Investigating Synergistic Mechanisms of Porous Injection-Flux for Hydrogen and Impurity Removal of Aluminum Alloy

To improve the metallurgical quality of the melt prior to the holding furnaces and reduce the subsequent refining burden, it is essential to intensify early-stage melt purification. To overcome the limitations of conventional purification technologies, including complex equipment and high costs, an efficient purification method for aluminum alloy (6111) based on porous injection-flux synergy is proposed. Through systematic optimization of key process parameters, the intrinsic coupling mechanism for hydrogen degassing and inclusion removal is clarified. Porous injection generates fine bubbles that reduce hydrogen partial pressure and enlarging the gas-liquid interfacial area, thereby accelerating hydrogen mass transfer. Simultaneously, flux reactions form microbubbles and lower interfacial energy, promoting spontaneous inclusion adsorption, while bubble-induced turbulence enhances flux dispersion and inclusion collision probability. Under optimal conditions (400 L/h gas flow, 0.7 wt pct flux, 15 minutes treatment) for a 10 kg melt, hydrogen content decreased by 75.4 pct to 0.15 mL/100gAl, and the inclusion area fraction was reduced to 0.68 pct. Resultant as-cast properties improved to 70 HV hardness, 143.23 MPa tensile strength, and 10.1 pct elongation. Compared with conventional rotary degassing or single flux treatment, the proposed strategy enables simultaneous degassing and inclusion removal via thermodynamic–kinetic coupling, offering a basis for integrated melt purification design.