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 ◽  
...  

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.

Crystals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 93
Author(s):  
Bofang Zhou ◽  
Jinfeng Wang ◽  
Keqin Feng ◽  
Yuchen Cai ◽  
Sitan Chen

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.


2008 ◽  
Vol 47-50 ◽  
pp. 596-599
Author(s):  
Hsin Fu Wang ◽  
Liu Ho Chiu ◽  
Heng Chang

Vacuum brazing of Cemented Tungsten Carbide (WC-Co) and JIS SCM440 steel using Cu-Sn braze alloy has been studied. The effect of Sn content in the filler metals on the properties of brazed joints was investigated. The specimens were brazed under 1050°C to 1110°C for 5 to 15 minutes. The experimental results show that the maximum shear strength is 341±15MPa for the joints brazed at 1080°C for 10 min by using Cu-9Sn filler. Shear strength of the joints brazed at 1050°C and 1080°C increased as Sn content added to the braze alloy. However, joints brazed at 1110°C showed a decline in shear strength as the increase of Sn content. From SEM micrographs, a Fe-Co-Cu alloy layer was formed at WC-Co/Cu-Sn interface and the property of the layer was affected by brazing temperature and Sn content.


2005 ◽  
Vol 297-300 ◽  
pp. 2441-2446 ◽  
Author(s):  
Shi Yao Qu ◽  
Zeng Da Zou ◽  
Xin Hong Wang

Shear strength and fracture behavior of Al2O3 matrix ceramic composite brazed joints to carbon steel with Ag-Cu-Ti brazing alloy in flow argon have been studied by means of SEM, EDX and all-purpose testing machine. Results have shown that there is a close relationship between the shear strength and the fracture form of brazed joints. The fracture occurring completely in the composite near the composite/filler metal interface corresponds to the low strength of a joint, and the strength of the joint fractured partially in the composite usually increases with decreasing the proportion of the composite on the fracture surface in the steel side. When the fracture occurs in the reaction layer between the composite and the filler metal, the closer the fractured position comes to the composite/reaction layer interface, the higher the joint strength. The maximum shear strength is obtained when the fracture occurs fully at the interface.


2009 ◽  
Vol 416 ◽  
pp. 264-268 ◽  
Author(s):  
Yan Chen ◽  
Hong Jun Xu ◽  
Yu Can Fu ◽  
Hong Hua Su

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.%.


2019 ◽  
Vol 91 (10) ◽  
pp. 35-41 ◽  
Author(s):  
Li Hong ◽  
Liu Xuan ◽  
Huang Haixin

Reliable ceramics/metal joints have an extensive application in the aerospace and biomedical area. However, ZrO2ceramic has not been investigated systematically compared to the Si3N4and Al2O3ceramic. Therefore, successful brazing of ZrO2ceramic and Ti-6A-4V alloy was achieved by using a binary active Ti-28Ni filler metal in this paper. The effect of holding time on the microstructure of ZrO2 ceramic/filler metal interface and mechanical properties of brazed joints was investigated. The results indicated that the representative interfacial microstructure was ZrO2ceramic/Ti2O/Ni2Ti4O/Ti-rich phase/Ti2Ni+α-Ti. With the increase of holding time, the thickness of Ti-rich layer in the interface of ZrO2/Ti-6Al-4Vjoint decreased obviously due to the diffusion of Ti atoms. Substantial brittle intermetallic compounds Ti2Ni and Ni2Ti4O were formed in the joint, which were detrimental to the mechanical properties of the brazed joints. The maximum shear strength of joint was 112.7 MPa when brazed at 1060 °C for 10 min.


2013 ◽  
Vol 544 ◽  
pp. 167-171 ◽  
Author(s):  
Jia Ke Li ◽  
Xiu Liu ◽  
Jian Er Zhou

C/SiC composite and TC4 alloy were successfully brazed using 70Ag28Cu2Ti (wt. %) as filler metal at 820 °C~920 °C for 5 min ~30 min. The effects of brazing parameters on the microstructures, phase composition, shear strength of the brazed joints were investigated by SEM, XRD. The mechanical performances of the brazed joints were measured by a universal mechanical testing machine. The results show that successful joining of C/SiC composite and TC4 alloy owes to interfacial reactions between the brazing alloy and the parent materials, and resultantly produce TiC, Ti5Si3 and Ti-Cu serial compounds at the interfaces; the interfacial structure of the brazed joint is C/SiC composite / TiC / Ti5Si3 /Ag (s.s) +Cu (s.s) / TiCu2 / Ti3Cu4 / TiCu / Ti2Cu / TC4 from C/SiC composite side to TC4 alloy side; the maximum shear strength of the brazed joint is 53.3 MPa at 860°C for 10min.


2015 ◽  
Vol 1101 ◽  
pp. 99-103
Author(s):  
Cheng Yen Wang ◽  
Ren Kae Shiue

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.


Entropy ◽  
2019 ◽  
Vol 21 (3) ◽  
pp. 283 ◽  
Author(s):  
Chieh Lin ◽  
Ren-Kae Shiue ◽  
Shyi-Kaan Wu ◽  
Huai-Li Huang

Infrared vacuum brazing of CoCrFeMnNi high entropy alloy (HEA) using BNi-2 and MBF601 fillers has been investigated. Both brazes show poor wettability at temperatures only 20 °C above their liquidus temperatures. However, the wettability of BNi-2 and MBF601 fillers on CoCrFeMnNi HEA is greatly improved with increasing the test temperatures, 50 °C above their liquidus temperatures. The BNi-2 brazed joints are dominated by Ni-rich matrix with huge CrB and a few tiny boride precipitates. Average shear strengths of joints increase with increasing brazing temperature and/or time, and fracture location changes from blocky CrB in the brazed zone to grain boundary boride in the substrate. The MBF601 brazed joints are composed of CoCrFeMnNi-based matrix, particles of B/Co/Cr/Fe/Mn/Ni/P compounds, and some phosphides form along the grain boundaries of the substrate. The specimen brazed with MBF601 filler foil at 1050 °C for 600 s has the highest average shear strength of 321 MPa, while that brazed at 1080 °C for 600 s has a lower average shear strength of 271 MPa due to the presence of solidification shrinkage voids.


2013 ◽  
Vol 58 (4) ◽  
pp. 1007-1011 ◽  
Author(s):  
A. Winiowski ◽  
M. Rózanski

Abstract The research involved vacuum tests of brazing properties of silver filler metals, containing tin as well as tin and nickel, and used in brazing of chromium X6Cr17 and chromium-nickel X6CrNiTi18-10 stainless steels. The research also involved testing the strength and structural properties of brazed joints made of these steels. The tests were conducted on filler metals (silver brazing alloys) B-Ag68CuSn-730/755 (Ag68Cu28Sn4) and B-Ag65CuSnNi-740/767 (Ag65Cu28Sn5Ni2) and also, for comparative purposes, on the filler metal B-Ag72Cu-780 (Ag 272 according to PN-EN ISO 17672), most commonly applied in the vacuum brazing of high alloyed stainless steels. The brazing properties of the filler metals were tested by determining their wettability by means of the spreadability method. The strength of brazed joints made of the stainless steels was examined in a shear test. Research-related structural tests involved light and electron microscopy with an energy dispersive spectrometer (EDS). The comparative analysis of the properties of the filler metals revealed the positive impact of tin and nickel on the spreadability and wettability of the silver brazing alloys as well as on the quality and the shear strength of brazed joints.


2008 ◽  
Vol 47-50 ◽  
pp. 682-685 ◽  
Author(s):  
Liu Ho Chiu ◽  
Hsin Fu Wang ◽  
Chia Pao Huang ◽  
Ching Tsung Hsu ◽  
Tsung Chi Chen

The effect of brazing temperature on the properties of brazed joints between WC-Co hard alloy and SAE1045 carbon steel using Cu and ASTM C52100 bronze metal as insert fillers were investigated. A vacuum brazing furnace was employed to conduct the experiment with different sets of operational parameters (brazing temperature, bonding time and filler) were used. The experimental result shows that Fe-Co-Cu alloy layer was formed at the WC-Co/Cu filler interface. With increased brazing temperature and bonding time, the thickness of the Fe-Co-Cu layer increases. From the shear test, the maximum shear strength is 320±10 MPa for the joint brazed at 1140°C for 15 min using Cu filler. The shear strength of WC-Co/C52100/SAE1045 brazed joints was better than WC-Co/Cu/SAE1045 brazed joints. The increase of bonding time of WC-Co/C52100/SAE1045 joints improved the shear strength slightly.


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