| 7072Al alloy is one of the important heat-transfer materials, which is widely used as cladding layer of heat-exchanger. In this paper, the influence of Zn content on the microstructure, mechanical properties and electrochemical properties of simulated-brazing and annealed 7072 Al alloy were investigated.For the simulated-brazing alloy, Zn-addition could promote the precipitation in the 7072 Al alloy. The promotion for precipitation was evident for the alloy with 1.3% Zn addition. Further Zn addition will not affect the precipitation density too much. Tensile testing results indicated that, in comparison with 7072 Al alloy, the mechanical properties were improved after Zn-addition. Electrochemical testing results revealed that, with the addition of Zn element, the corrosion potential of the simulated-brazing alloy showed a negative shift.For the annealed alloy, the density of precipitates and mechanical properties of 7072 Al alloys with different Zn addition were close. The corrosion potential and corrosion current were also close for 7072Al+1.3%Zn and 7072Al+1.5%Zn alloys. Compared to the 7072Al+1.3%Zn and 7072Al+1.5%Zn alloys, the corrosion potential of the 7072Al+2.5%Zn alloy showed a negative shift and corresponding corrosion current increased.The corrosion degree of the simulated-brazing and annealed alloys increased with increase of Cl- concentration in the NaCl solution. In 1M NaCl+0.3M H2O2 solution, the corrosion current of all samples significantly increased and corrosion was more serious. |
PDF Full Text Request