摘要
通过光学显微镜(OM)、扫描电子显微镜(SEM)、X射线衍射仪(XRD)分析手段对加速腐蚀环境下的Zn-2Al钎料的组织和性能进行研究。结果表明:随着腐蚀时间的延长,钎料中O,H含量不断增加;Zn-2Al钎料抗拉强度和延伸率随着腐蚀时间的延长逐渐降低;腐蚀深度与腐蚀时间呈线性关系:D=A+Bt,其中A=-30.50083,B=34.81966,Zn-2Al钎料的腐蚀没有自抑制倾向;水汽腐蚀主要发生在晶界处,当腐蚀达到一定程度后,形成了大量的腐蚀裂纹和腐蚀孔洞;应力的存在加剧了Zn-Al钎料在湿热环境中的晶间腐蚀,易在晶界处形成腐蚀裂纹,腐蚀环境对裂纹的扩展有明显的加速作用,裂纹沿着晶界处不断扩展;晶间腐蚀过程是晶内富锌β相作为阴极,晶界处富铝α相作为阳极而溶解的电化学腐蚀过程;XRD分析结果显示腐蚀产物主要有Al2O3,Zn O,Al(OH)3,Zn(OH)2,与前面所测腐蚀后钎料中氧氢含量增加相一致,钎料在湿热环境中进行着电化学腐蚀并伴随着氧化。
The microstructure and mechanical properties of Zn-2Al in accelerated corrosion environment were researched by optical microscope（ OM）,scanning electron microscopy（ SEM） and X-ray diffraction（ XRD）. The results showed that the oxygen and hydrogen contents of Zn-2Al brazing filler metal increased and the tensile strength and elongation decreased with the corrosion time extending. The relationship between corroding depth and corroding time could be expressed as D = A ＋ Bt,A =- 30. 50083,B = 34. 81966,and the corrosion of Zn-2Al had no self-inhibition tendency. When the water vapor corrosion which primarily occurred at grain boundaries reached some degree,corrosion cracks and holes formed. The stress exacerbated the intergranular corrosion of Zn-Al in muggy atmosphere,and the corrosion environment significantly accelerated the expansion of cracks along the grain boundaries. The intergranular corrosion proceeded with intragranular zinc-rich β phase as a cathode,and aluminum-rich α grain boundary phase as the anode to dissolve. XRD results showed that corrosion products were mainly Al2O3,Zn O,Al（ OH）3and Zn（ OH）2,which were consistent with the previously measured results of oxygen and hydrogen content. The solder in muggy environment underwent electrochemical corrosions with oxidation.
出处
《稀有金属》
EI
CAS
CSCD
北大核心
2014年第6期993-998,共6页
Chinese Journal of Rare Metals
基金
国家自然科学基金项目(51275351)
国家科技支撑计划项目(2012BAB18B04)
国家科技部"863"计划项目(2012AA0402208)资助
关键词
Zn-2Al钎料
加速腐蚀
湿热环境
Zn-2Al filler metal
accelerated corrosion
muggy environment
