用声发射（AcousticEmission）方法及扫描电镜SEM／EDXA，对Co－40Cr合金在1000℃空气中20h恒温氧化后表面氧化膜的开裂和剥落进行了研究．并与该合金表面离子注入3×1016Y+／cm2和3×1017Y+／cm2后的氧化结果进行了比较．结果表明，离子注钇后极大地改善了合金表面氧化膜的抗开裂和抗剥落性能．此外，用声发射方法能够间接地测量出氧化膜／合金界面处“预存缺陷”（pre-existingdefects）的分布情况．离子注钇改善合金表面氧化膜的粘附性与注钇后减小了界面处“预存缺陷”的数目及平均大小有关． The surface oxide film cracking and exfoliation of Co-40Cr alloy were investigated by means of acoustic emission and scanning electron microscopy (SEM / EDXA) at 1000 ℃ for 20 h in air. The results were compared with those obtained by ion implantation of 3 × 1016Y + / cm2 and 3 × 1017Y + / cm2 on the surface of the alloy. The results show that ion implantation of yttrium greatly improves the anti-cracking and anti-spalling properties of the oxide film on the surface of the alloy. In addition, the distribution of “pre-existing defects” at the oxide film / alloy interface can be indirectly measured by the acoustic emission method. Ion-implanted yttrium improves the adhesion of the oxide film on the surface of the alloy and reduces the number of “pre-existing defects” and the average size at the interface after yttrium injection.