采用粉末冶金技术制备了Ni-5Al-xSi（x=0，1.5，3.0，4.5，质量分数/%）高温合金，并分别在1 000，1 100℃恒温氧化100 h，观察了合金表面氧化膜形貌，分析了其物相组成，研究了合金的高温抗氧化性能。结果表明：试验合金的高温抗氧化性能随着硅添加量的增加而提高，当硅质量分数达到3.0%以后，再增加硅对合金高温抗氧化性能的提高效果有限；未添加硅的合金表面氧化膜的主要成分是NiO，添加硅后氧化膜的组成除了NiO外，还有NiAl₂O₄和Al₂O₃，且氧化膜存在不同程度的剥落现象；当硅质量分数为4.5%时，试验合金的高温抗氧化性能最好。

Ni-5Al-xSi (x=0, 1.5, 3.0, 4.5, mass fraction/%) superalloys were prepared by powder metallurgy technique, and then isothermally oxidized at 1 000, 1 100℃ for 100 h. The morphology of oxide film on the alloy surface was observed and the phase composition was analyzed. The high temperature oxidation resistance of the alloys was studied. The results show that the high temperature oxidation resistance of the tested alloys increased with increasing silicon addition amount; when the mass fraction of silicon reached 3.0%, increasing silicon content had little effect on high temperature oxidation resistance improvement of the alloys. The oxide film on surface of the alloy without addition of silicon was mainly composed of NiO. After addition of silicon, the oxide film mainly consisted of NiO, NiAl₂O₄ and Al₂O₃, and showed spalling features at different degrees. When the mass fraction of silicon was 4.5%, the high temperature oxidation resistance of the tested alloy was the best.