Comparison of sternal intramedullary bleeding prevention strategies in cardiac surgery

The effect of different ageing treatments on the fatigue crack growth behaviour of AA6013 aluminium alloy was investigated. C(T) (Compact Tension) specimens prepared in L-T and T-L orientations were aged under 3 different conditions: T651-peak aged (as received), T42-natural aged (solution heat treated at 538 °C for 90 min, water quenched and aged at room temperature for 96 h), and overaged (T42 temper + overageing at 245 °C for 12 h). Electrical conductivity and hardness measurements were performed to verify the heat treatments. Fatigue crack growth tests were performed on the samples with a stress ratio of R = 0.1 and a frequency of 4 Hz. In the T-L orientation, the highest fatigue crack growth resistance was achieved for T651 temper. In the L-T orientation, however, T42 + overageing temper exhibited the highest fatigue performance.