Abstract
Abstract To meet the requirements of automatic production, a new type of green BAl88Si cored solder was developed. The lap brazing experiments were carried out with copper and aluminum as brazing substrates. The microstructure, phase composition, and corrosion behavior of solder joint interface were studied by field emission scanning electron microscopy, energy dispersive spectroscopy, transmission electron microscopy, electron backscattering diffraction, tensile testing machine, and electrochemical workstation. The results show that the brazing joint of Cu/BAl88Si/Al is metallurgical bonding, and the brazing joint of Cu/BAl88Si/Al is composed of Cu9Al4, CuAl2, a-Al, (CuAl2 + a-Al + Si) ternary eutectic. In addition, there is no obvious preference for each grain in the brazing joint, and there are S texture {123}<634>, Copper texture {112}<111>, and Brass texture {110}<112>. The interface of Cu9Al4/CuAl2 is a non-coherent crystal plane and does not have good lattice matching. The average particle size of CuAl2 is 11.95 µm and that of Al is 28.3 µm. However, the kernel average misorientation (KAM) value at the brazed joint interface is obviously higher than that at the brazed joint interface copper, so the defect density at the brazed joint interface aluminum is higher than that at the brazed joint interface copper. At the same time, due to poor corrosion resistance at the interface on the aluminum side of the brazed joint, serious corrosion spots and corrosion cracks occur at the same time, which leads to the shear performance of the brazed joint decreasing by about 75% after salt spray test for 240 h.
Highlights
Copper is widely used in the manufacture of thermal components in refrigeration fields such as air conditioners and refrigerators, aerospace, and power industries because of its excellent thermal conductivity and electrical conductivity
Two dense intermetallic compound layers were formed at the brazing interface near Cu, with a thickness of 7–15 μm
The intermetallic compounds away from the copper interface of brazed joints tend to grow in brazed joints
Summary
Copper is widely used in the manufacture of thermal components in refrigeration fields such as air conditioners and refrigerators, aerospace, and power industries because of its excellent thermal conductivity and electrical conductivity. There are a series of problems in pressure welding, such as high welding cost, complex process, poor adaptability to complex welding parts, long production cycle, etc., which restrict the application of pressure welding in different copper and aluminum welding [15,16]. Brazing is widely used in the connection of two different metals, copper and aluminum, resulting in a joint with high strength and good airtightness [17,18]. In the traditional brazing process, the composite application form of brazing filler metal and brazing flux usually adopts the way of placing brazing filler metal on brazing parent metal in advance or sticking brazing flux on solid brazing filler metal This method greatly increases the pre-welding process and operation time and adds a variable during the brazing process, which affects the consistency and quality stability of welding. The innovative combination of lattice mismatch and KAM value at the brazing interface and corrosion behavior at the brazing interface are helpful to study corrosion protection of copper and aluminum brazed joints in the outdoor wet environment
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
