含钐Al-Mn-Si-Fe-Cu合金的显微组织与耐腐蚀性

摘要

优化合金成分是改善汽车热交换器材料物理化学性能的有效途径.采用透射电子显微镜(TEM)和扫描电子显微镜(SEM)观察,电化学测试和酸性人造海水盐雾试验(SWAAT)等方法研究了一种新型翅片材料-含钐Al-Mn-Si-Fe-Cu合金的显微组织与耐腐蚀性能.研究结果表明:合金中的主要析出相为α-Al(Mn,Fe) Si,同时形成含钐析出相Al2Sm和Al10Cu7Sm2.Sm元素的添加可细化α-Al(Mn,Fe) Si析出相.Tafel极化曲线测试结果表明:腐蚀表面主要由点蚀坑和腐蚀产物组成.随着Cl-浓度的增大,合金的腐蚀程度加深.SWAAT则表明,随着腐蚀时间的延长,腐蚀失重先加剧后减缓.%Optimizing alloy composition is an effective way to improve physical and chemical properties of automobile heat exchanger materials.A Sm-containing Al-Mn-Si-Fe-Cu alloy was investigated through transmission electron microscopy,scanning electron microscopy,and electrochemical measurement.Experimental results indicated that main phases distributed in the alloy wereα-Al(Mn,Fe)Si,Al2Sm and Al10Cu7Sm2.Alloying with Sm element could refine the precipitated α-Al(Mn,Fe)Si phase.Polarization testing results indicated that the corrosion surfacewas mainly composed of pitting pits and corrosion products.Sea water acetic acid test(SWAAT) showed that corrosion loss increased first and then slowed downwith increase of the corrosion time.