Abstract
Micro-mechanisms of crack-tip shielding associated with the growth of fatigue cracks in metalmatrix composites are examined with specific emphasis on the role of crack bridging by uncracked ligaments. Simple analytical models are developed for such bridging induced by both overlapping cracks and by coplanar ligaments in the wake of the crack tip; the models are based on respective notions of a critical tensile strain or critical crack-opening displacement in the ligament. The predicted degree of shielding derived from these mechanisms is not large, but is found to be consistent with experimental observations in high-strength P/M aluminum alloys reinforced with 15 to 20 vol pct of SiC particulate.
| Original language | English |
|---|---|
| Pages (from-to) | 897-908 |
| Journal | Metallurgical Transactions A |
| Volume | 20 |
| Issue number | 5 |
| DOIs | |
| Publication status | Published - May 1989 |
| Externally published | Yes |