石墨纤维增强铝基复合材料表面稀土成膜过程

采用含稀土Ce盐的化学溶液浸泡工艺在石墨纤维增强铝基(Gr/Al)复合材料表面制备无毒、无污染稀土耐蚀膜层,并对不同时间稀土Ce盐在Gr/Al复合材料表面的成膜情况进行研究.铝基体和石墨纤维表面均覆盖稀土膜层,此类稀土膜呈现

Process of rare earth conversion coating on the surface of graphite fiber reinforcement aluminum matrix composites

A Ce conversion coating, which is non-toxic and non-pollution, was prepared by chemical dipping immersion treatment on graphite fibers reinforee aluminum (Gr/Al) eoraposite surface. It is shown that the graphite fiber and aluminum alloy surfaces both are coated by the Ce conversion coating, and the microstructure of the coating is dried-mud-like. Energy dispersive spectroscopy (EDS) indicates that the major elements distributing on the coating are Al, O, C, Si, Ce, and Mg, and the mass fraction of Ce is 14.44wt% after coating for 30 rain but increases to 47.48wt% after coating for 120 min. The formation meehanism of coating mierocracks was put forward. The micro-cathodic formation mechanism can explain the characters of the coatings. The Ce conversion coating becomes a barrier of O₂ diffusion and electron transmitting, and oxygen absorption and hydrogen separation were both inhibited.