石墨烯/锌基复合材料在模拟体液中的腐蚀行为研究

石墨烯增强锌基复合材料具有良好的力学性能,有望作为可降解医用植入材料用于人体骨骼修复。为了明确石墨烯添加对锌基复合材料降解行为的影响,本文采用电化学方法和浸泡法对比研究了纯锌、石墨烯/锌基复合材料在人体模拟体液(SBF)中的腐蚀行为。结果表明随着石墨烯含量增加,试验材料的腐蚀速率加快,腐蚀形式以均匀腐蚀为主,腐蚀产物主要为ZnO。     

Microstructure evolution of Al-Si semi-solid slurry by gas bubble stirring method

A novel technique of introducing gas bubble stirring during solidification was studied to prepare Al-Si semi-solid slurry. The microstructure evolution of the slurry during slow cooling process after stirring was investigated. The effects of the solidification rate on the microstructure of the semi-solid slurry were investigated under three different solidification conditions. The results show that fine non-dendritic slurry can be obtained using the gas bubble stirring method. Ripening and coarsening of primary Al grains are observed during the slow cooling process, and at last coarsened eutectic Si appears. Primary Al grains with different sizes and eutectic Si are obtained, corresponding to three different solidification rates.