scholarly journals Effect of Various Nanoparticles (GaF3, ZnF2, Zn(BF4)2 and Ga2O3) Additions on the Activity of CsF-RbF-AlF3 Flux and Mechanical Behavior of Al/Steel Brazed Joints

Crystals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 683 ◽  
Author(s):  
Zhen Yao ◽  
Songbai Xue ◽  
Junxiong Zhang

In this study, brazing AA6061 to Q235 steel using flame brazing was performed with 70.9 wt.% CsF-0.5 wt.% RbF-28.6 wt.% AlF3 fluxes doped with GaF3, ZnF2, Zn(BF4)2 and Ga2O3 nanoparticles, matched with a Zn-15Al filler metal, and the spreadability of the filler metal and the mechanical properties of brazed joints were investigated at the same time. The results showed suitable amounts of GaF3, ZnF2, Zn(BF4)2 and Ga2O3 doped into the base flux could strengthen the filler metal in wetting and spreading on the surface of aluminum alloy and steel to different degrees. The suitable ranges of GaF3, ZnF2, Zn(BF4)2 and Ga2O3, respectively, were 0.0075–0.01 wt.%, 0.0075–0.01 wt.%, 0.0075–0.01 wt.% and 0.009–0.01 wt.%, and the maximum spreading area was obtained via doping with GaF3. The shear strength of brazed joints reached the peak at 126 MPa when 0.075 wt.% GaF3 was added. Comparative tests proved that the activity of the CsF-RbF-AlF3 flux doped with GaF3 was the best. The reason was that the CsF-RbF-AlF3-GaF3 flux was competent in removing oxides of the base metal and decreasing the interfacial tension, in virtue of the activity of Ga3+ as well as F−.

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.


Alloy Digest ◽  
1999 ◽  
Vol 48 (12) ◽  

Abstract Kaiser Aluminum Alloy 7049 has high mechanical properties and good machinability. The alloy offers a resistance to stress-corrosion cracking and is typically used in aircraft structural parts. This datasheet provides information on composition, physical properties, hardness, tensile properties, and shear strength as well as fatigue. It also includes information on forming, heat treating, machining, and surface treatment. Filing Code: AL-365. Producer or source: Tennalum, A Division of Kaiser Aluminum.


Alloy Digest ◽  
1999 ◽  
Vol 48 (10) ◽  

Abstract Kaiser Aluminum alloy KA62 (Tennalum alloy KA62) is a lead-free alternative to 6262. It offers good machinability and corrosion resistance and displays good acceptance of coatings (anodize response). It can be used in place of 6262 because its physical and mechanical properties are equivalent to those of 6262 (see Alloy Digest Al-361, September 1999). This datasheet provides information on composition, physical properties, hardness, tensile properties, and shear strength. It also includes information on corrosion resistance as well as forming, heat treating, machining, and surface treatment. Filing Code: AL-362. Producer or source: Tennalum, A Division of Kaiser Aluminum.


Alloy Digest ◽  
1988 ◽  
Vol 37 (11) ◽  

Abstract UNS A96061 is a wrought precipitation-hardenable aluminum alloy having excellent resistance to corrosion and good mechanical properties. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and shear strength as well as fatigue. It also includes information on low and high temperature performance, and corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Al-292. Producer or source: Various aluminum companies.


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 (4) ◽  
pp. 248
Author(s):  
Man Zhang

To meet the demand for efficient and reliable copper and aluminum (Cu/Al) joints in refrigeration and electric power industries, interfacial reactions in 3003 Al/T2 Cu and 1035 Al/T2 Cu joints brazed by Zn-xAl (x ranged from 2–25 wt.%) filler metals and their effects on the mechanical properties of the joints were investigated. Microstructures and fracture surfaces were observed combining with composition analysis. For 3003 Al/Cu joints, bulk CuAl and CuAl2 intermetallic compound (IMC) formed in brazing seams, and a CuAl IMC layer formed at the Cu side interfaces. For 1035 Al/Cu joints, bulk CuAl2 IMC formed in brazing seams, and an Al4.2Cu3.2Zn0.7 IMC layer formed at the Cu side interfaces. For both kinds of joints, shear strength increased first, then decreased with the increasing Al content. The increase in shear strength was because Al promoted the formation of Cu-Al IMC, and caused dispersion strengthening. With the excessive Al content, however, the bulk IMC became coarse and the IMC layers at Cu side interfaces grew thick, causing the joint strength to decrease due to stress concentration. The strength of 3003 Al/Cu joints was always higher than that of 1035 Al/Cu, and their highest strength were achieved by Zn-12Al and Zn-15Al, respectively.


2020 ◽  
Vol 34 (08) ◽  
pp. 2050064 ◽  
Author(s):  
Meng Zhao ◽  
Liang Zhang ◽  
Lei Sun ◽  
Ming-yue Xiong ◽  
Nan Jiang ◽  
...  

In this study, the effects of Cu nanoparticles on the melting characteristics, wettability, interfacial reaction and mechanical properties of [Formula: see text]–[Formula: see text] [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text] composite solders were investigated. Results show that the properties of the composite solder containing Cu nanoparticles were improved effectively. With the addition of Cu nanoparticles, the melting point of [Formula: see text]–[Formula: see text] solder decreased significantly, and the spreading area and the shear strength were increased by 10.3% and 23.2%, respectively. For the performance, the optimal addition of Cu nanoparticles was 0.7%. In addition, the growth of interfacial intermetallic compounds in [Formula: see text]–[Formula: see text] solder joints was inhibited by adding Cu nanoparticles.


2012 ◽  
Vol 57 (4) ◽  
pp. 1087-1093 ◽  
Author(s):  
W. Gąsior ◽  
A. Winiowski

The analysis of the influence of lithium on wetting properties of Ag-Cu brazing alloys and the shear strength of stainless steel/braze/stainless steel joint was conducted. The brazing alloys of designations and composition according to ANSI/AWS A5.8: BAg-8a (71÷3 wt.% Ag, 0.25÷0.50 wt.% Li, Cu) and BAg-19 (92÷93 wt.% Ag, 0.15÷0.30 wt.% Li, Cu) and a braze alloy containing 70÷72 wt.% Ag, 0.6÷0.7 wt.% Li and Cu were subjected to the investigations. The wettability properties of the brazing silver alloys were examined in a spread test. The shear strength of joints were measured on the joints of stainless steel in the tensile test. The comparison of results showed a beneficial effect of lithium on the spreading properties and the wettability of braze alloys as well as the quality and shear strength of the brazed joints. The observed slag inclusions in the solid braze did not affect considerably the mechanical properties of the prepared joints because of the intensive deoxidation of the brazing surfaces of stainless steel elements.


2017 ◽  
Vol 31 (16-19) ◽  
pp. 1744040
Author(s):  
Dengquan Han ◽  
Yuanxing Li ◽  
Yongpan He ◽  
Sifu Qiu ◽  
Hui Chen

Aluminum alloy 5083 was joined with Sn–[Formula: see text]Zn ([Formula: see text], 5, 9, 30 and 60 wt.%) filler metal by ultrasonic soldering at 400[Formula: see text]C. The joint microstructure consisted of [Formula: see text]-Sn and [Formula: see text]-Al solid–solution phases when using pure Sn solder. Zn-rich phases were observed in the joints with Sn–Zn filler metal. The Zn-rich phases grew thicker and larger with the increase in Zn content in the filler metal. The joints soldered with Sn–30Zn filler metal reached a maximum shear strength of 70 MPa. Joint cracking occurred at the interface of pure Sn and Sn–9Zn solders as indicated by SEM observation of the fracture surfaces. The locations of the fracture surface moved from the interface to the seam when using the Sn–30Zn or Sn–60Zn filler metal. The coarse Zn-rich phases were also observed on the fracture surface using Sn–60Sn solder, which results in a shear strength reduction of the joints.


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