Analysis of Organizations of Brazed Seam 5052 Al Alloy Contact Reactive Brazing

2013 ◽  
Vol 690-693 ◽  
pp. 2598-2600 ◽  
Author(s):  
Fen Fang Tan ◽  
Kang Du

Test of 5052 Al alloy contact reactive brazing has been conducted in the case of special brazing parameters, using Cu foil-Mg power-Cu foil as reaction layer material, the microstructure were analyzed and discussed primarily. The results show that the brazing seam structure consisted of α-Al solid solution and CuAl2 intermetallic compound; the organizations of brazed seam include Al (Mg, Cu) solid solution CuAl2 binary intermetallic compound, complicated ternary intermetallic compound and Al2MgO4.

Author(s):  
D. Faulkner ◽  
D. J. Cameron

Zr-Al alloys based on the intermetallic compound Zr3Al are presently being considered as structural materials for use in nuclear environments. Theoretically, the single-phase Zr3Al alloy should contain 8.97% Al, but in practice single phase material is not produced, and alloys containing approximately 8.0 to 8.5% Al contain a dispersion of α-Zr solid solution in the Zr3Al matrix (fig. 1). At higher Al concentrations Zr2Al may also be present.In this paper we describe the structures observed in a Zr-8.3% Al alloy containing up to 1300 μg/g hydrogen. Hydrogen was introduced into the alloy in two ways. The first technique involved the exposure of a weighed sample, at 650°C to a known volume of hydrogen at a predetermined pressure. The pressure was monitored during hydriding until it dropped to a value corresponding to the required uptake of hydrogen.


Author(s):  
C. S. Lin ◽  
W. A. Chiou ◽  
M. Meshii

The galvannealed steel sheets have received ever increased attention because of their excellent post-painting corrosion resistance and good weldability. However, its powdering and flaking tendency during press forming processes strongly impairs its performance. In order to optimize the properties of galvanneal coatings, it is critical to control the reaction rate between solid iron and molten zinc.In commercial galvannealing line, aluminum is added to zinc bath to retard the diffusion rate between iron and zinc by the formation of a thin layer of Al intermetallic compound on the surface of steel at initial hot-dip galvanizing. However, the form of this compound and its transformation are still speculated. In this paper, we report the direct observations of this compound and its transformation.The specimens were prepared in a hot-dip simulator in which the steel was galvanized in the zinc bath containing 0.14 wt% of Al at a temperature of 480 °C for 5 seconds and was quenched by liquid nitrogen.


2009 ◽  
Vol 24 (9) ◽  
pp. 2880-2885 ◽  
Author(s):  
Jing Zhang ◽  
Wei Yan ◽  
Chenguang Bai ◽  
Fusheng Pan

Mg-Li-Al alloy was prepared by ingot casting and then underwent subsequent reactive ball milling. A Mg-Li-Al-H complex hydride was obtained under a 0.4 MPa hydrogen atmosphere at room temperature, and as high as 10.7 wt% hydrogen storage capacity was achieved, with the peak desorption temperature of the initial step at approximately 65 °C. The evolution of the reaction during milling, as well as the effect of Li/Al ratio in the raw materials on the desorption properties of the hydrides formed, were studied by x-ray diffraction and simultaneous thermogravimetry and differential scanning calorimetry techniques. The results showed that mechanical milling increases the solubility of Li in Mg, leading to the transformation of bcc β(Li) solid solution to hcp α(Mg) solid solution, the latter continues to incorporate Li and Al, which stimulates the formation of Mg-Li-Al-H hydride. A lower Li/Al ratio resulted in faster hydrogen desorption rate and a greater amount of hydrogen released at a low temperature range, but sacrificing total hydrogen storage capacity.


2018 ◽  
Vol 739 ◽  
pp. 518-521 ◽  
Author(s):  
C.L. Yang ◽  
S. Tsuda ◽  
K. Umeo ◽  
T. Onimaru ◽  
W. Paschinger ◽  
...  

2010 ◽  
Vol 152-153 ◽  
pp. 1607-1610 ◽  
Author(s):  
Wei Chan Cao ◽  
Shu Hua Liang ◽  
Yue Xin Xue ◽  
Xian Hui Wang

In order to gain a deep insight into the mechanism of Ni-doped Mo activated sintering process, the diffusion behavior of Mo-Ni interface was studied utilizing a Mo-Ni diffusion couple. The phase structure and composition on the diffusion layer were characterized and analyzed by means of scanning electron microscope and transmission electron microscope, the self diffusion coefficient and interdiffusion coefficient were calculated. The results show that a diffusion layer is formed between Mo and Ni after sintering at 1223k for 1h, which is comprised of a δ-NiMo intermetallic compound and a limit solid solution containing small amounts of nickel. The self diffusion coefficient and interdiffusion coefficient are 2.068×10-18cm2/s and 4.5×10-12cm2/s, respectively. It is suggested that the diffusion rate of Mo in δ-NiMo intermetallic compound and a limit solid solution containing small amounts of nickel is 106 times bigger than that of self diffusion, and the intermetallic compound layer provides a short diffusion path for Mo activated sintering.


2020 ◽  
Vol 9 (5) ◽  
pp. 11392-11401
Author(s):  
Yongpeng Zhuang ◽  
Pengwen Zhou ◽  
Hongxia Wang ◽  
Kaibo Nie ◽  
Yiming Liu ◽  
...  

2014 ◽  
Vol 1004-1005 ◽  
pp. 168-171
Author(s):  
Hong Yan Du ◽  
Yaj Jang Li ◽  
Juan Wang

Mg/Al dissimilar materials were welded successfully by GTAW with SAlMg-1 and SAlMg-2 welding wire of Mg-Al system. The nice weld shape and free defects of joints are obtained. The test results indicated that continuous lamellar intermetallic compounds is not found The structure of Mg side in the fusion zone is composed of α-Mg solid solution+ β-Al12Mg17eutectic structure and precipitates β-A112lMg17on the grain boundary. The structure in the weld zone is mainly α-Mg solid solution + β-A112lMg17solid solutions. Mg and Al content are stable in the fusion zone of Mg side. However, in the weld zone of Mg side the Mg content is decreased gradually, and the Al content is increased that reaches a stable level in the weld zone of Al side. As a result, when Mg content in the wire can hold a proper level, the intermetallic compounds will be controlled effectively, and the performance of AZ31/7005 welding joint can be improved.


2013 ◽  
Vol 631-632 ◽  
pp. 167-171
Author(s):  
Wei Xiang Zhang ◽  
Shuang Min Du

For effective bonding of Magnesium alloy, Cu foil was used as the interlayer to conduct the diffusion bonding experiment of AZ31B alloy. The microstructure and properties of the diffusion bonding joint was analyzed by means of SEM, EDS and micro-hardness tester. Experiment results show that compact bonding joint was obtained at the temperature of 480°C, holding time of 30 minutes, pressure of 10 MPa and the vacuum degree of 1.0×10-2Pa. The bonding joint consists of a interfacial diffusion region which is a mixture of Mg2Cu, MgCu2, and Mg(Cu) solid solution, and the transitional zone which is composed of Mg(Cu,Al) solid solution base and Mg17(Al, Cu)12 phase. Within the bonding joint,the micro-hardness shows a step pattern of increasing, which is well accord with the the microstructural feature of the joint.This trial has prove that using Cu as the interlayer is effective to improve the quality of the AZ31B bonding joint.


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