The effect of barium on the refinement of primary aluminum and on the modification of eutectics in a hypoeutectic aluminum-silicon alloy was investigated. The results indicate that barium not only modifies the eutectic silicon but also refines the primary aluminum and there is a relationship between the retained barium and the second spacing of primary aluminum. Experiments of barium-treated commercial Al-Si hypoeutectic alloy show that barium is a better modifier than sodium when there is a longer holding time.

用挤压铸造方法制各Mullite/Al-Cu复合材料及其基体合金。用硬度测试（HB）、差示扫描量热仪（DSC）和透射电镜（TEM）等手段，研究了温度和溶质原子浓度对复合材料及其基体合金时效行为的影响。结果表明：复合材料和基体合金具有相似的时效硬化曲线及相同的时效析出序列，随时效温度的升高，峰值硬度降低、析出过程加快；溶质浓度升高，峰值硬度升高、析出过程同样得到加快；纤维除了能明显提高Al-Cu合金的时效硬度外，还能加速其时效析出过程，但对GP区的形成具有明显的抑制作用，而对θ相的析出影响不大。

研究了溶质原子浓度、Si晶体第二相、残余形变、外加莫来石（Mullite）短纤维及其交互作用，对二元Al-Cu合金时效析出行为的影响。试验材料采用挤压铸造方法制备，复合材料中纤维体积分数为18%。实验结果表明：随溶质原子浓度的升高，Al-Cu二元合金中GP，θ″和θ′相的析出都得到了相应加快；Si含量超过一定值后，随Si含量增加，Al-Cu-si合金中GP区形成受到抑制，而θ″和θ′相的析出得到加快；形变对GP区的抑制和对θ″，θ″和θ相的加速析出具有十分明显的作用；纤维本身除对GP区抑制和对θ″，θ′相的析出加速外，还会与溶质原子、合金元素或第二相以及残余形变交互作用，使GP区被抑制，而θ″，θ/甚至θ相被加速析出等现象进一步加强。用位错理论能较好地解释析出反应延缓与加速的微观机理。

Recently, the studies on application of rare earth (RE) in spray-welding materials has attracted more and more attention. Iron base fluxing alloy powder has been widely used as spray-welding materials due to some of its advantages, such as lower price and good wear resistance. However, its oxidation resistance at high temperature is poor, therefore, RE has been used to improve its properties in the present study. The iron base fluxing alloy powder containing mixed RE alloy were prepared by using the smelting-atomizing process, the coating samples were prepared by using the oxide-acetylene flame spraying process. And the effect of RE on oxidation resistance of iron base fluxing alloy spray-welding coating has been studied. Moreover, the oxide layer of the coating samples was analyzed by using scanning electron microscope (SEM) and the X-ray of electron dispersion analysis (EDAX). It has been shown that the addition amount of mixed RE alloy of 0.2 wt% is suitable. Based on the experimental results the mechanism of RE function has been discussed.

根据外科刃具材料的性能要求，设计并制备了用于外科刃具的Ti（C，N）基金属陶瓷。通过在两种医疗消毒介质中的腐蚀实验，评价了该材料的耐蚀性，并讨论了其分别在两种消毒介质中的腐蚀机理。结果表明，Ti（C，N）基金属陶瓷具有良好的耐蚀性，其在医疗消毒用次氯酸盐溶液中主要为电化学腐蚀，而在H2O2水溶液中则以氧化腐蚀为主。