cracking in 2024 Aluminum alloy forged block during heat tretment

[fhadzafar]

We have received a block of 2024 for heat treatment to T4 temper. Its size was 200x 200x 300 mm approx. Customer stated that it is "forged". It was Solution treated and then aged. After ageing the block was split into two halves(crack was not visible at the stage of quenching). The failure started from almost the center of the block. There was a dimple (sinking) on either outer faces of the block in line with the (expected)failure initiation point . Fortunately Tensile sample machined from the same lot of material were also processed with the block. All of the samples failed. Having very low elongation (as low 1.5 ~4%) and low UTS. Failed samples were analyzed by XRF analyzer and was confirmed as AA 2024.
I'm seeking guideline in order to investigate the reason for failure. What could we suspect ? How shall we proceed without loosing evidence?

 

[mrfailure]

You are best served sending this to a lab experienced in metallurgical failure analysis of manufactured components. They'll know what to do.

 

[fhadzafar]

Thanks mrfailure. U r right. We have an optical microscope and micro-hardness tester avaiable with us, which we have purchased recently. It would have been helpful, if somebody could share the macrographs and micrographs of Al-2024 as cast, cast and homogenized, as forged, Forged and annealed, T4, T6 tempered. So we could compare and arrive at some conclusion this way.