Interfacial Reaction and Wettability of 72Ag-28Cu Braze on CP-Ti Substrate Using Infrared Heating

Microstructure and Interfacial Reactions During Vacuum Brazing of Stainless Steel to Titanium Using Ag-28 pct Cu Alloy

“…The formation of the Cu 4 Ti 3 phase (layer 5) in the SS/Ti BZ was also reported in other investigations. [12,13,20,[34][35][36] However, contrary to the present observations, Shiue et al [19] and Shafiei et al [20] reported the formation of the Cu 4 Ti phase in the BZ, whereas they did not report the formation of Cu 3 Ti 2 phase which formed conspicuously in the present study. Andrieux et al [40] in an experimental investigation on the phase stability study on the Cu-Ti system showed that the Cu 3 Ti 2 phase is stable and can form by solid state reaction in a temperature range of 1063 K to 1133 K (790 C to 860 C).…”

“…Formation of such two-phase regions on the Ti-side is a commonly observed phenomenon during the brazing of Ti with Ag-based alloys. [10,12,14,16,19] Recently, the formation of a-Ti + CuTi 2 eutectoid due to interfacial reaction of Ti with Ag-28Cu eutectic alloy at 1123 K (850 C) was also confirmed by Shiue et al using TEM analysis. [19] The present authors showed recently, that the two phases in the a-Ti + (Cu,Ag)Ti 2 eutectoid layer, formed during brazing of SS to Ti with an Ag-Cu-based alloy at 1203 K (930 C), bear an orientation relationship.…”

“…[10,12,14,16,19] Recently, the formation of a-Ti + CuTi 2 eutectoid due to interfacial reaction of Ti with Ag-28Cu eutectic alloy at 1123 K (850 C) was also confirmed by Shiue et al using TEM analysis. [19] The present authors showed recently, that the two phases in the a-Ti + (Cu,Ag)Ti 2 eutectoid layer, formed during brazing of SS to Ti with an Ag-Cu-based alloy at 1203 K (930 C), bear an orientation relationship. [10] In spite of being the major element in the braze alloy, Ag did not diffuse much into the Ti base material through the BZ/Ti interface, which is also evident from the X-ray maps of Ti and Cu in Figure 2.…”

“…[12,13,20,34,35] This phase also formed in the interaction zone during the solid-liquid reaction between Ti and Ag-Cu alloys [19,36] and solid-solid reactive diffusion between Ti and Cu. [29] Laik et al [29] demonstrated that during the reactive diffusion of Cu and Ti, CuTi is the first one to form in the diffusion zone, using the ''effective heat of formation model.''…”

“…[11][12][13][14][15][16][17][18] The development of a suitable brazing technique essentially incorporates an in-depth understanding of the interfacial chemical reactions and identifying the mechanisms of these reactions, which can be used to optimize the bonding conditions, and hence achieve desirable properties of the joints. Recently, Shiue et al [19] have demonstrated the formation of layers of intermetallic compounds during reactive wetting of Ag-28Cu braze alloy with Ti substrate. Formation of such layered microstructure, during the brazing of stainless steel to titanium using Ag-Cu alloys in the temperature range of 1075 K to 1223 K (800 C to 950 C), was reported by Shafiei et al [20] Similar investigations on brazing of Ti and steel using Ag-Cubased alloys were also reported by Yue et al [12] and Elrefaey and Tillmann.…”