面向低频大电流通断控制的低压开关设备性能完全依赖于银基电触头材料的性能，但银基电触头材料面临环保性差、极限抗拉强度低(< 200 MPa)、材料损失大(> 5%，质量分数)及服役寿命短(< 1 ´ 10⁴ cyc)等问题。与金属润湿性优良的层状MAX相在电接触过程中展现出优异的抗材料转移性能，但其A层原子与Ag基体互扩散引起的界面固溶劣化了Ag/MAX材料的导电性及接触可靠性。本工作旨在通过增强相的新成分筛选、新结构设计策略提升银基复合电触头材料的综合性能，围绕MAX相结构创新设计，结合机械球磨、喷雾造粒与真空热处理制备了表面负载纳米级Al₂O₃颗粒的大尺寸球状Ti₃AlC₂增强相，并将其与Ag基体复合。结果表明，球状微/纳复合结构增强相在提高Ag/Ti₃AlC₂材料组织均匀性同时促使Ag元素沿球状增强相晶界向其内部单向扩散，成功将Ag-Al互扩散行为限制在球状增强相内部，使Ag/Ti₃AlC₂材料的电阻率从5.462 μΩ•cm大幅降低至4.431 μΩ•cm。在复合过程中，球状增强相表面的纳米级Al₂O₃主要分布在Ag/Ti₃AlC₂界面处，部分纳米级Al₂O₃分散于基体中，与Ag单向扩散共同强化了界面结合，使Ag/Ti₃AlC₂复合材料的极限抗拉强度、界面Vikers硬度和界面纳米硬度分别提高至228.8 MPa、140.2 HV和3.261 GPa。在2 ´ 10⁴ cyc循环放电实验中，球状微/纳复合增强相和弥散分布的纳米级Al₂O₃共同作用，使熔池黏度增加，限制了液态Ag移动(材料损失仅1.7%)，提高了Ag/Ti₃AlC₂材料的抗电弧侵蚀性能。

Ag-based electric contact materials (ECMs) critically determine the performance of low-voltage switchgear for low-frequency and high-current control. However, these materials suffer from poor environmental friendliness, low tensile strength (< 200 MPa), high material loss (> 5%), and short service life (< 1 × 10⁴ cyc). To improve the comprehensive performance of Ag/Ti₃AlC₂ ECMs, this study designs a reinforcing phase with a novel composition and structure. For electrical contacting processes, the layered structure of MAX phases and their excellent wettability with metals ensure strong anti-material transfer performance of Ag/MAX composites. However, the interdiffusion between the A-layer atoms of MAX phases and the Ag matrix leads to interfacial solid-solution behavior that deteriorates the electrical conductivity and electrical contact reliability. To create an innovative design of the morphology and structure of MAX phases, this study combines mechanical ball milling, spray granulation, and vacuum heat treatment to prepare large-sized spherical Ti₃AlC₂-reinforcing phase powders with surface-loaded nano-Al₂O₃ particles that are subsequently combined with the Ag matrix. The spherical micro- and nano-composite structured reinforcing phase is found to improve the microstructure uniformity of the Ag/Ti₃AlC₂ material, promote unidirectional diffusion of Ag along the grain boundaries of the spherical reinforcing phase into its interior, and restrict the Ag-Al interdiffusion behavior within the reinforcing phase. Consequently, the resistivity reduced from 5.462 to 4.431 μΩ·cm. The nano-Al₂O₃ particles on the surface of the spherical reinforcing phase are mainly distributed at the Ag/Ti₃AlC₂ interface; however, some are detached and dispersed through the matrix. The unidirectional Ag diffusion and distribution of nano-Al₂O₃ particles collectively enhance the bonding quality of the composite interface, thereby increasing the tensile strength (228.8 MPa), interface surface hardness (140.2 HV), and interfacial nanohardness (3.261 GPa). During 2 × 10⁴ cyc of arc discharging, the microsized spherical Ti₃AlC₂ reinforcing phase and nanosized Al₂O₃ particles synergistically increase the viscosity of the molten pool at high temperatures caused by electric arc discharging, effectively restricting the movement of liquid Ag, diminishing the material loss to 1.7%, and thus improving the antiarc erosion performance of Ag/Ti₃AlC₂ composites. This work provides research ideas and technical references for the performance improvement of Ag-based ECMs.