Effect of ZrO(2) Nanomaterials on Wettability and Interfacial Characteristics of Al-19Cu-11Si-2Sn Filler Metal for Low Temperature Al to Cu Dissimilar Brazing

Dissimilar Al 3003 and Cu tubular components were successfully brazed without interface cracking using ZrO(2) nanomaterials reinforced with Al-19Cu-11Si-2Sn filler. The filler was initially cast using an induction furnace and processed into ring form for brazing. Al-19Cu-11Si-2Sn filler with coarse CuAl(2) and Si phases (43 and 20 μm) were refined to 8 and 4 μm, respectively, after the addition of 0.1 wt. % ZrO(2) and shows significant improvement in the mechanical properties. ZrO(2) nanomaterials’ induced diffusion controlled growth mechanism is found be the responsible for the refinement of CuAl(2) intermetallic and Si particles. The wettability of Al-19Cu-11Si-2Sn-0.1ZrO(2) increased to 78.17% on Cu side and 93.19% on the Al side compared from 74.8% and 89.9%, respectively. Increase in the yield strength, ultimate tensile strength, and percentage elongation were noted for the brazed joints. Microstructure of induction brazed joint with 40 kW for 6 seconds using Al-19Cu-11Si-2Sn-0.1ZrO(2) filler shows thin interfacial CuAl(2) intermetallic compound along the copper side and inter-diffusion region along the aluminum side and their respective mechanism is discussed. The tensile strength of the joints increased with increasing the nanomaterials addition and shows a base metal fracture. Analysis of fractured samples shows the effectiveness of ZrO(2) reinforced filler in crack propagation through the filler.