ZrC-SiC ceramic and TC4 alloy were brazed using AgCuTi alloy. The microstructure and mechanical property of the joints obtained at different brazing parameters were investigated and the reaction mechanism was analyzed. The results indicated that the Ti from the AgCuTi and TC4 reacted with the ZrC in the ceramic to form different shaped TiC crystals adjacent to the ZrC-SiC ceramic. With the increase of brazing temperature or extending of holding time, the dissolution of TC4 became vigorous and much Ti dissolved into the braze alloy. As a result, Ti reacted with the Cu from AgCuTi alloy to form a series of Cu-Ti compounds in the brazing seam due to the strong affinity between Cu and Ti. The Cu-Ti compounds made the hardness and brittleness of brazing seam increase, which deteriorated the property of the brazed joint. The maximum shear strength was 39 MPa obtained at 810 °C for 5 min.

Interfacial microstructure and mechanical property of ZrC-SiC ceramic and Ti6Al4V joint brazed with AgCuTi alloy

Brazing ZrO2 ceramic and TC4 alloy by novel WB reinforced Ag-Cu composite filler: Microstructure and properties

Control interfacial microstructure and improve mechanical properties of TC4-SiO2f/SiO2 joint by AgCuTi with Cu foam as interlayer

Interfacial microstructure and mechanical properties of zirconia ceramic and niobium joints vacuum brazed with two Ag-based active filler metals

ZrC-SiC ceramic and TC4 alloy were successfully brazed using a self-prepared Ti-15Cu-15Ni filler. The microstructure and mechanical property of the joints obtained at different brazing temperatures were investigated. The results indicated that Ti from the Ti-15Cu-15Ni and the TC4 reacted with the ZrC-SiC to form TiC phase adjacent to the ZrC-SiC ceramic. In the brazing seam, Ti2(Ni, Cu) intermetallic compounds zone (IMCs Zone), Hypoeutectic Zone and Hypereutectoid Zone formed. The brazing temperature affected the dissolution of TC4 into the braze filler significantly, and then determined the microstructure of the joint. The formation of α-Ti in the brazing seam could decrease the hardness and the brittleness of the brazing seam, which was beneficial to the property of the brazed joint. The joint strength reached a maximum value of 43 MPa when the joint was brazed at 970 °C and cracks propagated in the ZrC-SiC substrate near the brazing seam.

Microstructure evolution and mechanical property of ZrC-SiC/Ti6Al4V joints brazed using Ti-15Cu-15Ni filler

Reliable brazing of ZrO 2 ceramic to TC4 alloy is crucial for the wide applications in aerospace industries and biomedical devices. However, the brazing mechanism of ZrO 2 ceramic has not been investigated systemically compared to Al 2 O 3 and Si 3 N 4 ceramics. The nature of the reaction products adjacent to ZrO 2 ceramic still remains somewhat elusive. In this study, ZrO 2 ceramic and TC4 alloy was successfully brazed with inactive AgCu filler metal. The interfacial microstructure of the joints was characterized by scanning electron microscope (SEM), X-ray diffraction (XRD) and transmission electron microscopy (TEM). The effect of brazing temperature on the microstructure and mechanical properties of the joints were investigated in details. The results revealed that Cu 3 Ti 3 O+TiO layers were formed adjacent to ZrO 2 ceramic while Ti–Cu IMCs layers were formed at TC4 substrate. With increasing brazing temperature, the thickness of Cu 3 Ti 3 O+TiO layers and Ti–Cu IMCs layers increased obviously. The hardness and elastic modulus of reaction phases were characterized by nano-indentation to reveal the plastic deformability. The highest shear strength of 52.2 MPa was achieved when brazed at 870 °C for 10 min.

Jiaqi Liu

Papers

Interfacial reaction behavior and mechanical characterization of ZrO2/TC4 joint brazed by Ag–Cu filler metal

Relationship between microstructure and mechanical properties of TiAl/Ti2AlNb joint brazed using Ti-27Co eutectic filler metal