure and Fatigue Properties of Alpha-Beta Titanium Alloys

摘要

A wide variety of microstructures can be produced in alpha-beta titanium alloys by suitable choices of composition, processing and heat treatment. The dependence of mechanical properties on micro-structure in these alloys, and the metallurgical factors necessary and responsible for preparation of particular microstructures, are fairly well understood. This brief review summarizes those factors, with an emphasis on fatigue properties, including the basis for recommendations on microstructural modifications which can improve or optimize fatigue resistance. These recommendations can be separated into either the high-cycle or "S-N" regime in which crack initiation dominates, or the low-cycle or "da/dN-ΔK" regime in which crack propagation is the primary property. Schematic microstructural models are discussed for both monotonic and fatigue properties.