SiCp含量及缓蚀剂对SiCp／Al金属基复合材料腐蚀行为的影响

研究了ZL101A铝合金及以其为基体含5vol%,10vol%,15vol%和20voll%SiCP的SiCP/Al金属基复合材料在3.5%NaCl溶液中的腐蚀行为,通过添加钼酸钠、硅酸钠等缓蚀剂在3.5%NaCl溶液中,将SiCP/Al金属基复合材料在室温下浸泡一定的周期,采用失重法和SEM技术分别计算腐蚀速率和分析腐蚀后的微观组织形貌.试验结果表明SiCP颗粒增强物的加入对SiCP/Al金属基复合材料腐蚀速率影响不大,甚至略有降低,SiCP改变了铝合金基体表面腐蚀的形核和发展,点蚀数量增加、深度变浅.添加缓蚀剂后,抑制了SiCP/Al金属基复合材料表面点蚀的形成,与钼酸钠缓蚀剂相比,硅酸钠具有良好的缓蚀作用,当SiCP颗粒增强物的含量达到15vol%和20vol%时,缓蚀剂的缓蚀效果明显下降.

Influence of SiCP content and inhibitor on the corrosion behavior of SiCP/Al metal matrix composites

The corrosion behavior of ZL101A aluminum alloy and silicon carbide particulate/aluminum (SiC_P/Al) metal matrix composites was studied in a medium of aqueous sodium chloride (NaCl) solution,where the SiC_P/Al composites contained 5vol%, 10vol%, 15vol% and 20vol% SiC_P. Corresponding ZL101A base aluminum alloy was subjected to identical test conditions to study the influence of SiC_P on corrosion characteristics. By means of immersion test at room temperature, sodium molybdate (Na_2MoO_4) and sodium silicate (Na_2SiO_3) were used as inhibitors. Weight loss and scanning electron microscopy (SEM) were used to evaluate the corrosion rate and surface microstructure of the SiC_P/Al metal matrix composites. The results show that average corrosion rate do not vary greatly in relation to the amount of SiC_P reinforcement, even some degree of decrease. Normal pit initiation and propagation were altered by the presence of the SiC_P reinforcement. Pits on the SiC_P/Al composites were significantly more numerous, shallow, and wide spread than on the ZL101A matrix materials.It was found that more effective to prevent the pit initiation on the surface of the SiC_P/Al composites with Na_2MoO_4, Na_2SiO_3 .No obvious effectiveness was observed when containing of the SiC_P reinforcement with 15vol% and 20vol% in the SiC_P/Al composites.