Self-heating bonding of A5056 aluminum alloys using exothermic heat of combustion synthesis

• Published in: Materials & design Vol. 113; pp. 109 - 115
• Main Authors: Matsuda, Tomoki, Maruko, Takaaki, Ogura, Tomo, Sano, Tomokazu, Hirose, Akio
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 05.01.2017
• Subjects: Aluminum addition; Aluminum alloy; Combustion synthesis; Self-heating bonding; Tensile strength; Combustion synthesis; Self-heating bonding; Aluminum addition; Tensile strength; Aluminum alloy
• ISSN: 0264-1275; 1873-4197
• DOI: 10.1016/j.matdes.2016.10.017

A bonding process utilizing self-heating due to exothermic heat from the combustion synthesis of TiB2 was investigated for A5056 aluminum alloys. Aluminum particles were added to a Ti–B mixed powder to not only reduce the porosity, but also to produce composites between TiB2 and aluminum in the bonding layer. The bonding process using exothermic rather than external heat was successfully achieved by controlling aluminum addition, which significantly improved the joint tensile strength. The fracture surfaces showed the presence of aluminum oxide, while joint cross-sections showed that the bonding material and added aluminum filled pores of synthesized TiB2, which contributed to the decrease in the joint porosity. Both porosity and aluminum oxide content, dependent on aluminum addition, were correlated with the joint strength. Therefore, appropriate control of aluminum addition can be used to produce sound joints in self-heating bonding at lower temperatures. [Display omitted] •The improvement in tensile strength of self-heating bonded joint was successfully achieved by aluminum addition to Ti–B system.•Appropriate aluminum addition controls not only suppression of aluminum oxide and porosity, but also formation of metal-ceramic composites joints.•Duration of liquid phase of aluminum is responsible for the oxidation, revealing the possibility of low temperature bonding.