Thin-walled　A357　aluminum　alloy　components　were　built　through　wire-arc　additive　manufacturing.　The　microstructure　and　mechanical　properties　of　the　as-deposited　and　heat-treated　components　were　investigated.　Experimental　results　from　computerized　tomography　(CT)　showed　that　the　amounts　and　morphologies　of　micropores　varied　from　the　top,　middle,　and　bottom　of　all　the　components.　The　strength　and　elongation　of　the　as-deposited　and　heat-treated　samples　exhibited　close　to　isotropic　characteristics.　Subsequent　post　heat　treatment　significantly　improved　the　micro　hardness　and　strength　of　the　deposited　A357,　due　to　the　large　amounts　of　dispersed　nanoscale　Si　particles　in　the　Al　matrix.　©　2020　Elsevier　B.V.