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以镍基高温合金GH586为基体材料,采用电镀Pt和固体粉末包埋渗铝的方法在其表面制备PtAl涂层。采用X射线衍射(XRD)、扫描电镜(SEM)对不同渗铝时间下PtAl涂层的高温氧化过程中各阶段的物相结构及微观组织变化进行表征及分析。研究表明,在高温氧化过程中,随着渗铝时间的增加,涂层中β-NiAl相转变为γ’-Ni_3Al相的几率越小,迅速生成Al_2O_3膜的时间越短,形成起扩散障作用的Cr、W等元素富集区的厚度越大,从而大大提高了镍基合金的抗氧化性。渗铝3 h的PtAl涂层具有最优的抗氧化性能,其氧化速率常数k_(3h)=1.17×10~(-6)。
Based on the nickel-based superalloy GH586, PtAl coating was prepared on the surface of the superalloy GH586. XRD and SEM were used to characterize and analyze the phase structure and microstructure of the PtAl coatings during the high temperature oxidation. The results show that the rate of β-NiAl phase transformation into γ’-Ni_3Al phase decreases with the increase of aluminizing time, and the faster the Al 2 O 3 film formation, the faster the diffusion barrier effect Of Cr, W and other elements enrichment zone the greater the thickness, thereby greatly improving the oxidation resistance of nickel-based alloys. The PtAl coating with 3 h of aluminizing has the best oxidation resistance, the oxidation rate constant k_ (3h) = 1.17 × 10 ~ (-6).