Abstract To enhance the strength of iron-based alloys, a novel vanadium-vanadium carbide/iron (V–V8C7/Fe) core-shell rod-reinforced iron-based composite is designed and prepared via a two-step in-situ reaction at 1150 °C × 5 min +1100 °C × (4, 6, 8, 10 h). The V–V8C7/Fe core-shell rod consists of a ductile V-core and a gradient-structured V8C7/Fe-shell. The phases of the composite are V, V2C, V8C7, α-Fe, and P-rich phases. When the ratio (K) of the volume of V8C7/Fe-shell to the volume of the V-core is approximately 54, the comprehensive mechanical properties of the composite are optimal. The maximum hardness, maximum compressive strength and strain are about 1296 HV0.2, 1804 MPa and 13.9%, respectively. The high strength and high toughness of the composites are mainly attributed to the synergistic effect between the high toughness of the metal V-core and the gradient-distribution structure of the V8C7/Fe-shell layer.

中文翻译：

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两步原位反应制备的V-V8C7/Fe核壳棒增强铁基复合材料的显微组织和压缩性能

摘要 为了提高铁基合金的强度，通过两步原位反应设计并制备了一种新型钒-碳化钒/铁（V-V8C7/Fe）核-壳棒-增强铁基复合材料。 1150 °C × 5 分钟 +1100 °C ×（4、6、8、10 小时）。V-V8C7/Fe 核壳棒由延展性 V 型核和梯度结构的 V8C7/Fe 壳组成。复合材料的相是 V、V2C、V8C7、α-Fe 和富 P 相。当V8C7/Fe-shell的体积与V-core的体积之比(K)约为54时，复合材料的综合力学性能最佳。最大硬度、最大抗压强度和应变分别约为 1296 HV0.2、1804 MPa 和 13.9%。