Inicio  /  Applied Sciences  /  Vol: 8 Núm: 6 Par: June (2018)  /  Artículo
ARTÍCULO
TITULO

Self-Powered Fast Brazing of Ti-6Al-4V Using Ni/Al Reactive Multilayer Films

Denzel Bridges    
Christopher Rouleau    
Zachary Gosser    
Cary Smith    
Zhili Zhang    
Kunlun Hong    
Jinquan Cheng    
Yoseph Bar-Cohen and Anming Hu    

Resumen

Self-powered brazing of Ti-6Al-4V was performed using Ni/Al reactive multilayer films (RMFs) as self-propagated heat resources. BAlSi-4 was first coated on Ti-6Al-4V by plasma welding, then alternating layers of Ni and Al were successfully deposited on BAlSi-4 up to 32.9 µm thick with e-beam deposition. The joint microstructure was investigated and the AlNi and Ni5Al3 phases were identified in the RMF. The cause for the two phases was determined to be differences in the diffusivity of Ni and Al, ultrafast brazing time, and faster cooling at the interface between brazing filler metal and the RMF. The maximum temperature of 683 °C was reached in the brazed joint, with a total RMF thickness of 135 µm, which is more than sufficient to melt the BAlSi-4 brazing material. The maximum bonding strength obtained was 10.6 MPa, with a self-power brazing procedure conducted in a minute. It is possible to further improve the bonding strength by using more ductile RMFs and/or modifying the bonding interface configuration.