Interfacial characteristics for brazing of aluminum matrix composites with Al-12Si filler metals
Journal
Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science
Journal Volume
28
Journal Issue
12
Pages
2673-2682
Date Issued
1997
Author(s)
Abstract
Discussions concerning the interfacial reactions and characterizations in brazing aluminum matrix composites are documented in this study. Joints of alumina particulate reinforced 6061 aluminum matrix composites were made using an Al-12 (\vt pet) Si filler metal by vacuum brazing. The resulted maximum bonding strengths were 75.4, 81.5, and 71.8 MPa for 10, 15, and 20 vol pet alumina reinforcement, respectively. The microstructural examinations revealed that the bonding strength was strictly related to the reinforced alumina particles and the reaction products presented at the joint interfaces. During brazing, Mg segregated at the joining interface and alumina/6061 Al interface. Further, reactions between alumina and 6061 Al matrix resulted in the formation of Mg-rich phases, such as MgAl2O4 and MgO, near the joining interface and the alumina reinforcement. The Si in the filler material penetrated into the metal matrix composites (MMCs) matrix and segregated at the alumina/6061 AI interfaces. This phenomenon can be confirmed by a joint between two alumina bulk specimens.
Type
journal article