Abstract:

ESDU 90028 presents crack propagation rate curves derived from experimental data extracted from the literature for pure titanium and various titanium alloys in a variety of environments. The environments are vacuum, dry argon, air, distilled water and sodium chloride solution with some limited data for sodium bromide solution and an aqueous solution of methanol and hydrochloric acid. Graphs present the data for each material, heat treatment and environment, and allow the effects of stress ratio, loading frequency and grain orientation to be seen. The results are discussed in relation to those factors; in particular, the different behaviour seen with frequency variation depending on the environment is explained in terms of the effects of passivation (formation of a protective oxide film) and the onset of cyclic stress corrosion cracking. The alloys for which data are included are Ti-6Al-4V, Ti-8Al-1Mo-1V, Ti- 6Al-6V-2Sn and Ti-2.5Cu, and the commercially pure titanium was Ti-70 and IMI 130. Full details of the materials, specimens, test conditions and sources of the data are included, and the constants in the Paris crack growth equation are also given.