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e processing mechanism of copper matrix composites is very complex, for the particle phase and lubricating phase are randomly distributed in the copper matrix phase, and the characteristics of the three phases are completely different. Aiming at understanding the chip formation and the influence of each phase of the material on the workpiece surface morphology, a single abrasive grain cutting experiment is carried out. Experiment results show that the cutting force increases with the increase in the cutting depth, but the increase amplitude is smaller. Extrusion of the abrasive particles causes plastic deformation of the copper matrix phase and brittle fracture of the particle phase and graphite phase. It results in the defects on the groove surface, such as pits, collapses and cracks, and holes. e brittle fracture of the graphite phase and the breaking and falling off of the particle phase block the plastic deformation of the copper alloy, which makes the copper alloy not forming ductile chips. e chip is mainly powdery. It shows that the brittle fracture is the main removal form of the brake pad material. e copper matrix phase on the surface of the groove produces obvious plastic deformation. e plastic deformation at the bottom is larger and has a certain degree of fibrosis appearing.

A low-profile composite isolator (CI) for the decoupling of broadband, high-density, dual-polarized cross-dipole arrays is introduced and investigated. The CI is composed of periodically resonant strips and a metallic wall, which are etched on both sides of a thin dielectric-slab and vertically placed above the ground plane. The collaboration between the strips and the wall empowers the CI's broadband operation performance characteristics with low profile (0.16 λ 0) and ultra-thin thickness (0.0045 λ 0). A two-element crossdipole array loaded with CI is fabricated and tested to verify its decoupling effect. The two ±45°dual-polarized cross-dipole elements with impedance bandwidth of 45% (ranging from 1.7 to 2.7 GHz) are built with centre-to-centre distance of 0.45 λ 0 (λ 0 corresponds to free space wavelength at 1.7 GHz). The measured results, in good agreement with the simulation values, indicated that, after loading CI, the array witnessed 10 dB co-polarized and 5 dB cross-polarized isolation improvements while maintaining stable radiation patterns over the entire operational band, without increasing the overall array height. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.