2004 Volume 22 Issue 4 Pages 580-586
Experiment was accomplished on the diffusion bonding of TiAl intermetallic compound to Ti-6Al-4V alloy and pure titanium and comparison was made on the tensile strength and the microstructure of the joints.
The common aspects between these two types of bonding are as follows: (1) The reaction layer of Ti3Al was formed at the bonding interface. (2) The tensile strength of the joint decreased with increasing the width of the reaction layer. (3) The scatter in the tensile strength was substantially large, which is mainly due to the properties and the shapes of the reaction layer of Ti3Al.
The points of difference between two bondings are as follows: (1) The optimal bonding temperature for the TiAl/Ti-6Al-4V was lower than that of the TiAl/Ti joint when the other conditions were kept identical. It is explained by the diffusion speed of Al atom to Ti alloy or pure Ti, which depends on the crystal system of Ti(α) and Ti-6Al-4V(α+β). (2) Kirkendall voids were observed at the bonding interface of the TiAl side on TiAl/Ti joints at 1223K, whereas no such voids were observed on TiAl/Ti-6Al-4V joints.