Degradation of residual strength in SCS-6/Ti-15-3 Due to fully reversed fatigue

Abstract

Little attention has been given to residual strength degradation in titanium matrix composites (TMCs) after exposure to fatigue loading. To address this problem, fatigue tests on SCS-6/Ti-15-3 were performed to investigate the fatigue life and residual strength behavior of TMCs with different fiber volume fractions. Results indicate that fiber volume fraction seems to have an effect on both of these quantities. Lower fiber percentages result in a material where the characteristics of the matrix, such as hardening or cracking, play a much larger role in the composite response. Fatigue lives were not affected by fiber volume fraction at higher strain ranges, but lower fiber volume fractions resulted in shorter fatigue lives at lower strain values. Also, a slight increase in residual strength occurred up to 75 pct of fatigue life, for the lower-fiber volume fraction material. Despite these distinctions between specimens with different fiber contents, all specimens tested retained the majority of their strength prior to failure.

Damage accumulation during cyclic loading of a continuous alumina fibre reinforced aluminium composite

“…Fatigue mechanisms and properties in this system are now reasonably well understood and documented [1,[3][4][5][6][7]. Other systems that have been characterized in fatigue include composites of aluminium reinforced with glass [8], SiC [9], B [10], or first-generation alumina fibres [10][11][12][13].…”