Characterizing the Soldering Alloy Type Zn–Al–Cu and Study of Ultrasonic Soldering of Al7075/Cu Combination

Abstract

The aim of the research was to characterize the soldering alloy type Zn–Al–Cu and study the fluxless ultrasonic soldering of the combination of aluminum alloy type Al7075 with copper substrate. The Zn–Al–Cu solder is of the close-to-eutectic type with two phase transformations: the eutectic transformation at 378 °C and the eutectoid transformation at 285 °C. The solder microstructure is formed of a matrix composed of the solid solutions of aluminum (Al) and zinc (Zn) in which the copper phases CuZn4 and CuAl2 are precipitated. The shear strength of the soldering alloy type Zn5Al with copper addition reaches values from 167 to 187 MPa and it depends on the copper content in the solder. The bond with aluminum alloy type Al7075 is formed due to the solubility of Al in zinc solder at the formation of solid solution Al. Contrary to this observation, the bond with the copper substrate is in this case formed due to the interaction of zinc and aluminum with the copper substrate. Two new intermetallic phases, namely Al(Cu,Zn)2 and Cu3.2Zn0.7Al4.2, were formed. The average shear strength of Al7075/Zn5Al3Cu/Cu joints attained was 134.5 MPa. For comparison, the Cu/Zn5Al3Cu/Cu joint attained an average shear strength of 136.5 MPa.

Characterization of an Active Soldering Zn-Mg Alloy and the Study of Ultrasonic Soldering of SiC Ceramics with Copper Substrate

“…The authors of the study [14] were successful in joining SiC ceramics by application of ultrasonic soldering technology. Two types of Zn-based solders were applied--namely, the non-eutectic alloy type Zn5Al3Cu and the eutectic alloy type Zn5Al.…”

Investigation of microstructure evolution and mechanical properties of 2024 Al/Al2O3 ceramic joints

“…The acoustic cavitation and acoustic streaming [13,14] can break the oxide film of metals and make Sn-based solder spread out quickly on the surface of Al 2 O 3 ceramic. As an advanced process of joining ceramic, ultrasonic soldering process has been studied by many scholars [15][16][17][18]. Koleňák et al [18] successfully realised the ultrasonic soldering of AIN ceramics with Cu substrate using Sn-Ag-Ti solder.…”