Caliber Rolling Process and Mechanical Properties of High Fe-Containing Al–Mg–Si Alloys

Abstract

Fe-intermetallic compounds are commonly detrimental for mechanical properties and formability of aluminum alloys. In this study, the refinement of Fe-intermetallic compounds and mechanical properties in high Fe-containing AlMgSi alloys were studied by caliber rolling. The Al(2.22.3) mass%Si0.9 mass%Mg(1, 1.5 and 2) mass%Fe alloys were severely deformed by the multi-pass caliber rolling at 573 and 723 K. Fe-intermetallic compounds were finely fragmented with the smallest size of around 200 nm. The morphologies of fragmented Fe compounds in the Al matrix depend on the as-cast microstructure and deformation behavior with better distribution in the outer area than in the center area. Good ultimate strength of 345360 MPa and high elongation of 1525% were achieved after 95% caliber rolling.

Microstructural Evolution and Mechanical Properties of Pure Aluminum upon Multi-Pass Caliber Rolling

“…The formation of sub-grains led to a significant reduction in the proportion of the original HAGBs in as-rolled samples compared to the as-cast counterpart. As the deformation moved forward, the sub-grain boundaries would change to HAGBs, resulting in the Vf of HAGBs increasing again, and it was agreed well with previous studies [ 11 , 19 ].…”

“…However, in low-SFE fcc materials, {111}<112> twinning will contribute a greater degree of deformation. In briefly, for high SFE materials, copper-type texture {100}<110> dominates; for low SFE materials, brass-type texture {112}<110> dominates [ 19 , 26 ]. Figure 6 showed the orientation distribution function (ODF) mapping of as-cast and as rolled pure Al.…”

“…The original HAGBs have an obstructive effect on the motion of dislocations, making them obstructed at GB. Step by step, the interaction of dislocations will generate dislocation cells [ 16 , 19 ]. Figure 8 c showed the density of dislocation increased and more and more dislocation were blocked at GBs.…”

“…Recently, one SPD, called caliber rolling, showed advantages for mass production of bulk materials with an ultra-fine grain (UFG) in not only traditional steel but also non-ferrous metals (i.e., Al [ 19 ], Mg [ 20 ] alloys). For instance, the caliber rolled Al-Si-Mg-Fe alloy shows Fe-intermetallic compounds refined to about 200 nm, given UTS and elongation (El.)…”

Precipitation behavior of Al-Si-Cu-Mg(-Fe) alloys by a deformation-semisolid extrusion process

“…Recently, the negative effect of Fe-IMCs on the mechanical properties has been reduced by deformationsemisolid forming (D-SSF) and caliber rolling processes [4][5][6]. The D-SSF process is an effective method for breaking Fe-IMCs and inducing large strain in the Al matrix.…”