高エネルギー密度電子ビーム溶射法の確立に関する研究

本课题的研究目的是开发一种利用高能量密度电子束进行表面改性的新方法，并将其应用于常规热喷涂方法难以实现的致密WC-Co涂层。热源为30kW电子束焊机，材料为WC-12%Co粉末和Ni-Cr自熔合金粉末。采用混合粉末凝固法制备了一层厚度超过800 μ m的WC-Co涂层，该涂层致密均匀地分布在低碳钢基体上的Ni-Cr基体上。采用x射线衍射、EPMA、维氏硬度测试、滑动磨损测试和腐蚀测试对涂层进行了检测。结果表明，该涂层具有良好的耐磨性和耐腐蚀性。分析了高能量密度电子束作用下涂层的形成机理。研制了能在真空条件下工作的给粉机和能在真空中连续形成涂层的电子束喷涂方法。在真空连续进料条件下，获得了与粉末凝固法相似的涂层。

The purpose of this research project is to develop a new surface modification method using high energy density electron beam and to apply it to a dense WC-Co coating which is difficult to achieve with conventional thermal spraying method.A heat source used was a 30kW electron beam welder and materials used were WC-12%Co powders with Ni-Cr self fusion alloy powder.A WC-Co coating of over 800 mum in thickness which dispersed densely and homogeneously in Ni-Cr matrix on mild steel substrate was obtained using the mixed powder setting method. The coating layrs were examined by X-ray diffraction, EPMA,Vickers hardness test, sliding abrasion test and corrosion test. It was found that this coating layrs have enough abrasion and corrosion characteristics. Furthermore, the formation mechanism of coating layr by high energy density electron beam was analyzed.A powder feeder which can function under vacuum condition and electron beam spraying method which can form a coating layr continuosly in vacuum was developed. A similar coating layr as the powder setting method was obtained under a continuous feeding condition in vacuum.