Hybrid articles comprising a molded mixture of a light metal alloy and a polymer are formed by processing (including co-molding and co-extruding) the metal in a semi-solid state at a high shear rate and the polymer in a melt processable state. For example, magnesium alloy particles in a thixotropic condition are mixed with particles or globules of the polymer and molded into a hybrid metal-containing and polymer-containing body. The proportions of magnesium and polymer may be varied substantially depending on the desired properties of the hybrid article. In another embodiment the light metal and polymer may be co-extruded as two or more distinct layers into a solid or hollow hybrid body.