Accessible Requires Authentication Published by De Gruyter February 23, 2021

Effect of Al–Si alloy coating on interfacial reactions and tensile strength in Ti/Al dissimilar brazing joints

Zhipeng Ma, Mingxuan Zhang, Leijun Li, Fafeng Xia and Zhiwu Xu

Abstract

We used ultrasonic-assisted brazing to join Al-Si-coated Ti alloys and Al alloys with a Zn-Al-Si filler metal. At the interface between the Ti alloy and Al-0.1Si alloy coating, a block TiAl3 phase formed. In contrast, for the Al-5Si alloy coating, the interfacial reaction layer of the joint consisted of a block Ti(Al,Si)3 phase and needle-like Ti7Al5Si12 phase. Finally, a granular Ti7Al5Si12 phase was formed at the joint interface for the Al-12Si alloy coating. The tensile strength of the joints formed with the Al-0.1Si and Al-12Si alloy coatings was only 160 -185 MPa, and cracks propagated mainly through the reaction layer. The tensile strength of the joints formed with the Al-5Si alloy coating ranged from 210 to 215 MPa, and cracks appeared entirely within the coating, subsequently expanding along the coating and ultimately resulting in failure of the joint.

Published Online: 2021-02-23
Published in Print: 2020-12-01

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