激光熔覆Fe-Ni-Si-B非晶层的形成条件

Forming conditions of Fe-Ni-Si-B amorphous coating by laser cladding

关键词:  激光  非晶化  涂层

Key words:  laser  amorphization  coating

摘要:

采用5 kW横流CO₂激光器在45钢基体上激光熔覆制备了Fe₃₈Ni₃₂Si₁₆B₁₄的非晶层。利用X射线衍射和透射电镜分析了熔覆层物相、组织结构与非晶形成的影响因素。结果表明,B以硼铁的形式加入有利于非晶层的形成;Si含量为16%时非晶层形成能力达到最大,Si在作为合金组元的同时还起到防止其他元素氧化烧损的作用,其含量影响到合金系的玻璃形成能力;激光功率和光斑直径一定时,扫描速度影响熔池的均匀化程度和冷却速度。在激光功率4800 W,扫描速度3500 mm/min时,可以实现激光表面非晶化。

Abstract:

A Fe-Ni-Si-B amorphous coatings was prepared by laser cladding on the substrate 45 carbon steel with a 5 kW continuous CO₂ laser.The phases, microstructure and the forming conditions of the amorphous coatings had been studied using X-ray diffractometer and transmission electron microscope.The results show the addition form of the boron iron is better than the B powder during the synthesis of the amorphous coatings.The glass forming ability of the alloy increases with increasing Si content and reaches maximum when it reaches 16 at.%.Si can protect the other components from oxidation and burning when it acts as a major composition in the alloys.The laser scanning velocity has influences on composition homogeneity and cooling rate of the melting pool under the given laser power and beam diameter.Amorphous alloys an be developed when the laser power is 4800 W and the scanning velocity reaches 3500 mm/min.