采用XRD、SEM和EDS等分析了Kanthal MoSi2发热元件的微观组织结构和性能。结果表明:其主要组成为MoSi2、铝硅酸盐玻璃相和Mo5Si3;断裂以沿晶断裂为主,并具有一定的解理特征;基体晶粒大小约为9μm,在基体晶粒之间分布着大小不等、呈岛状的黑色物相。MoSi2发热元件表面有一层20μm厚,以SiO2为主,包含少量Al、Ca、Mg、Fe、Na和K的氧化物的玻璃保护膜,保护膜比较均匀平整,和基体之间界面清晰,二者结合紧密,因此具有比较高的物理和力学性能。
The microstructure and properties of Kanthal MoSi2 heating element were studied by X-ray diffraction analysis (XRD),scanning electron microscope (SEM) and energy dispersive spectrometer (EDS). The results showed that MoSi2,aluminosilicate and MosSi3 were the main contents of Kanthal MoSi2 heating element. Intergranular fracture with small fraction of transgranular was its character. The grain size was about 9 μm. Aluminosilicate grains were distributed as islands among the matrix. A homogeneous and smooth glass film was found on the surface of MoSi2 heating element, composed of SiO2 as major component and little amount of Al2O3, CaO, MgO, Fe2O3, Na2O and K2O. With thickness of about 20 μm, the film was closely combined with the matrix but a clear interface between them. Therefore, Kanthal MoSi2 heating element is characterized by good mechanical and physical properties.