Microstructure and properties of AZ31 magnesium alloy with rapid solidification

Rapidly solidified (RS) AZ31 magnesium alloy ribbons were made using melt spinning technique. The results show that its microhardness increases with the wheel speed, and after heat treatment, the microhardness of the ribbons produced at 1 600 r/min also increases. Rapid solidification leads to reduction of grain size. When the wheel speed reaches 1 600 r/min, no Mg17 Al12 phase precipitates, while heat treatment at 200℃ leads to precipitation of Mg17 Al12 phase. Al-Mn intermetallic compounds with size no larger than 10 nm appear in as-spun ribbons. The corrosion potential of the as-cast ingots is lower than that of the as-spun ribbons.     

酸性红B在臭氧和高压电晕反应器中的降解

本实验采用臭氧与高压电晕联用技术处理酸性红B染料废水,发现处理15min后pH从5．6降到3．5;电导率从0．45mS／cm增加到0．67mS／cm;通过离子色谱仪测定,处理后的溶液中N03离子从0增加到60mg／L,SO4^2-从0增加到130mg／L,说明酸性红B中S和N元素完全分解后分别生成N03和S02-。臭氧与高压电晕联用处理8min废水完全脱色;联用处理15min,COD去除率为64．3％。废水中CO3^2-的存在对脱色效率影响不大。因此臭氧与高压电晕联用方法具有很好的脱色效果,对去除COD具有协同作用,处理速度快,效果好。