MgO/Cu composites with different MgO contents were prepared by spark plasma sintering（SPS）with nano MgO particles as reinforcing phase.The effects of MgO particles content on arc erosion resistance of MgO/Cu composites were emphatically investigated

of which the arc erosion resistance mechanism was analyzed.Experimental results reveal that the arc erosion resistance of MgO/Cu composites is enhanced with the increase of volume fraction of MgO particles.When volume fraction of MgO particles is 5%

the total mass loss and arc energy of MgO/Cu composites reach the minimum value.The analysis indicates that MgO particles with high melting point is contributed to enhancing the mechanical properties and arc erosion resistance of MgO/Cu composites.During the process of arc erosion

the existence of MgO particles with high melting point can improve the molten pool viscosity of liquid copper matrix and reduce arc splashing

thus improving the arc erosion resistance of MgO/Cu composites.