造渣剂对激光熔覆制备铁铝金属间化合物的影响

Effect of slagging flux on Fe-Al intermetallic coatings synthesized by laser cladding

通过激光熔覆添加和不添加造渣剂的铁铝混合粉末在Q235钢基体上制备出铁铝金属间化合物熔覆层,研究了造渣剂对熔覆层的组织和性能的影响.结果表明,向熔覆粉末中添加造渣剂不仅可以显著细化熔覆层晶粒,还可以影响熔覆层的物相结构.当熔覆粉末中Fe,Al原子比例接近3:1时,所制备的熔覆层均由B2结构的FeAl相和DO3结构的Fe3Al组成,但添加造渣剂后所得熔覆层中含有较多DO3结构的Fe3Al.结果表明,添加造渣剂的熔覆层有着更高的显微硬度、更好的抗氧化性能和耐蚀性能.

The iron-aluminide intermetallic coatings were in-situ synthesized on Q235 steel by laser cladding. The cladding powders were mixed iron and aluminum powders with or without slagging flux. The effects of slagging flux on the microstructure and properties of the cladding coatings were studied. The results indicate that adding slagging flux into the cladding powders not only refines the grains of the cladding layers,but also has a significant influence on the properties of the iron-aluminide coatings. The XRD results show that the main phases of the iron-aluminide coatings both are FeAl with B2 phase structure and Fe3 Al with DO3 phase structure,but the ratio of Fe3 Al increases as slagging flux was added. In addition,the iron-aluminide cladding layers with slagging flux shows higher microhardness,better oxidation resistance and better corrosion resistance than those free of slagging flux.