In this paper, we present the development of micrometric and nanometric Ni + 10% Cr7C3 composite clad on ASTM A743 grade CA6NM hydroturbine steel through microwave irradiation. The microstructure of micrometric clad exhibited blade and rod-like structure of carbides embedded in γ (Ni, Fe) solid solution, while nanometric clad leads to the evolution of petal-like structure of carbides. The developed nanometric clad shows uniform microstructural features with a low level of carbide decomposition. As a result, the average nanohardness and fracture toughness of nanometric clad improved by 38.11% and 8%, respectively, compared to the micrometric clad. Clads have porosity of the order of 1.1% and 0.81% for micrometric and nanometric clad, respectively.

中文翻译：

---

微米级和纳米级 Ni + 10% Cr7C3 复合微波包层的显微结构和机械性能

在本文中，我们介绍了通过微波辐射在 ASTM A743 级 CA6NM 水轮机钢上开发微米级和纳米级 Ni + 10% Cr7C3 复合材料包层。微米包层的微观结构表现出嵌入γ（Ni，Fe）固溶体中的碳化物叶片和棒状结构，而纳米包层导致碳化物花瓣状结构的演变。开发的纳米包层显示出均匀的微观结构特征，碳化物分解水平较低。结果，与微米复合材料相比，纳米复合材料的平均纳米硬度和断裂韧性分别提高了 38.11% 和 8%。对于微米和纳米包层，包层的孔隙率分别为 1.1% 和 0.81%。