【作者】 朱冬妹；

【导师】 王惜宝；

【作者基本信息】 天津大学 ， 材料加工工程， 2006， 硕士

【摘要】 本文采用铝线材通过电弧喷涂加等离子熔覆复合技术在Q235钢基体表面原位合成制备了Fe₃Al金属间化合物涂层。通过金相显微镜、X-ray衍射、扫描电子显微镜等手段对原位合成的Fe₃Al金属间化合物涂层的组织结构和性能的研究后认为,利用上述方法能够原位合成制备Fe₃Al金属间化合物涂层。该涂层由Fe₃Al、FeAl、Al₂O₃、α-Fe相组成;熔覆层组织形态为粗大的柱状晶,在粗大柱状晶内有大量Fe₃Al针状物析出,针状的析出物的排列方向是不同的,呈不规则排列;随着熔覆过程中温度的增加,熔覆层组织中Fe₃Al晶须的数量和大小有所增加。在熔覆区与热影响区交界处存在白亮带,它是以平面晶的生长形态沿热流方向生长出来的,并与热影响区之间保持着平直界面。白亮层的形成表明涂层与基体实现了良好的冶金结合。从基体到熔覆层形成有一定宽度的显微硬度渐变区,硬度变化是:表面层硬度较高,过渡区硬度降低,基体部分硬度最低。该等离子熔覆层很好的提高了基体材料硬度和耐磨蚀性能。该种方法不仅可以用于制造特定条件下使用的新零件,节省大量贵重材料,还可以用于修复失效零件,显著延长其使用寿命,因而具有重要的社会效益和经济效益。更多还原

【Abstract】 In this paper, coating and PTA （plasma Transferred arc） surfacing process are used to synthesize in-situ Fe 3 Al inter-metallic compound coating on mild steel substrates （Q235）. The microstructure and composition of the coating were investigated by optical microscopy, X-ray, scanning electron microcopy. It is found that the Fe 3 Al inter-metallic compound coating can be synthesize in-situ during the coating and PTA cladding process.The coating consists of phase Fe 3 Al、FeAl、α-Fe and Al₂O₃. The structural morphosis is the coarse columnar grain, which is composed of a lot of fine lath Fe 3 Al needle grains. The orientations of needle grains are different and distributed randomly. Following the increasing of the temperature of test plate, the Fe 3 Al whiskers in the coating become large and the quantities are increasingly. The white-bright band occurred between the coating and the substrate, which proved metallographic bond. The hardness of the coating rise increasingly from the substrate line to the surface of Fe 3 Al inter-metallic compound coating. The clad alloying coating has the maximum hardness value, reduce sequentially to the base body in the alloying area, and the hardness value of substrate is least. The coatings have increased the hardness of the base body greatly and well anti-friction.This method can be used both to manufacture new parts and to repair the invalid parts used under special conditions. It has very important social and economic benefits.更多还原