原位TiC-TiB2/Al-12Si混杂铝基复合材料组织及腐蚀性能研究

Investigation on the microstructures and corrosion properties of in-situ TiC-TiB2/Al-12Si hybrid aluminum matrix composites

摘要:

采用激光沉积制备了原位TiC-TiB2/Al-12Si混杂铝基复合材料，通过XRD、OM、SEM、TEM和电化学测试分析了复合材料的微观组织和耐蚀性能。结果表明，原位TiC为细小弥散分布的多边形状、TiB2为短棒状，两者均可作为Al的异质形核核心而细化晶粒。在3.5% NaCl溶液中，随着原位TiC-TiB2增强相含量的增加，复合材料的自腐蚀电位正移，自腐蚀电流密度降低，阻抗模量值及相位角值增大，表明复合材料的耐蚀性增强。

Abstract:

In-situ TiC-TiB2/Al-12Si hybrid aluminum matrix composites were fabricated by laser deposition. The microstructures and corrosion properties of in-situ TiC-TiB2/Al-12Si hybrid aluminum matrix composites were analysized by XRD、OM、SEM、TEM and electrochemical test. The results show that the in-situ TiC particles with fine and uniform polygons and the TiB2 particles with rod-like can act as the heterogeneous nucleation core of α-Al phase to refine grains. With the increasing of in-situ TiC-TiB2 particles, the corrosion potential shifts positively, the corrosion current density decreases significantly, and the impedance modulus and phase angle increases gradually, indicating that the in-situ TiC-TiB2/Al-12Si hybrid aluminum matrix composites has better corrosion resistance.