Influence of hybrid extrusion and solution treatment on the microstructure and degradation behavior of Mg-0.1Cu alloy

•Structure and performance of Mg-0.1Cu alloy are tailored via extrusion, solution treatment and their combination.•Content of second phase, and grain size distribution are investigated as the main influences on corrosion.•The dissolution of Mg2Cu phases after solution treatment significantly reduces the corrosion rate of the as-cast alloy.•Grain growth and non-uniformity of recrystallized gain size are observed for the as-extruded alloy after solution treatment.•The solutionized alloy show better corrosion resistance than the extruded and solutionized alloy. Effects of hybrid extrusion and solution treatment on the microstructure and corrosion behavior of Mg-0.1Cu alloy in Hanks’ solution are studied. The applied processing treatment is noted to alter the alloy microstructure. The amount of Mg2Cu precipitation is significantly reduced by the solution treatment. The decrease of secondary phases relieves occurrence of galvanic corrosion and the lowest corrosion rate achieved for the as-solutionized alloy at 510 °C is approximately 1/53 of that of the as-cast alloy. Grain refinement after extrusion results in better corrosion resistance compared with the as-cast alloy. However, the as-extruded Mg-0.1Cu alloy after the solution treatment shows higher degradation rate than the as-solutionized alloy. It is due to the uniformity of recrystallized grain size may play prominent role on the corrosion compared with the dissolution of the Mg2Cu phase by solution treatment.