An ultrafine-grained (UFG) microstructure was obtained in a bulk billets 20x20x80mm out of Al-based alloys by Equal Channel Angular Pressing (ECAP) at the ambient temperature with a different number of passes and backpressure levels. In brittle cast non-heat treatable Al-5wt.%Fe supersaturated solid solution of iron in an aluminium matrix was processed during 16 passes of ECAP with backpressure 275 MPa. Strength, ductility and microhardness of the ECAP alloy were significantly enhanced. An increase in a backpressure retards cracking of intermetallic particles and enhances workability and ductility of ECAP alloys. The room strength and microhardness of initially course-grained AA5083 alloy, subjected to ECAP with backpressure 20 MPa, are much higher than its standard values after conventional processing.