Effect of heat treatment on notch sensitivity factor for aluminum alloys

الملخص EN

This study is concerned with the effect of heat treatment (precipitation hardening) on notch sensitivity factor for aluminum alloy (7075) .

Tests were conducted on four configurations of specimens, three of them which had external circumferential notches with notch radii of 0.5 mm, 0.7 mm, and 1 mm.

The fourth configuration is un-notched specimens.

The alloy samples which were used in fatigue test were subjected to cold working before heat treatment.

Dimensions and roughness of the specimens were measured.

The fatigue tests were performed for different types of specimens.

The (S-N) equation was derived for each group to estimate the fatigue life under any applied stress amplitude.

In addition, the strength reduction factor (kf) and notch sensitivity factor (q) were calculated.

The results showed that the fatigue strength reduction factor were increased after heat treatment and with decreasing notch radius.

Also the notch sensitivity factor increased with increasing notch radius and after heat treatment.

The enhancement percentage in notch sensitivity factor after the heat treatment for 1 mm radius notch was (22.616%) .