The pantograph-catenary system bears the crucial task of supplying electrical energy to high-speed trains. However, as train speeds continue to climb, irregularities in the contact wire exacerbate vibrations within the pantograph-catenary system, frequently triggering pantograph arcs. To delve deeper into the characteristics and erosion mechanisms of these arcs, this study employed high-speed cameras and photodiodes to precisely capture the evolution of arc morphology and fluctuations in arc intensity triggered by contact pair irregularities. By adjusting the current intensity, we further analyzed the impact of arc discharge on the friction and wear performance of carbon strips, as well as their current-carrying efficiency. The study found that when the current is sufficiently high, the arc column of the old arc, which forms when the contact pair separates, connects with the arc root of the new arc that is yet to make contact, leading to the formation of a continuous arc. Additionally, under the same current conditions, the arc intensity prior to contact between the tribo-pair is notably weaker than that at the moment of separation. Furthermore, parameters such as arc ignition rate, wear volume, and temperature all positively correlate with current intensity. Severe arc discharge not only deteriorates the electrical performance of the system, causing current distortion, but also exacerbates the instability of system operation. Abrupt changes in the friction coefficient can serve as a harbinger of intense arcs between the contact pair. Arc erosion causes severe damage to the current-carrying tribo-pairs, with ablation pits riddled with thermal cracks and pores, and leaving behind numerous molten copper particles, significantly increasing the wear volume. This study provides strong support for understanding the arc erosion process caused by contact wire irregularities and the mechanisms underlying abnormal wear of carbon strips.

The ceramic green bodies with different structures can be formed via binder micro-jetting and bonding additive manufacturing technology. However, the density, strength and surface quality of the sintered ceramic bodies are low. The nanozirconia suspension was used as a jet solution to substitute a conventional organic binder, and the effect of nanozirconia suspension jet amount on the properties of additive manufactured zirconia ceramics after sintering was investigated. When the nanozirconia suspension jet amount increases from 0 to 175%, the line shrinkage and surface roughness of sintered zirconia ceramics decrease significantly, and the reduction rates are 6%–8% and 57%, respectively, while the relative density, flexural strength and hardness increase considerably, and the increase rates are 18.1%, 124.0%, and 187.0%. The nano-sized zirconia particles can fill in the pores of the zirconia powder layer after introducing the nanozirconia suspension, thus improving the green density and the sintering quality of the zirconia ceramic. This provides an effective method for rapid manufacturing complex and compact ceramic parts.