scholarly journals Vacuum Brazing of C/C Composite and TiAl Intermetallic Alloy Using BNi-2 Brazing Filler Metal

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1844
Author(s):  
Shengnan Li ◽  
Dong Du ◽  
Lei Zhang ◽  
Qingle Hao ◽  
Weimin Long
Keyword(s):  
Shear Strength ◽  
Intermetallic Compound ◽  
Filler Metal ◽  
Holding Time ◽  
Joint Shear Strength ◽  
Vacuum Brazing ◽  
Tial Intermetallic Compound ◽  
Brazed Joint ◽  
Temperature Shear ◽  
Perfect Interface

C/C composite was brazed to TiAl intermetallic compound using a commercial BNi-2 brazing filler metal under vacuum brazing condition. The brazing temperature was 1030~1150 °C and the holding time was 20 min. The joint interfacial microstructures and mechanical properties were studied, and the fracture behavior and joining mechanism were also investigated. The effect of brazing temperature on the joint shear strength was explored. The results showed that a perfect interface joint can be obtained by using BNi-2 to braze C/C and TiAl. During brazing, Ti, Cr, and other carbide forming elements diffused to C/C composite side, forming Cr3C2, Cr7C3, TiC, and other carbides, and realizing metallurgical joining between the brazing filler metal and C/C composite. The microstructure of the interface of C/C composite and TiAl intermetallic compound joint is as follows: TiAl alloy → TiAl + AlNi3 → AlNi2Ti → Ni(s, s) + Ti3Al + Ni3Si → Ni(s, s) + Ni3(Si, B) + CrB → Ni(s, s) + Ni3Si + TiCr2 → (Ti, Cr)C → C/C composite. When the holding time is fixed, with the increase of brazing temperature, the shear strength of the joint increases first and then decreases. The maximum average room temperature shear strength of the brazed joint was 11.62 MPa, while the brazing temperature was 1060 °C and the holding time was 20 min.

Effect of Ti Addition on Shear Strength of Brazing Diamond and Ag Based Filler Alloy

2009 ◽  
Vol 416 ◽  
pp. 264-268 ◽  
Author(s):  
Yan Chen ◽  
Hong Jun Xu ◽  
Yu Can Fu ◽  
Hong Hua Su
Keyword(s):  
Shear Strength ◽  
Filler Metal ◽  
Filler Alloy ◽  
Interface Zone ◽  
Vacuum Brazing ◽  
Interfacial Reaction Product ◽  
Single Crystal Diamond ◽  
Brazed Joint ◽  
Ti Content ◽  
Ti Addition

The shear strength samples of brazed single crystal diamond with the (72Ag–28Cu)–xTi (x=2, 4, 7wt.%) active filler metal were prepared, using vacuum brazing methods. Microstructure evolution of interfacial reaction product and shear strength of the brazed diamond and Ag based filler alloy were studied. The results show that there exits a layer of TiC on the surface diamond in different Ti additions, and the thickness of TiC layer increases with the increase of Ti addition. With the increase of Ti addition, the shear strength of the brazed joint decreases due to the increase of TiC layer thickness and amount of intermetallics. From the results, it was seen that mutual diffusion of C and Ti was effective on the morphology of the interface zone that affected the shear strength of the bonds. To achieve a reliable brazed joint, the Ti content must be controlled under 4wt.%.

Vacuum Brazing Incoloy 800 Using the Copper Foil

2015 ◽  
Vol 1101 ◽  
pp. 99-103
Author(s):  
Cheng Yen Wang ◽  
Ren Kae Shiue
Keyword(s):  
Shear Strength ◽  
Copper Foil ◽  
Vacuum Furnace ◽  
Vacuum Brazing ◽  
Average Shear Strength ◽  
Average Shear ◽  
Incoloy 800 ◽  
Brazed Joints ◽  
Brazed Joint ◽  
Time Average

The purpose of this research is focused on vacuum furnace brazing Incoloy 800 (IN-800) using the copper filler foil. Microstructural evolution and shear strength of brazed joints for various brazing conditions has been evaluated in the experiment. The Cu-rich matrix dominates entire brazed joint. The width of Cu-rich matrix is decreased with increasing the brazing temperature and/or time. Average shear strength of the joint is approximately 215 MPa. Dimple dominated fracture is widely observed for the specimen brazed below 1160oC. However, cleavage dominated fracture is found for the specimen brazed at 1200oC. It is advised that copper brazing IN-800 alloy should be confined below 1160oC.

scholarly journals Vacuum Brazing of 55 vol.% SiCp/ZL102 Composites Using Micro-Nano Brazing Filler Metal Fabricated by Melt-Spinning

Metals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1470
Author(s):  
Dechao Qiu ◽  
Zeng Gao ◽  
Xianli Ba ◽  
Zhenjiang Wang ◽  
Jitai Niu
Keyword(s):  
Melt Spinning ◽  
Filler Metal ◽  
Aluminum Matrix ◽  
Chemical Properties ◽  
Base Material ◽  
Fracture Morphology ◽  
Aluminum Matrix Composites ◽  
Joint Shear Strength ◽  
Vacuum Brazing ◽  
Sic Particles

The joining methods of Aluminum matrix composites reinforced with SiC particles (SiCp/Al MMCs) are a challenge during the manufacturing process due to the significant differences between SiC particles and base aluminum in terms of both physical and chemical properties. Micro-nano brazing filler metal Al-17.0Cu-8.0Mg fabricated by melt-spinning technology was employed to deal with the joining problem of 55 vol.% SiCp/ZL102 composites in this work. The result indicated that the foil-like brazing filler metal contained uniformed cellular nano grains, with a size less than 200 nm. The solidus and liquidus temperatures of the foil-like brazing filler metal decreased by 4 °C and 7 °C in comparison with the values of the as-cast brazing filler metal due to the nanometer size effect. The maximum joint shear strength of 98.17 MPa achieved with a brazing temperature of 580 °C and holding time of 30 min was applied in vacuum brazing process. The width of the brazing seam became narrower and narrower with increasing brazing temperature owning to the strong interaction between the micro-nano brazing filler metal and 55 vol.% SiCp/ZL102 composites. The fracture morphology of the joint made at a brazing temperature of 580 °C was characterized by quasi-cleavage fracture. After brazing, the chemical concentration gradient between the brazing filler metal and base material disappeared.

Comparative Study on Microstructure and Strength of TiAl/Steel Joints Brazed with Ag-Cu-Ti and Ag-Cu-Zn Filler Metals

2005 ◽  
Vol 502 ◽  
pp. 467-472
Author(s):  
Hui Jie Liu ◽  
Jicai Feng
Keyword(s):  
Shear Strength ◽  
Filler Metal ◽  
Interface Structure ◽  
Medium Carbon Steel ◽  
Medium Carbon ◽  
Vacuum Brazing ◽  
Testing Method ◽  
Interface Structures ◽  
Steel Joints ◽  
Filler Metals

Vacuum brazing of a TiAl-based alloy to a medium-carbon steel has been carried out at 1173 K for 2-40 min using Ag-Cu-Ti and Ag-Cu-Zn filler metals. The formation phases and interface structure or microstructure of the joints were investigated by SEM, EPMA and XRD, and the strength of the joints was determined by the shear testing method. The experimental results indicate that (1) Ti(Cu,Al)2, Ag(s.s.), Ag-Cu eutectic and TiC phases have occurred in the TiAl/steel joints, and their amount changes with the brazing time; (2) the interface structures of the joints brazed with the Ag-Cu-Ti filler metal is TiAl/Ti(Cu,Al)2+ Ag(s.s.)/Ag(s.s.)+Ti(Cu,Al)2/TiC/steel, while the microstructure of the joints brazed with the Ag-Cu-Zn filler metal is composed of a continuous TiC layer and a mixed zone of Ti(Cu,Al)2, Ag(s.s.) and Ag-Cu eutectic; (3) the shear strength of the joints brazed with the Ag-Cu-Ti filler metal monotonously decreases with increasing brazing time, while the shear strength of the joints brazed with the Ag-Cu-Zn filler metal first rises and then decreases, accordingly an optimum brazing time exists; (4) the maximum shear strengths of the TiAl/steel joints brazed with the Ag-Cu-Ti and Ag-Cu-Zn filler metals are 170 and 190 MPa, respectively.

Vacuum Brazing of GH2132 Superalloy Using BNi-2+BNi-5 Composite Filler

2012 ◽  
Vol 602-604 ◽  
pp. 2087-2091
Author(s):  
Rui Feng Li ◽  
Zhi Shui Yu ◽  
Kai Qi
Keyword(s):  
Mechanical Properties ◽  
Intermetallic Compound ◽  
Intermetallic Compounds ◽  
Solution Phase ◽  
Solid Solution Phase ◽  
Vacuum Brazing ◽  
Vacuum Braze ◽  
Brazed Joint ◽  
Composite Filler ◽  
Boundary Penetration

In order to overcome the over formed intermetallic compound and the grain boundary penetration phenomenon in superalloys brazed joint using BNi-2 filler, the three variable portion of BNi2+BNi-5 composite filler is used to vacuum braze GH2132 superalloy. The results showed that the addition of BNi5 filler can decrease the formation of intermetallic compounds. For composite brazing filler of BNi2+40%BNi5, the brazing seam mainly composes of solid solution phase. The amounts of intermetallic compounds increased with the increase of brazing temperature and brazing clearance. The microhardness of the intermetallic compound is about 380~400 HV which is detrimental to the mechanical properties of the brazing joint.

scholarly journals Effect of Brazing Parameters on the Microstructure and Properties of SiC Ceramic Joint with Zr-Cu Filler Metal

Crystals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 93
Author(s):  
Bofang Zhou ◽  
Jinfeng Wang ◽  
Keqin Feng ◽  
Yuchen Cai ◽  
Sitan Chen
Keyword(s):  
Shear Strength ◽  
Reaction Layer ◽  
Shear Test ◽  
Filler Metal ◽  
Interface Reaction ◽  
Fracture Morphology ◽  
Holding Time ◽  
Sic Ceramic ◽  
Maximum Shear Strength ◽  
Joint Reaction

The microstructure and mechanical properties of brazing SiC ceramic with Zr-Cu filler metal under different brazing parameters (brazing temperature, holding time) were investigated. The phase of the joint reaction interface between Zr-Cu filler metal and SiC ceramic was characterized by XRD, the microstructure and fracture morphology of the brazing SiC ceramic joint were analyzed by SEM with EDS, and the strength of the joint was evaluated by compression shear test. The results show that the brazing join between SiC ceramic and Zr-Cu filler metal can be realized at the brazing temperature of 1100 °C~1300 °C, and the main products of interface reaction are ZrC and Zr2Si. The shear strength of the joint increases with the brazing temperature, and reaches the highest at 1200 °C. The thickness of interface reaction layer increases with the increase of holding time at brazing temperature of 1200 °C. Thickness of the interface reaction layer is 2.9 μm when the joint is holding for 20 min, and the maximum shear strength of the corresponding brazed SiC ceramic joint is 57 MPa.

Microstructural Change and Fracture Behavior under Different Heat Exposure Conditions on Thermal Barrier Coatings Deposited on TiAl Intermetallic Compound

2019 ◽  
Vol 810 ◽  
pp. 27-33
Author(s):  
Makoto Hasegawa ◽  
Kotatsu Hirata ◽  
Ivo Dlouhý
Keyword(s):  
Shear Strength ◽  
Intermetallic Compound ◽  
Thermal Barrier Coatings ◽  
Diffusion Layer ◽  
Heat Exposure ◽  
Microstructural Change ◽  
Thermal Barrier ◽  
Air Plasma ◽  
Barrier Coatings ◽  
Tial Intermetallic Compound

Air plasma sprayed thermal barrier coatings (APS-TBCs) deposited on the TiAl intermetallic compounds was heat exposed in air at different temperatures and times to evaluate the microstructural change and delamination behavior. The thermal barrier coating (TBC) layer, bond coat (BC) layer and substrate were composed of 4 mol% Y2O3 stabilized ZrO2, CoNiCrAlY alloy (Co-32Ni-21Cr-8Al-0.5Y (mol%)) and TiAl intermetallic compound (Ti-46Al-7Nb-0.7Cr-0.2Ni-0.1 Si (mol%)), respectively. Due to the heat exposure, diffusion of the elements occurred between the BC layer and the substrate, and diffusion layers were formed on both the BC layer and the substrate. A thermally grown oxide (TGO) layer was formed between the TBC layer and the BC layer. The thickness of the TGO layer and the diffusion layer increased with increasing exposure temperature and time. In the TBCs heat exposed at 1273 K for 200 h, a composite oxide of Al2O3 and TiO2 was formed in the BC layer. Regarding the TBCs which were as-deposited and heat exposed at 1073, 1173 K up to 200 h and at 1273 K for 10 h, delamination occurred in the TBC layer near the BC layer. In the TBCs exposed at 1273 K for 50 h or more, delamination occurred at the vicinity of the interface between diffusion layer on the substrate side and the unreacted side of the substrate too. In case that the TBCs were heat exposed at 1073 and 1173 K, the shear strength decreases after reaching the maximum value of the shear strength at 10 h heat exposure. When the TBCs were exposed to heat at 1273 K, the shear strength indicated a constant value after the shear strength increased up to 50 h. This change may be due to the change in crack path after exposure for 50 h at 1273 K.

scholarly journals Development of Low Silver AgCuZnSn Filler Metal for Cu/Steel Dissimilar Metal Joining

Metals ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 198 ◽  
Author(s):  
Peng Xue ◽  
Yang Zou ◽  
Peng He ◽  
Yinyin Pei ◽  
Huawei Sun ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Shear Strength ◽  
Penetration Depth ◽  
Aging Process ◽  
Filler Metal ◽  
Aging Treatment ◽  
304 Stainless Steel ◽  
Dissimilar Metal ◽  
Brazed Joints ◽  
Brazed Joint

The microstructure and properties of a Cu/304 stainless steel dissimilar metal joint brazed with a low silver Ag16.5CuZnSn-xGa-yCe braze filler after aging treatment were investigated. The results indicated that the addition of Ce could reduce the intergranular penetration depth of the filler metal into the stainless steel during the aging process. The minimum penetration depth in the Ag16.5CuZnSn-0.15Ce brazed joint was decreased by 48.8% compared with the Ag16.5CuZnSn brazed joint. Moreover, the shear strength of the brazed joint decreased with aging time while the shear strength of the AgCuZnSn-xGa-yCe joint was still obviously higher than the Ag16.5CuZnSn joint after a 600 h aging treatment. The fracture type of the Ag16.5CuZnSn-xGa-yCe brazed joints before aging begins ductile and turns slightly brittle during the aging process. Compared to all the results, the Ag16.5CuZnSn-2Ga-0.15Ce brazed joints show the best performance and could satisfy the requirements for cost reduction and long-term use.

scholarly journals Microstructure and Shear Strength of Brazing TiAl/Si3N4 Joints with Ag-Cu Binary Alloy as Filler Metal

Metals ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 896 ◽  
Author(s):  
Duo Dong ◽  
Dongdong Zhu ◽  
Ye Wang ◽  
Gang Wang ◽  
Peng Wu ◽  
...  
Keyword(s):  
Shear Strength ◽  
Reaction Layer ◽  
Filler Metal ◽  
Eutectic Structure ◽  
Intermetallic Alloy ◽  
Filler Alloy ◽  
Vacuum Brazing ◽  
Brazed Joints ◽  
Si3n4 Ceramics ◽  
Maximum Shear Strength

Vacuum brazing of TiAl intermetallic alloy to Si3N4 ceramics was performed using Ag-28Cu (wt.%) filler alloy. The brazing joints obtained at different brazing temperatures were studied in this work. The microstructure and the shear strength were analyzed in detail. The results show that the brazed joints could be divided into three regions: AlCu2Ti reaction layer near the Ti-48Al-2Cr-2Nb alloy, a typical Ag-Cu eutectic structure and a thin continuous TiN + Ti5Si3 reaction layer near the Si3N4 ceramics. The microstructure varied as the brazing temperature was increased from 1153 K/15 min to 1193 K/15 min. The shear strength of the joints first increased as the brazing temperature increased from 1153 K to 1173 K, and then decreased. The maximum shear strength reached 105.5 MPa at 1173 K/15 min and the mechanism was discussed.

Vacuum Brazing of Aluminum Metal Matrix Composites (70 Vol.% SiCp/Al) Using Al-15Cu-8.5Si-4Ni-1.5Mg Filler Metal

2014 ◽  
Vol 633-634 ◽  
pp. 760-763
Author(s):  
Juan Li ◽  
Ke Hong Wang
Keyword(s):  
Filler Metal ◽  
Eutectic Silicon ◽  
Primary Silicon ◽  
Holding Time ◽  
Matrix Composites ◽  
Metallurgical Bonding ◽  
Brazed Joint ◽  
Aluminum Metal Matrix Composites ◽  
Maximum Shear Strength

This work aims at brazing 70 vol.% SiCp/Al composites using Al-15Cu-8.5Si-4Ni-1.5Mg alloy powder as filler metal. The microstructures and shear strengths of the joints made with 70 vol. % SiCp/Al composites at different brazing temperature and different holding time were examined. It is found that the brazing temperature has an apparent effect on the quality of the joints. The sample brazed at 580 °C, with the holding time of 90 min demonstrates the best metallurgical bonding. The joint mainly contains α-phase, flake-like eutectic silicon, small amounts of primary silicon and bright white θ (Al2Cu) phase. The maximum shear strength of the brazed joint is 49.7MPa, and the fracture surface shows the characteristic of brittle fracture.

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