Hf和Y对Ni3AI/CrMoB合金氧化性能影响

研究了Hf和Y对Ni3Al-7.8Cr-4Mo-0.05B合金氧化性能的影响,测定了合金在1000和1100℃的恒温氧化动力学曲线,并通过XRD分析表面氧化膜结构,通过扫描电镜和能谱分析研究了氧化产物的微观组织与成分.结果表明:Hf和Y的加入大大提高合金的抗氧化性能,主要影响在于形成稳定性更好的HfO2.提高氧化膜与基体的粘结力,抑制了硫在氧化皮/基体界面的偏聚、改变氧化膜的形貌与组成、内氧化程度、扩散层深度等.

Effects Of Hafnium and Yttirium on the Oxidation-Resistence of Ni3A1/CrMoB Alloy

The effects Of Hf and Y on the oxidation resistance of Ni3Al-7.8Cr-4Mo-0.03B alloy were studied in the present paper.The isothermal oxidation kinetic curves of the alloy at 1000℃and 1100℃ were investigated.and the structure of oxidized surface was analyzed by X-ray diffraction.The research on the microstructure and composition of the oxides was conducted by means of a scanning electron microscope with EDAX unit and X-ray energy spectrometer.The results show that the addition of hafnium and yttrium significantly improves the oxidation resistance of this alloy.The positive effects are due to the formation of more stable oxide HfO2,which increase the adhesion strength between substrate and oxide layer,and meanwhile restrain the segregation of sulfur on the interface of oxidation scale and substrate.Besides these,the addition of hafnium and yttrium also change the morphology and composition of the oxides scale,the degree of inner oxidation,and the diffusion layer as well.