钛合金因密度小、比强度高、耐腐蚀等性能，在国防工业领域备受青睐，已广泛应用于坦克装甲车、火炮等兵器设备。 但因其表面硬度低、耐磨性差，限制了钛合金的使用范围。 本研究以 TC4 钛合金板材为研究对象，对其表面实施离子渗氮处理，旨在提高合金的表面硬度并探究其在渗氮后组织结构和性能变化。 利用 X 射线衍射仪和扫描电子显微镜对离子渗氮后的组织进行观察，通过维氏显微硬度仪测定试样的硬度，分析离子渗氮工艺对组织、结构和性能的影响。 结果表明，当渗氮工艺参数为 450 ℃、保温 8h 时，TC4 钛合金试样呈现金黄色，其表面形成的渗氮层主要含有高硬度的 TiN 相，使得 TC4 钛合金在平面和厚度两个方向的表面硬度都得到了提升，且厚度方向上的硬度提升效果更为显著。

Titanium alloys, which are favoured by the national defense industry for their excellent properties, such as low density, high specific strength and corrosion resistance, are used in tanks, armored vehicles, artillery and other weapons and equipment. However, owing to their low surface hardness and poor wear resistance, the application range of titanium alloys is limited. On this basis, the surface of the TC4 titanium alloy sheet was treated by ion nitriding to improve the surface hardness of the alloy and to explore the changes in microstructure and properties after nitriding. The microstructure after ion nitriding was observed via X-ray diffraction and scanning electron microscopy. The hardness of each sample was measured via a Vickers microhardness tester, and the effects of the ion nitriding process on the microstructure, structure and properties were analysed. The results show that the surface of the TC4 titanium alloy sample is golden yellow after nitriding at 450 ℃ for 8 h. The nitriding layer formed on the surface mainly contains a TiN phase with high hardness, which improves the surface hardness of the TC4 titanium alloy in both the plane and thickness directions, and the effect of increasing hardness in the thickness direction is more significant.