Effect of ultrasonic transmission rate on microstructure and properties of the ultrasonic-assisted brazing of Cu to alumina

Abstract

Fluxless brazing of bare alumina with Cu was conducted with an ultrasonic-assisted brazing technique by a Zn-14wt.%Al filler. The shear strength of Cu/alumina joints (84MPa) exhibited 27% larger than the alumina/Cu joints (66MPa) due to different intermetallic phases and their morphologies formed in the seam under the same parameters, which are probably attributed to the transmission rate of ultrasonic energy varying with density of the ultrasonic horn-contacted materials. Overgrowth of stalactite-like CuZn contributes to better thermal dissipation of the ultrasonic-assisted brazed Cu/alumina joints.

Ultrasonic-Assisted Semi-Solid Forming Method and Microstructure Evolution of Aluminum/Copper Brazed Joints

“…Zn-Al alloy is a promising brazing filler alloy for Al/Cu brazing [6][7][8][9]. The main advantage of the filler metal is that zinc metal and Cu and Al metal all had a very good solubility, which form good metallurgical combination easily, and the same time the Zn-Al alloy has good toughness and corrosion resistance.…”

Kinetics of Ultrasonic and Current Coupling-Enhanced Dissolution of Copper in Liquid Tin

“…8,9 Because of these advantages, ultrasound-assisted soldering is often used in connecting dissimilar materials, ceramics, and composite materials. [10][11][12][13] The compound field, which gives full play to the advantages of a single field and can compensate for their deficiencies, refers to the combination of two or more energies with completely different physical properties and conversion mechanisms that act on the same welding area. In the research of ultrasonic and current-coupling welding, Parkhimovich et al 14 introduced ultrasonic vibration in resistance spot welding to reduce the occurrence of nugget defects in hot-rolled steel welding.…”