FeBSiNb合金粉末制备及非晶涂层性能研究

Fabrication of FeBSiNb Powder and Its Amorphous Coating

摘要:

采用气雾化制备了FeBSiNb合金粉末,经过火焰喷涂后,制备了高非晶含量的FeBSiNb涂层。利用X射线衍射仪、差热分析仪、扫描电镜和透射电镜分析了粉末和涂层的表面形貌、显微组织和结构特征。结果表明：FeBSiNb合金粉末主要由晶体Fe₂B相和α-Fe(Si)固溶体组成。FeBSiNb非晶涂层主要由非晶相(含量85vol%左右)、Fe₂B晶体相和α-Fe(Si)纳米晶相组成。非晶涂层在531~605℃区间发生晶化,涂层的玻璃转变温度T_g为513℃,晶化温度T_x为531℃,计算得出FeBSiNb系合金形成非晶相的临界冷却速率在2.0×10₆ K/s左右。对涂层的摩擦磨损性能进行测试,在5N,5Hz,30min摩擦条件下,FeBSiNb非晶涂层的摩擦系数仅为0.2左右,相对耐磨性约为45_#钢基体的10倍。

Abstract:

The FeBSiNb amorphous coating was prepared by flame spraying using the alloy powders were fabricated by gas atomization. The morphology, microstructure, phase composition and thermal stability were investigated by XRD, SEM, TEM and DSC. The FeBSiNb alloy powder is composed of Fe₂B crystalline phase and α-Fe(Si) solid solution. The morphology of particle is spherical or elliptical. The FeBSiNb amorphous coating is consisted of amorphous (~85 vol%), Fe₂B crystalline phase and α-Fe(Si) nanocrystalline phase. The crystallization of FeBSiNb amorphous coating occurs around 531~605℃.The glass transition top temperature Tg is about 513℃ and the onset top temperature of first crystallization event Tx is about 531℃. The critical cooling rate for glass formation of FeBSiNb alloy is calculated of about 2.0×10₆ K/s. Under the dry friction condition of 5N, 5Hz, 30min, the friction coefficient of FeBSiNb amorphous coating is only 0.2. The relative wear resistance of amorphous coating was more than 10 times compared with the 45# steel substrate.