摘要
以镍基合金和铝为原料,利用激光熔覆技术在低碳钢表面反应合成Ni-Al金属间化合物覆层。采用SEM,EDX,TEM和XRD等表征手段对试样的组织和相结构进行分析。结果表明:激光熔覆镍基合金与铝反应合金覆层由β-Ni Al和γ′-Ni3Al两相构成,两相中均固溶有一定量Fe,Si元素。β-Ni Al相含量较多,为细小、均匀、交错分布的树枝晶,Ni,Al间的反应放热使树枝晶呈现等轴化趋势;γ′-Ni3Al相含量较少,呈连续网状分布于β-Ni Al树枝晶周围,这种结构有利于降低覆层脆性。在1.5kW功率下,激光熔覆镍基合金及铝反应合成的β-Ni Al和γ′-Ni3Al两相合金覆层致密,有少量气孔但无裂纹现象,覆层与基体实现完全冶金结合。
Ni-Al intermetallic compound coatings were prepared on mild steel substrate by laser-cladding synthesize with mixed powders of Ni-based alloy and Al.The coatings microstructure and phase constitution were studied with SEM,EDX,TEM and XRD.The results show that the two-phase microstructure of the coating consists mainly of β-NiAl and γ′-Ni 3Al,with a certain amount of Fe and Si are retained in both solution.β-NiAl are uniformity and staggered fine dendrites surrounded continuously by γ′-Ni 3Al,which is beneficial to reduce the coating brittleness.Compact coats jointed metallurgically with the steel are obtained on 1.5kW powers,a few pores but no cracks are also found in the claddings.
出处
《材料工程》
EI
CAS
CSCD
北大核心
2010年第3期29-33,37,共6页
Journal of Materials Engineering
基金
安徽省国际科技合作计划资助项目(08080703020)
