Current-Carrying Fretting Wear Characteristics of Silver-Plated Copper Materials under High Current Conditions

The silver-plated copper tube was prepared by plating silver on surface of T2 copper tube by the chemical plating method. The room temperature current-carrying tangential fretting wear test in the cylinder/cylinder orthogonal point contact mode was conducted on the self-developed tangential fretting wear test equipment. The current-carrying fretting wear behavior of silver-plated copper samples under a current of 5 A and different normal loads (5, 10, 15 N) and displacement amplitudes (30, 50, 70, 100 μm) and its wear mechanism were studied. The results show that with the increase of displacement amplitude, the degree of current-carrying fretting wear of silver-plated copper samples decreased. With the increase of the number of cycles, the friction coefficient under different displacement amplitudes decreased first, then increased and finally tended to be stable, while the contact resistance showed the opposite trend. The friction coefficient in the stable stage under different displacement amplitudes had little difference. With the increase of load, the current-carrying fretting wear degree first increased and then decreased. When the load was 10 N, the wear degree was the largest, and at this time the effective contact area was relatively large, and the contact resistance was relatively small. With increasing load, the friction coefficient in the stable stage increased. The wear mechanism of silver-plated copper samples in the initial stage of wear was mainly adhesive wear and oxidation wear, and that in the middle and later stage of wear was abrasive wear, oxidation wear and delamination. The oxidation wear degree decreased with the increase of the number of cycles.