退火温度对AgSnO_2Y_2O_3电接触材料组织与性能的影响

Effect of Annealing Temperature on Microstructures and Properties of AgSnO_2Y_2O_3 Electrical Contact Material

采用反应合成法制备了AgSnO2(8)Y2O3(2)电接触材料,并对其进行变形程度为20%的挤压,研究了不同退火温度对材料显微组织与性能的影响.结果表明,退火过程中氧化物颗粒易于在晶界偏聚,阻碍晶界的移动和位错的重排,从而抑制了再结晶的进行.随着退火温度的升高,材料的显微硬度不断下降,而导电率不断提高.材料的断裂方式为塑性断裂,变形主要在Ag基体上进行,氧化物颗粒可起到阻碍变形、强化材料的作用.在直流负载条件下,AgSnO2(8)Y2O3(2)材料表现出边缘优先烧蚀的特性.

AgSnO2( 8) Y2O3( 2) electrical contact material is prepared by reactive synthesis and cold extrusion with deformation of 20%. Effects of different annealing temperatures on microstructure and properties of the composite are investigated in present paper. The results show that during the annealing process,the oxide particles tend to segregate on the grain boundaries,which impede the removal of the boundaries and the rearrangement of dislocations and inhibit the recrystallization. With the annealing temperature increasing,the micro-hardness continuously decreases,while the conductivity increases constantly. The fracture mode of the composite is typical plastic fracture and the deformation mainly occurs in the Ag matrix. The oxide particles can impede the deformation and reinforce the material. Under DC load condition,arcing ablation of AgSnO2( 8) Y2O3( 2) material occurs at the brim of contact.