CAJ | 학술논문

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-NiAl和γ′-Ni_3Al两相构成,两相中均固溶有一定量Fe,Si元素.β-NiAl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′-Ni_3Al相含量较少,呈连续网状分布于β-NiAl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-NiAl和γ′-Ni_3Al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.
이얼기합금화려위원료,이용격광용복기술재저탄강표면반응합성Ni-Al금속간화합물복층.채용SEM, EDX, TEM 화XRD등표정수단대시양적조직화상결구진행분석.결과표명:격광용복얼기합금여려반응합금복층유β-NiAl화γ′-Ni_3Al량상구성,량상중균고용유일정량Fe,Si원소.β-NiAl상함량교다,위세소、균균、교착분포적수지정, Ni,Al간적반응방열사수지정정현등축화추세;γ′-Ni_3Al상함량교소,정련속망상분포우β-NiAl수지정주위,저충결구유리우강저복층취성.재1.5kW공솔하,격광용복얼기합금급려반응합성적β-NiAl화γ′-Ni_3Al량상합금복층치밀,유소량기공단무렬문현상,복층여기체실현완전야금결합.
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.