scholarly journals Effects of Interfacial Reactions on Microstructures and Mechanical Properties of 3003 Al/T2 Cu and 1035 Al/T2 Cu Brazed Joints

Crystals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 248
Author(s):  
Man Zhang
Keyword(s):  
Mechanical Properties ◽  
Shear Strength ◽  
Stress Concentration ◽  
Joint Strength ◽  
Interfacial Reactions ◽  
Composition Analysis ◽  
Dispersion Strengthening ◽  
Al Content ◽  
Brazed Joints ◽  
Filler Metals

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.

Mechanical Properties and Microstructure of SUS304 Brazed Joint with Ni-Based Filler Metals Added Cr Powder

2005 ◽  
Vol 297-300 ◽  
pp. 2767-2771
Author(s):  
Ikuo Shohji ◽  
Satoshi Takayama ◽  
Takanori Nakazawa ◽  
Ken Matsumoto ◽  
Masanori Hikita
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Joint Strength ◽  
Brazed Joints ◽  
Brazed Joint ◽  
Filler Metals

In the brazed joint of stainless steel with BNi-2 filler, brittle Cr-B compounds form in the vicinity of the centerline of the brazed joint. These compounds cause a decrease in joint strength. In this study, BNi-2 filler supplemented with Cr powder has been used in brazing stainless steel in orde r to disperse brittle Cr-B compounds uniformly in the brazed joint and improve joint strength. The mechanical properties and microstructures of the brazed joints were investigated. Moreover, a comp arison of the brazed joint with that using the BNi-2 filler was conducted.

Properties of Silver Brazing Alloys Containing Lithium / Właściwości Spoiw Srebrnych Do Lutowania Twardego Z Dodatkiem Litu

2012 ◽  
Vol 57 (4) ◽  
pp. 1087-1093 ◽  
Author(s):  
W. Gąsior ◽  
A. Winiowski
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Shear Strength ◽  
Tensile Test ◽  
Beneficial Effect ◽  
Braze Alloy ◽  
Silver Alloys ◽  
Wetting Properties ◽  
Slag Inclusions ◽  
Brazed Joints

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.

scholarly journals Analysis and Research on the Cause of Wind Turbine Blade Bolt Fracture

2021 ◽  
Vol 2133 (1) ◽  
pp. 012028
Author(s):  
Feng Yun ◽  
Jun Liu ◽  
Chunyu Liu ◽  
Xiaochun Zhao
Keyword(s):  
Mechanical Properties ◽  
Chemical Composition ◽  
Stress Concentration ◽  
Wind Turbine ◽  
Turbine Blade ◽  
Wind Farm ◽  
Composition Analysis ◽  
Chemical Composition Analysis ◽  
Mechanical Properties Testing ◽  
Load Impact

Abstract In 2019, inspection personnel of a wind farm went to the tower and found that a total of 6 bolts of blades in the hub of a wind turbine had broken and failed. In order to find out the cause of fracture, the fracture bolt was comprehensively detected and analyzed by means of appearance morphology analysis, chemical composition analysis, mechanical properties testing, microstructure testing and fracture micro-area analysis. The results show that the main reasons for the bolt fracture are as follows: under the action of the bolt’s constantly changing and repeated wind load impact and the alternating load caused by blade rotation during the operation of the fan, the crack source is formed along the bottom of the thread with serious stress concentration and expands in fatigue mode until the whole fracture fails.

Effect of Tin Content on the Microstructure and Property of Brazed WC-Co/CrMo Alloy Steel Joints

2008 ◽  
Vol 47-50 ◽  
pp. 596-599
Author(s):  
Hsin Fu Wang ◽  
Liu Ho Chiu ◽  
Heng Chang
Keyword(s):  
Shear Strength ◽  
Braze Alloy ◽  
Alloy Layer ◽  
Vacuum Brazing ◽  
Cu Alloy ◽  
Brazed Joints ◽  
Tin Content ◽  
Steel Joints ◽  
Filler Metals ◽  
Maximum Shear Strength

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.

Effects of Ni and Co Additions to Filler Metals on Ag-Brazed Joints of Cemented Carbide and Martensitic Stainless Steel

2014 ◽  
Vol 922 ◽  
pp. 322-327 ◽  
Author(s):  
Kengo Kaiwa ◽  
Shinji Yaoita ◽  
Tomohiro Sasaki ◽  
Takehiko Watanabe
Keyword(s):  
Stainless Steel ◽  
Joint Strength ◽  
Martensitic Stainless Steel ◽  
Braze Alloy ◽  
Cemented Carbide ◽  
Suppression Effect ◽  
Brazed Joints ◽  
Co Addition ◽  
Multiple Addition ◽  
Filler Metals

This study focuses on understanding the effect of Ni and Co additions to filler metals on Ag-brazed joints of cemented carbide and martensitic stainless steel. Ni and Co added braze alloys were processed based on Ag-Cu-Zn ternary alloy, and joint strength and microstructure of the brazed layer has been investigated. The joint strength increased by the 2.0mass%Ni and 0.5mass%Co addition into braze alloy. This trend is remarkable in the Co added alloy, and the brazed joint increased by 141% compared to that in no-added alloy. The joint strength was closely related to the suppression effect of Co dissolution from cemented carbide into filler layer and Fe diffusion from the stainless steel to the brazed layer. In the brazed microstructure, Co-depleted zone caused by dissolution of Co in the cemented carbide was observed near the interface between the cemented carbide and the steel. Width of the Co-depleted zone significantly decreased in the Co added alloy. However, the joint strength decreased in the multiple addition compared to that in the single addition of Ni or Co.

scholarly journals Reactive Air Brazing of TiAl Alloy Using Ag-CuO: Microstructure and Joint Properties

Crystals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1496
Author(s):  
Haoran Yang ◽  
Xiaoqing Si ◽  
Chun Li ◽  
Jian Cao
Keyword(s):  
Mechanical Properties ◽  
Shear Strength ◽  
Tial Alloy ◽  
Oxide Layers ◽  
Wetting Behavior ◽  
Air Atmosphere ◽  
Microstructure And Mechanical Properties ◽  
Joint Properties ◽  
Brazed Joints ◽  
Maximum Shear Strength

TiAl alloy was successfully brazed with Ag-CuO filler in air atmosphere under simple technical conditions. The wettability of a series of Ag-CuO fillers on TiAl was analyzed. Ag-2mol%CuO filler possessed good wetting behavior on TiAl alloy. The microstructure and mechanical properties of the brazed joints were investigated. Oxide layers can be found on both sides, which can be divided into external TiO2-rich layer and internal Al2O3-rich layer. The maximum shear strength of the joint was obtained at 1020 °C holding for 20 min.

scholarly journals Influence of Holding Time on Properties of Cemented Carbide-polycrystalline Diamond Compact Joints

2015 ◽  
Vol 9 (1) ◽  
pp. 33-38
Author(s):  
Jia Qianzhong ◽  
Li Man ◽  
Qu Fuzheng ◽  
Zhang Hongtao
Keyword(s):  
Solid Solution ◽  
Shear Strength ◽  
Polycrystalline Diamond ◽  
Holding Time ◽  
Cemented Carbide ◽  
Joint Interface ◽  
Strengthening Effect ◽  
Dispersion Strengthening ◽  
Electron Probe Microanalyzer ◽  
Brazed Joints

The influence of brazing holding time on properties of cemented carbide-polycrystalline diamond (PCD) compact joints were investigated in this study. The microstructure and phase composition of joints were investigated by scanning electron microscopy, electron probe microanalyzer, and X-ray diffraction. Microstructural investigations revealed the presence of Ag-based solid solution, Cu-based solid solution, Cu0.64Zn0.36, and a small amount of MnNi phase at the joint interface. The max shear strength of brazed joints 350.6 MPa was determined in the samples joined at 15 s, which was partially due to the dispersion strengthening effect of gray-black grains containing Cu-based solid solution, Cu0.64Zn0.36 and MnNi phase in the joints. Equal-area-circle grain diameter of the gray-black grains grew with longer holding time, whereas the shear strength decreased because of the formation of continuous intermetallic compounds layer along the joint boundary. Thermal damage of the PCD layer also deteriorated with increased holding time, and hence shorter holding time was preferable in the production.

Fracture Mechanism of Aluminum Joint Brazed by Zn-Al Alloy

2012 ◽  
Vol 538-541 ◽  
pp. 1697-1700
Author(s):  
Man Zhang ◽  
Hai Lin Jiang ◽  
Hong Bin Xu ◽  
Yue Bin Lin
Keyword(s):  
Stress Concentration ◽  
Fracture Mechanism ◽  
Joint Strength ◽  
Filler Metal ◽  
Al Alloy ◽  
Pure Aluminium ◽  
Al Content ◽  
Surrounding Structure ◽  
Joint Fracture ◽  
Brazed Joint

Zn-Al alloy microstructures were investigated, moreover, the strength and microstructures of pure aluminium brazed joint had been studied. Joint fracture mechanism was analyzed. The results indicate that the blocky microstructure in the cast 85Zn-15Al filler metal is granular and fine. Accordingly, the blocky eutectoid structure in the joint brazed by 85Zn-15Al is fine and even. Stress concentration emerges difficultly between fine blocky eutectoid structure and its surrounding structure. So the joint strength is highest. When Al content in the Zn-Al alloy exceeds 15wt.%, the blocky eutectoid structure become large in the cast filler metal and the brazed joint. The brazed joint strength decreases.

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