Investigation of ultrasound-assisted soldering of SiC ceramics by Zn-Al-In high-temperature solder

摘要

This work deals with the study of ultrasonic soldering of SiC ceramics by use of Zn-Al-In solder destined for higher application temperatures. The structure and properties of this soldering alloy were assessed. The Zn5Al1In solder consists of beta Zn matrix, where the beta Zn + alpha Al a (In) eutectics in the form of oblong and spherical clusters are non-uniformly distributed. The tensile strength of soldering alloy attained the value of 52 MPa. The soldered joint of SiC/Zn5Al1In/SiC was fabricated at the temperature of 420 degrees C at simultaneous acting of ultrasonic vibrations. The bond was formed owing to the formation of two new thin layers of Al + Si and Zn + C on the surface of SiC substrate. The average shear strength of SiC/Zn5Al1In/SiC joint attained 49 MPa. The fracture has occurred not only in the solder bulk but also in a close vicinity of SiC substrate. In this zone, similarly as on the fractured surface in the solder zone, the presence of In was identified, in which a considerable measure affected the resultant strength values.