The Effect of Soaking Time on Mechanical Properties of Roll-Bonded AA3003 and AA4045 Used for Heat Exchangers

Due to the rising need for energy saving, high-performing automotive heat exchangers, demand has significantly grown in recent years. As a result, effective fin-tube exchangers are becoming more popular. These tubes typically made by rolling flat strips of AA3003 aluminum alloys that have either one or both sides coated with AA4xxx alloys. The type alloy is used as core, which then covered AA4045 AA4343, melts during brazing process adhere fins tubes. To maintain optimal size and distribution manganese (Mn)-containing precipitates, preheating parameters carefully controlled. Then, longer soaking times higher temperatures result larger cause final product exhibit poor mechanical properties. Therefore, it crucial optimize different manufacturing steps, such homogenization, time, order achieve high quality product. Studies on impact homogenization temperature time microstructure AA3xxx been conducted. However, there little research (reheating) cladded Hence, effects isothermal properties were investigated this work. Optical microscopy (OM) scanning electron (SEM) characterize identify intermetallic phases. terms grain structure at various was characterized backscattered diffraction (EBSD). After hot-rolling cold-rolling as-received material, large particles (mainly form Chinese script morphology consisting Fe-Mn-Si) broken into smaller an increased Fe, Mn, Si content, indicating formation α-Al(Fe,Mn)Si phase. α-Al(Mn,Fe)Si found be dominant dispersoid precipitate modified core. Coarsening Al(Mn,Fe)Si dispersoids 505 °C only observed 45 h time. hardness trend similar after cold working, annealing, exception increase latter possibly due strain hardening (from cold-rolling).