Crack propagation in 5052 H32 aluminum sheet

[joelande]

I have a question about the potential for crack propagation in both .080 and .063 sheet. We currently laser cut and turret punch shapes into these sheets. All things being equal, I am wondering if either method has some inherent advantages/disadvantages as far as the tendency to start fatigue cracks. My guess is that the laser would be worse for this because of the HAZ along the cut.

 

[metengr]

There is not enough information to provide a recommendation because of numerous variables involved even making a general assumption of things being equal.
Here is some advice - if you are really serious about wanting to quantify the affects of laser versus punching for this material send a few samples over to a metallurgical lab and have them evaluate the cut edges by performing microhardness traverses and evaluate the condition of the edge using metallographic examination or even high magnification, a scanning electron microscope (SEM).
The lab results can be used to evaluate performance of the part in service.