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

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.

Metals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 526
Author(s):  
Yuzhen Lei ◽  
Hong Bian ◽  
Wei Fu ◽  
Xiaoguo Song ◽  
Jicai Feng ◽  
...  

Titanium and zirconia (ZrO2) ceramics are widely used in biomedical fields. This study aims to achieve reliable brazed joints of titanium/ZrO2 using biocompatible Au filler for implantable medical products. The effects of brazing temperature and holding time on the interfacial microstructures and mechanical properties of titanium/Au/ZrO2 joints were fully investigated by scanning electron microscopy (SEM), energy-dispersive spectrometry (EDS) and X-ray diffraction (XRD). The results indicated that the typical interfacial microstructure of the titanium/Au/ZrO2 joint was titanium/Ti3Au layer/TiAu layer/TiAu2 layer/TiAu4 layer/TiO layer/ZrO2 ceramic. With an increasing brazing temperature or holding time, the thickness of the Ti3Au + TiAu + TiAu2 layer increased gradually. The growth of the TiO layer was observed, which promoted metallurgical bonding between the filler metal and ZrO2 ceramic. The optimal shear strength of ~35.0 MPa was obtained at 1150 °C for 10 min. SEM characterization revealed that cracks initiated and propagated along the interface of TiAu2 and TiAu4 reaction layers.


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.


Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1844
Author(s):  
Shengnan Li ◽  
Dong Du ◽  
Lei Zhang ◽  
Qingle Hao ◽  
Weimin Long

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.


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.


2020 ◽  
Vol 40 (3) ◽  
pp. 90-95
Author(s):  
Zeng Gao ◽  
Jianguang Feng ◽  
Xingkong Tao ◽  
Fengsong Ma ◽  
Jitai Niu

In this paper, the effect of different surface pretreatment method on properties of vacuum brazed joint of AlSi50 alloy was investigated. The surface pretreatment methods of specimen before brazing include sanding, NaOH corrosion, HCl corrosion, H2SO4 corrosion and nickel plating. The experimental results indicate that the width of brazing joint varies with different surface pretreatment methods. The joint with sanding pretreatment, has the largest brazing seam width of 20 μm. Meanwhile, joint with H2SO4 corrosion has the narrowest brazing seam width. The brazing filler metal can wet and spread on different pretreated specimen very well. Spectrum analysis indicates that nickel-plate on AlSi50 surface, can interact with brazing filler metal, which increases mechanical property of brazing joint. For brazing of AlSi50 alloy, the optimal pretreatment method is nickel plating. After nickel plating pretreatment, brazing joint has the maximum shear strength 82.05 MPa by using brazing filler metal Al52-Cu33-Mg12-Ni3 and following technological parameters: brazing temperature 580 ℃, soaking time 30 min and pressure 3 MPa.


2013 ◽  
Vol 788 ◽  
pp. 34-37
Author(s):  
Fei Lin ◽  
Jie Li ◽  
Hong Wei Zhao ◽  
Zhi Tong Chen ◽  
Qing Sen Meng

Vacuum diffusion bonding of as-extruded AZ61 magnesium alloy was investigated according to atomic diffusion theory. The effects of the diffusion temperature and holding time on the quality of the bonding joint are investigated by means of microstructure analysis, shearing strength test and microhardness testing. The shearing test results showed that the maximum shearing strength reached 51.95MPa with the temperature of 470°C and the holding time of 90min. And the diffusion temperature and holding time have a great effect on the quality of the bonding joints. The microhardness measurement results showed that the microhardness value at the bonding joint was maximum.


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