Infrared Brazed Joints of Ti<sub>50</sub>Ni<sub>50</sub> Shape Memory Alloy and Ti-15-3 Alloy Using Two Ag-Based Fillers
oleh: Chieh Lin, Ren-Kae Shiue, Shyi-Kaan Wu, Tsung-En Yang
| Format: | Article |
|---|---|
| Diterbitkan: | MDPI AG 2019-05-01 |
Deskripsi
The wettability, microstructures, and bonding strength of infrared brazing Ti-15-3 and Ti<sub>50</sub>Ni<sub>50</sub> shape memory alloy using 72Ag-28Cu (wt.%) and 68.8Ag-26.7Cu-4.5Ti (wt.%) filler metals have been investigated. Only Ticusil<sup>®</sup> active braze readily wets both Ti<sub>50</sub>Ni<sub>50</sub> and Ti-15-3 substrates. Wetting of eutectic 72Ag-28Cu melt on Ti<sub>50</sub>Ni<sub>50</sub> base metal is greatly ameliorated by adding 4.5 wt.% Ti into the alloy. The brazed Ti-15-3/BAg-8/Ti<sub>50</sub>Ni<sub>50</sub> joint consists of Cu-Ti intermetallics in the Ag-rich matrix. The formation of interfacial Cu(Ti,V) and (Cu<sub>x</sub>Ni<sub>1−x</sub>)<sub>2</sub>Ti intermetallics next to Ti-15-3 and Ti<sub>50</sub>Ni<sub>50</sub> substrates, respectively, is attributed to the wetting of both substrates. The brazed Ti-15-3/Ticusil<sup>®</sup>/Ti<sub>50</sub>Ni<sub>50</sub> joint shows a vigorous reaction, which results in the formation of a large amount of Ti<sub>2</sub>Ni intermetallics in the joint. The maximum joint strengths using BAg-8 and Ticusil<sup>®</sup> filler metals are 197 MPa and 230 MPa, respectively.