Vacuum brazing of TiAl alloy to 40Cr steel with Ti60Ni22Cu10Zr8 alloy foil as filler metal

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.

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Experimental Investigation of Copper/Stainless Steel Joints Formed by Vacuum Brazing

18th International Conference on Nuclear Engineering: Volume 5 ◽

10.1115/icone18-29132 ◽

2010 ◽

Author(s):

Changqing Ye

Keyword(s):

Stainless Steel ◽

Copper Alloy ◽

Filler Metal ◽

Dissimilar Materials ◽

Optical Microscope ◽

Interface Zone ◽

Vacuum Brazing ◽

Bonded Joint ◽

Steel Composite ◽

Steel Joints

The article presents a study of two different brazing joints produced by dissimilar materials vacuum brazing. The junctions were obtained between copper or copper alloy and stainless steel. Different brazing parameters were used according to the different type of samples. By using optical microscope, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and micro-hardness machine to analyze the microstructure of copper or copper alloy/stainless steel vacuum brazing joins. The test results showed that copper (T2)/stainless steel (1Cr18Ni9Ti) dissimilar materials were successfully bonded together by means of the advanced vacuum brazing technology (the grade of filler metal was B-Ag72Cu). The interface zone of copper (T2)/stainless steel (1Cr18Ni9Ti) brazing bonded joint included the copper side interface, the middle brazing transition zone and stainless steel side. Some defects such as microfissures were also found in the brazing seam between copper alloy and stainless steel composite components obtained by vacuum brazing using B-AgCu21Pd25 filler metal. They are mainly due to the process and geometry parameters, such as temperature and clearance.

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Impact of Tin and Nickel on the Brazing Properties of Silver Filler Metals and on the Strength of Brazed Joints Made of Stainless Steels

Archives of Metallurgy and Materials ◽

10.2478/amm-2013-0118 ◽

2013 ◽

Vol 58 (4) ◽

pp. 1007-1011 ◽

Cited By ~ 9

Author(s):

A. Winiowski ◽

M. Rózanski

Keyword(s):

Stainless Steels ◽

Shear Test ◽

Filler Metal ◽

Positive Impact ◽

Energy Dispersive Spectrometer ◽

Light And Electron Microscopy ◽

Vacuum Brazing ◽

Brazed Joints ◽

Structural Tests ◽

Filler Metals

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.

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Vacuum brazing of super-Ni/NiCr laminated composite to Cr18–Ni8 steel with NiCrP filler metal

Journal of Materials Processing Technology ◽

10.1016/j.jmatprotec.2011.11.003 ◽

2012 ◽

Vol 212 (4) ◽

pp. 794-800 ◽

Cited By ~ 12

Author(s):

Na Wu ◽

Yajiang Li ◽

Juan Wang ◽

U.A. Puchkov

Keyword(s):

Filler Metal ◽

Laminated Composite ◽

Vacuum Brazing

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

Materials Science Forum ◽

10.4028/www.scientific.net/msf.502.467 ◽

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.

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