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含稀土耐蚀Mg-9Al铸造镁合金腐蚀行为研究 总被引:1,自引:0,他引:1
通过盐雾、失重及析氢等腐蚀试验研究了新研制的含稀土的Mg-9Al铸造镁合金AR091在3.5%NaCl溶液中的腐蚀行为,并与目前常用的ZM5和AZ91D镁合金的腐蚀行为进行了对比。结果表明,AR091具有良好的耐腐蚀性能。AR091的微观组织与AZ91有明显差别,其晶粒更为细小,β相明显减少,还存在许多针状含稀土元素(RE)的析出相。合金内各相间的微电偶腐蚀明显减弱,阴极反应过程受到抑制。采用场发射扫描电镜(FESEM)及俄歇电子谱(AES)研究比较了合金的表面腐蚀产物膜,结果表明,在AR091合金表面能形成更为致密、保护性更好的腐蚀产物膜。 相似文献
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针对镁合金作为镁电池负极材料存在着自腐蚀速率大、负极利用率低、电压滞后等问题,采用恒温浸泡、极化曲线、恒电流放电等手段对AZ31(挤压态)镁合金和纯镁(铸态)进行了试验研究和分析。研究了AZ31和纯镁在浓度为1.0 mol/L,1.5 mol/L,2.0 mol/L的MgSO4,Mg(ClO4)2,MgCl2和Mg(NO3)2溶液中的腐蚀行为和电化学性能,具体分析了AZ31在不同电解液中的电化学行为。结果表明,AZ31在MgCl2溶液中的自腐蚀速率较高且生成较厚的腐蚀产物膜,严重降低了电极的利用率,在MgSO4溶液中则常常发生点蚀,不适宜用作镁电池负极材料,而在Mg(ClO4)2和Mg(NO3)2溶液中具有相对较好的耐蚀性能和放电效率。 相似文献
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Based on the previous investigation on beneficial introduction of holmium into magnesium alloy, the effect of gadolinium, an adjacent rare earth element, on corrosion resistance was examined. The corrosion behavior of two Mg-9Al-Gd alloys (Mg-9Al-0.45Gd and Mg-9Al-l.43Gd) was evaluated and compared with that of Mg-9Al alloy without Gd by means of specimen mass loss and hydrogen evolution in 3.5% NaCl solution saturated with Mg(OH)2. The Gd-containing alloys exhibit enhanced corrosion resistance with respect to the plain Mg-9Al alloy. The microstructures of Mg-9Al alloy and Mg-9Al-0.45 Gd alloy were observed by electron probe microanalysis (EPMA) and energy dispersion spectroscopy (EDS). The alloys with Gd addition show a microstructure characterized by a phase solid solution, surrounded by minor amount of β phase and more grain-like Gd-containing phase. To illustrate the involved mechanism their polarization curves were recorded. The electrochemical investigations reveal that Gd addition shifts the corrosion potential of the alloy towards active, as Gd containing phase is more active and hence less cathodic. As a result, the micro-galvanic corrosion is suppressed. Moreover corrosion product films formed on the Gd containing alloys are more compact and provide a better protective effectiveness than that on the alloy without Gd against corrosion. Repassivation measurements in mixture solution of 0.21 mol/L K2CrO4+0.6 mol/L NaCI also verify the beneficial role of Gd addition. Based on the present preliminary analysis, both the deposited Gd-containing phases and corrosion product films are believed to be responsible for the improved corrosion behaviour due to Gd addition. 相似文献
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智能变电站对保护安装方式和检测要求提高,原有保护系统存在传输速度慢和架构复杂导致可靠性不高等问题,在此背景下,提出对数据进行分流处理交换,采用k-means算法与业务优先级分层管理技术保证数据实时性,并以FPGA作为通信并行的协处理器,提高处理器和FPGA之间的传输效率.基于以上架构研发出基于k-means算法的电力系统SoC芯片继电保护装置.该装置通过实时数字仿真系统RTDS(RTDS)的故障录波图确定保护装置的动作时间,证明该装置的可靠性和实用性,最后将研发的继电保护装置应用于南方电网部分智能变电站中进行了三年的运行,结果表明其运行可靠稳定,实现保护就地化,装置小型化、高防护、低功耗,达到预期的效果. 相似文献