Grain-size insensitive work-hardening behavior of Ag microwires

In this study, the work-hardening behavior of Ag microwires with different grain sizes has been investigated, and the results show that the work-hardening rate of Ag microwires does not decrease with the increase of grain size, suggesting that the work-hardening capacity of Ag microwires is insensitive to grain size. Moreover, the microstructure evolution of the samples before and after tensile tests has been characterized using scanning electron microscope-backscattered electron (SEM-BSE), electron backscattered diffraction (EBSD) and transmission electron microscope (TEM). As a typical low stacking faults energy (SFE) material, stacking faults and twins are particularly easy to form in Ag microwires. Abundant stacking faults and twins, as well as minor lattice orientation adjustment in Ag microwires were observed and confirmed to play key roles on their grain-size insensitive work-hardening capacity. The current study provides insights for manufacturing Ag microwires for bonding process and other microelectronics applications.