Study of porosity defect and Its controlling in WAAM of high-strength AlCuMnZr alloys based on 3D CT images

Pore defect formation mechanism and its control method of high-strength AlCuMnZr alloy fabricated by Wire and Arc Additive Manufacture（WAAM） were studied in this paper. Based on three-dimensional CT image analysis technology, the results of analyzing the porosity defects of thin-walled parts post-treated by natural air cooling（AC）, substrate-forced water cooling（WC） and hot isostatic pressing（HIP） show that the porosity of the WC/AC/HIP specimens are 1.29%, 1.21% and 0.45%, respectively, and that the HIP treatment can effectively reduce the porosity and improve the mechanical properties of the alloys. The tensile strength, yield strength and elongation of AlCuMnZr alloy formed by WAAM under natural air-cooling of the substrate after HIP treatment were（270±18）MPa,（150±8）MPa and（9±1）%, respectively.