Compression properties enhancement of Al-Cu alloy solidified under a 29 T high static magnetic field

Bulk solidification of Al-40 wt% Cu hypereutectic alloy has been investigated using a high static magnetic field (HSMF). The results show that, by imposing a 29 T HSMF, the melt convection has been completely suppressed in the mushy zone and the whole scale. The primary Al2Cu faceted phase changed to non-faceted phase because of the growth enhancement of Al2Cu precipitates. Al-Al2Cu eutectic was destabilized as a coexisting of lamellar and rod-like α-Al phase under 0 T whereas it was stabilized as a lamellae under the 29 T HSMF. The dimension of primary Al2Cu precipitates has been refined. The interlamellar spacing of eutectic Al-Al2Cu structure has been reduced from 6.3 µm to 2-3 µm. The primary Al2Cu precipitates were almost oriented to its < 001 > crystal direction which was parallel to the direction of the vertical HSMF. The morphologies of shrinkages displays as approximately regular spheres. Compressive strength of Al-40 wt% Cu alloy has been enhanced from 248 MPa to 431 MPa and the maximum stain has been improved from 3.6% to 5%. This paper reveals the effect of HSMF on Al2Cu precipitates, provides a new sight about refinement theory and new pathway to fabricate brittle materials with excellent mechanical properties.