Brazing of Aluminum Bimetallic Sheets in the Design of Heat Exchangers

2013 ◽  
Vol 814 ◽  
pp. 19-24
Author(s):  
Ionel Olaru
Keyword(s):  
Heat Transfer ◽  
Melting Point ◽  
Heat Exchangers ◽  
Filler Metal ◽  
Base Material ◽  
Base Materials ◽  
High Durability ◽  
Brazed Joint ◽  
Good Heat ◽  
Efficient Realization

Present heat exchangers should ensure very good heat transfer while having as small size, high durability and the optimum performance at low prices. Thus to achieve these goals is used as base material, aluminum in various forms, of which can be made the heat exchangers energetic efficient. Realization of aluminum heat exchangers can be properly with present requirements using the brazing joint elements. Brazing achieved joining with temperature for two base materials using a filler metal with a melting point above 450°C. A properly brazed joint is performed with a metallurgical connection between two or more metals, which is generally as strong as or stronger than the base metal used.

Resistance Welding by Inserting Wires between Joint Interfaces

2007 ◽  
Vol 127 ◽  
pp. 343-347
Author(s):  
Takeshi Terajima ◽  
Toshio Kuroda
Keyword(s):  
Stainless Steel ◽  
Melting Point ◽  
Base Material ◽  
Resistance Welding ◽  
Joint Interface ◽  
Base Materials ◽  
Steel Wires ◽  
Material Temperature ◽  
Type 316L Stainless Steel

Butt resistance welding of super duplex stainless steel by inserting type 316L stainless steel wires was investigated. When the base material temperature was increased from room temperature to 1100 oC at the heating rate of 550 oC /sec, base materials were jointed through the insert wires and HAZ (heat affected zone) of the joint interface were less than 80 μm. In this joining technique, the insert wires played a role of concentrating current on the wires and increasing their temperature up to melting point or near melting point. When the welding was performed at a load of 10 N, the insert wires consisted of ferrite and austenite growing along the ferrite grain boundary. When the welding was performed at a load of 70N, insert wire remained austenite. That is because the contact resistance between insert wire and base materials at 70 N was lower than that of 10 N, and consequently the insert wire were not adequately heated.

Advanced aluminum alloys for aircraft brazed structures

2021 ◽  
pp. 179-192
Author(s):  
E.N. Kablov ◽  
N.V. Dynin ◽  
I. Benarieb ◽  
N.D. Shchetinina ◽  
S.V. Samokhvalov ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Corrosion Resistance ◽  
High Temperature ◽  
Aluminum Alloys ◽  
Heat Exchangers ◽  
Base Material ◽  
Additive Technologies ◽  
Technical Literature ◽  
Vacuum Brazing

Review of domestic and foreign scientific and technical literature in the fi eld of application of aluminum alloys for brazed structures of aircraft heat exchangers manufactured by high-temperature vacuum brazing is provided. Prospective developments of domestic aluminum alloys for application as base material for clad sheets for brazed structures of heat exchangers are presented. The possibilities for increasing of the corrosion resistance of heat transfer surfaces are considered. The possibilities for application of additive technologies for the manufacture of aluminum heat exchangers alloys are considered.

scholarly journals Research on a Low Melting Point Al-Si-Cu (Ni) Filler Metal for 6063 Aluminum Alloy Brazing

2021 ◽  
Vol 11 (9) ◽  
pp. 4296
Author(s):  
Chengyin Peng ◽  
Dandan Zhu ◽  
Kaifeng Li ◽  
Xiang Du ◽  
Fei Zhao ◽  
...  
Keyword(s):  
Shear Strength ◽  
Aluminum Alloy ◽  
Melting Point ◽  
Filler Metal ◽  
Shear Strength Test ◽  
Primary Si ◽  
Al2cu Phase ◽  
Brazed Joint ◽  
New Type ◽  
6063 Aluminum Alloy

A new type of low melting point Al-Si-Cu (Ni) filler metal for brazed 6063 aluminum alloy was designed, and the microstructure and properties of the filler metal were systematically studied. The results show that when the content of Cu in the Al-Si-Cu filler metal increased from 10 wt.% to 20 wt.%, the liquidus temperature of the filler metal decreased from 587.8 °C to 533.4 °C. Its microstructures were mainly composed of the α-Al phase, a primary Si phase, and a θ(Al2Cu) phase. After a proper amount of Ni was added to the Al-Si-20Cu filler metal, its melting range was narrowed, the spreading wettability was improved, and the microstructure was refined. Its microstructure mainly includes α-Al solid solution, Si particles, and θ(Al2Cu) and δ(Al3Ni2) intermetallic compounds. The results of the shear strength test indicate that the shear strength of the brazed joint with Al-6.5Si-20Cu-2.0Ni filler metal was 150.4 MPa, which was 28.32% higher than that of the brazed joint with Al-6.5Si-20Cu filler metal.

Precise Resistance Welding with Wire Insert

2007 ◽  
Vol 539-543 ◽  
pp. 3900-3905
Author(s):  
Takeshi Terajima ◽  
Toshio Kuroda
Keyword(s):  
Stainless Steel ◽  
Melting Point ◽  
Base Material ◽  
Resistance Welding ◽  
Joint Interface ◽  
Base Materials ◽  
Steel Wires ◽  
Material Temperature ◽  
Wire Insert

Butt resistance welding of super duplex stainless steel type 329J4L with inserting type 316L stainless steel wires was investigated. When the base material temperature was increased from room temperature to 1373 K at the heating rate of 550 K /sec, base materials were jointed through the insert wires. HAZ (heat affected zone) of the joint interface were less than 80 μm. In this jointing technique, the insert wires played an important role of concentrating current on the wires and increasing their temperature up to melting point or near melting point. Thermal analysis using thermography revealed that insert wires were adequately heated just after current started at a load of 10 N. When the welding was performed at a load of 70 N, joint area was increased by plastic deformation of the base material. That led to decrease of current concentration. Consequently insert wires were jointed in the solid state.

Brazing of Cemented Carbides at Lower Temperatures

2011 ◽  
Vol 409 ◽  
pp. 865-870
Author(s):  
Shinji Yaoita ◽  
Takehiko Watanabe ◽  
Tomohiro Sasaki
Keyword(s):  
Mechanical Properties ◽  
Melting Point ◽  
Abrasion Resistance ◽  
Bending Strength ◽  
Filler Metal ◽  
Cutting Tools ◽  
High Hardness ◽  
Cemented Carbides ◽  
Brazed Joint ◽  
Tool Shank

Cemented carbides have been widely used for cutting tools because of their high hardness and abrasion resistance. Since the cemented carbides are so expensive, it is desirable to reuse a tool shank made of cemented carbides. For the reason, so far, a new blade of a tool has been brazed to used shanks. However, when cemented carbides are heated for brazing, heating inevitably causes the deterioration in the mechanical properties. This study was carried out to braze the cemented carbides at lower temperatures for reducing the deterioration of the shank. First of all, authors developed a new Ag-based brazing filler metal with a low melting point of about 605°C, and investigated the effects of the new Ag filler metal on the properties of a brazed joint. Moreover, Co element or Ni element was added into the Ag filler metal to make the bending strength of a brazed joint improved. The addition of Co element increased the bending strength of a joint and the strength was equivalent to that of a joint brazed at 750°C using a conventional Ag filler metal, but the addition of Ni element decreased the bending strength of a brazed joint.

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