铁中硅元素对铝/铁复合板界面金属间化合物生长的影响

Effect of Si in iron on formation and growth of interfacial intermetallic compounds in Al/Fe composite sheet

使用SEM,EBSD研究(480~640)℃1h退火后,铁中添加不同的硅含量(u(Si)=0.82%,1.48%,3.26%)对铝/铁复合板界面金属间化合物生长的影响。结果表明:(480~640)℃1 h退火后,未添加硅的铝/铁复合板在界面处均生成连续金属间化合物,随着退火温度升高,金属间化合物厚度增大,当退火温度超过620℃时,界面金属间化合物形貌由较为平直转变为舌状突起;640℃1 h退火后,界面金属间化合物厚度随铁中硅元素含量的增加呈指数型减小,未添加硅的铝/铁复合板界面金属间化合物厚度在35 μm以上,而铁中添加ω(Si)=3.26%的铝/铁复合板界面金属间化合物厚度为20 um左右;铝/铁复合板界面金属间化合物主要为Fe_(2)Al_(5),少量的Fe_(4)Al_(13)分布在靠近铝侧和分散在Fe_(2)Al_(5)中;铁中添加ω(Si)=1.48%时,界面金属间化合物同样包括Fe_(2)Al_(5)及少量的Fe4Al13,其分布与不加硅的铝/铁复合板的类似,只是其界面还生成了含硅的Fe_(3)Al_(2)Si_(3)和FeAl_(2)Si相,他们弥散分布于靠近铁侧的Fe_(2)Al_(5)中。

The effect of adding ω(Si)=(0.82%,1.48%,3.26%)in iron on the forma-tion and growth of interfacial intermetallic compounds upon annealing at temperatures(480,520,560,600,610,620,630,640)℃ for 1 h in AlFe composite sheet was investigated bySEM and EBSD analysis.The results show that continuous intermetallic compounds areformed at the interface of pure Al/Fe composite sheet upon annealing at temperature of(480,520,560,600,610,620,630,640)℃ for 1 h.The thickness of the intermetallic com-pounds increases with the increase of temperature.When the temperation is beyond 620℃,the morphology of the interficial intermetallic compounds changes from flat to tongue-like protrusion.Specially,when annealing at 640℃ for 1 h,the thickness of the interficial interme-tallic compounds decreases with the increase of Si concentration in the iron part.The formedinterfacial phase in Al/Fe is 35 m and beyond in thickness,when ω(Si)=3.26% is add-ed to the iron side,the interficial intermetallic compounds of Al/Fe is about 20μm in thick-ness.Fe_(2)Al_(5) phase is the main interfacial phase in Al/Fe composite sheets,and a smallamount of Fe_(4)Al_(13) phase is distributed close to the Al layer and dispersed in Fe_(2)Al_(5) phase.When w(Si)=1.48%is added to the iron side,the interfacial phases include Fe_(2)Al_(5) and asmall amount of Fe4Al13 with similar distribution to the Al/Fe interface where Si is not addedto the iron side.And Si-containing phases,i.e.,Fe_(3)Al_(2)Si_(3) and FeAl_(2)Si,are also formedand dispersed in the Fe_(2)Al_(5) phase close to the iron side.