超声振动功率对2024铝合金显微组织、显微硬度及耐腐蚀性能的影响

Influence of ultrasonic vibration power on microstructure,microhardness and corrosion resistance property for 2024 aluminum alloy

研究了不同超声功率(0、700、1400和2800 W)对2024铝合金显微组织、显微硬度及耐腐蚀性能的影响。结果表明:2024铝合金在经过超声处理后,其显微组织、显微硬度以及耐腐蚀性能均得到了较好的改善。这是由于超声波在熔体中产生的空化作用对熔体中的固体颗粒产生了强烈作用,击碎了初生枝晶,促进了形核,使晶粒得到了细化,进而优化了该合金的显微硬度(由98.9 HV增加至120.5 HV)和耐腐蚀性能。失重和析氢测试结果表明:与未处理的合金相比较,在对合金进行2800 W超声振动处理后,合金的失重腐蚀速率由0.49 mg·(cm^(2)·h)^(-1)降低至0.25 mg·(cm^(2)·h)^(-1),下降约49.0%;析氢腐蚀速率由0.44 ml·(cm^(2)·h)^(-1)降低至0.21 ml·(cm^(2)·h)^(-1),下降约52.3%。

The influences of different ultrasonic powers,such as 0,700,1400 and 2800 W on microstructure,microhardness and corrosion resistance property of 2024 aluminum alloy were studied.The results show that the microstructure,microhardness and corrosion resistance property of 2024 aluminum alloy are improved after ultrasonic treatment.The reason is that the cavitation produced by ultrasonic wave in the melt has a strong effect on the solid particles in the melt to break the primary dendrite and promote the nucleation resulting in the refinement of grain and the optimization of microhardness which is from 98.9 HV to 120.5 HV and the corrosion resistance property of the alloy.The results of weighthessness and hydrogen evolution tests show that compared with the untreated alloy,after the alloy is subjected to ultrasonic vibration treatment of 2800 W,the weighthessness corrosion rate of alloy is reduced from 0.49 mL·(cm^(2)·h)^(-1)to 0.25 mg·(cm^(2)·h)^(-1),a decrease of about 49.0%,and the hydrogen evolution corrosion rate is reduced from 0.44 ml(cm^(2)·h)^(-1)to 0.21 ml·(cm^(2)·h)^(-1),a decrease of about 52.3%.