The Dependence of Microstructural Evolution and Corrosion Resistance of a Sandwich Multi-Layers Brazing Sheets on the Homogenization Annealing

Abstract

The influence of the microstructure on the corrosion susceptibility and mechanism of aluminum sheet was studied. The homogenization annealing treatment results in the segregation of copper on the surface of the re-solidified clad material and the increase of the diffusion depth of Si during brazing. The band of dense precipitates has a higher corrosion potential than clad and core material, and the high density particles in the diffusion zone (40 um<depth<70 um) are identified as α-Al(Fe-Mn)Si particles. Thus, the band of dense precipitates are catalytic sites for cathodic reduction reactions. Moreover, the effect of homogenization annealing treatment on the local electrochemical activity and corrosion properties are studied. The results indicate that the band of dense precipitates formed in the diffusion zone in the sample without homogenization annealing during brazing process, which improves the corrosion resistance of the material. Compared with sample with homogenization annealing at the same thickness, the time for the perforation during seawater acetic acid test of the sample without homogenization is longer than that of the homogenization annealed sample. INDEX TERMS Aluminum brazing sheet, microstructural characterization, Si diffusion, electrochemical characterization, corrosion behavior.

The Effect of Microstructural Evolution on the Brazeability of Two-Layer Al Sheets

“…In this paper, a method for testing the fluidity of the clad material by Jiangsu Alcha Aluminum Company Co., Ltd. was adopted [11]. The testing process for clad fluidity is shown in Table 3.…”

Evaluating the Mechanical and Tribological Properties of DLC Nanocoated Aluminium 5051 Using RF Sputtering

“…The XRD graph is presented in Figure 7. The sample is kept in an XRD machine and swept from 20 °to 90 °angles for analysis [28]. There are no other peaks other than carbon, and the detected carbon is in amorphous graphite without crystalline diamond form.…”

Evaluation of Prestrain Annealing Impact on Nanomaterial Sensitization

“…After brazing the affected area, Si concentration increases. During brazing in the diffusion zone, dense precipitates were formed, which improves the brazing sheet's corrosion resistance [20]. Li et al present the feasible test for aluminum alloy bridge deck based on the experimental study on wearability and corrosion resistance.…”

“…By using X-ray diffraction, carbides were found, by the TTP curves; OM, SEM-EDS, and TEM were also listed. Temperatures between 873 and 1073 K display a low sensitivity to intergranular attack in aged specimens [20]. Kosec et al find the austenite heatresistant stainless steel transformation kinetics which were discussed.…”