Abstract In this study, magnetron sputtering Y2O3 layer has been used as the nucleating agent at tungsten/reduced activation steel interface for solving the bonding difficulty between tungsten and reduced activation steels owing to the formation of FeW phase and the huge residual stress at tungsten/reduced activation steel interface fabricated by laser melting deposition. Moreover, SEM, EBSD and nanoscratch methods were applied to study the interfacial microstructure and mechanical properties of tungsten/reduced activation steel interface for exploring the action mechanism of Y2O3 in solidification and nucleation processes of molten pool. The results showed that Y2O3 as the nucleating agent could considerably promote FeW phase nucleation. With the increase in thickness of Y2O3 layer, mutual diffusion of W and Fe was decreased consequently, making the distribution of precipitated FeW phase more dispersed to effectively inhibit the formation of cracks caused by coarse FeW phase precipitation. It was also proved that the bonding strength of interface increased with the increase of the thickness of magnetron sputtering Y2O3 layer, which relieved the cracking phenomenon in the heterogeneous interface of tungsten/reduced activation steel.

中文翻译：

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磁控溅射添加Y2O3激光熔融沉积钨/还原活化钢异质界面结合强度优化机理

摘要 本研究采用磁控溅射 Y2O3 层作为钨/还原活化钢界面的成核剂，以解决钨与还原活化钢之间由于形成 FeW 相和钨/还原活化钢处巨大的残余应力而导致的结合困难。通过激光熔化沉积制造的活化钢界面。此外，应用SEM、EBSD和纳米划痕方法研究了钨/还原活化钢界面的界面微观结构和力学性能，以探索Y2O3在熔池凝固和形核过程中的作用机制。结果表明，Y2O3 作为成核剂可以显着促进 FeW 相成核。随着 Y2O3 层厚度的增加，W 和 Fe 的相互扩散随之减少，使析出的FeW相分布更加分散，有效抑制粗FeW相析出引起裂纹的形成。也证明了界面结合强度随着磁控溅射Y2O3层厚度的增加而增加，缓解了钨/还原活化钢异质界面的开裂现象。