摘要
为了提高镁合金耐海水的腐蚀抗力,使用CO2激光对在ZM5上预置不同厚度的Al-Y粉末进行激光合金化。激光合金化后,对涂层的显微结构和显微硬度进行了研究。对所得样品进行浸泡腐蚀实验。结果表明,涂层的相组成为Mg17Al12、Al2Y、Al和Mg。当粉末预置厚度增加时,合金化层中的Al2Y比例增加,Mg17Al12比例随之减少。粉末预置厚度不同,得到的合金化层有三种不同的几何形状,合金化层几何形状在微观上同稀释率相对应。实验得到冶金结合的界面。由于快速凝固过程而获得细小的、白色的具有不同形状特征的含稀土相。涂层的硬度可达到250～325 HV,而基材的硬度仅为80～100 HV。同基材相比,激光处理后,涂层的耐蚀性得到显著提高。
Laser alloyi ng of preplacing Al-Y powder on ZM5 magnesium alloy was earned out with different powder thickness by a CO2 laser in order to improve the corrosion resistance in salt-water （NaCl） solution. The alloying process, the microstructure and the composition were studied. The obtained samples were subjected to immersion tests. The results show that the phases of coating layer consists of Mg17Al12, Al2Y,Al and Mg. The relative proportion of Al2Y increases with the increase of preplaced powder thickness, while the relative proportion of Mg17Al12 decreases. From microscopic point of view, the geometric characteristics are related to the dilution. A good metallurgical bonding interface is obtained. The rapid solidification caused small and white yttrium-containing phases are formed in the alloying layer in different forms. And the microhardness of the alloying zone can be up to 250-325HV, but that of the substrate is only 80-100HV. The corrosion resistance of the alloying samples is enhanced in comparison to the untreated ZM5 substrate.
出处
《热加工工艺》
CSCD
北大核心
2007年第23期33-37,共5页
Hot Working Technology
基金
国家自然科学基金资助项目(50371093)
关键词
镁合金
激光合金化
铝-钇
几何特征
腐蚀
Mg alloy
laser alloying
Al-Y
geometric characteristics
corrosion
