Microstructure control and strengthening mechanism of fine-grained cast Mg alloys based on grain boundary segregation of Al solute

Lin, Xiaoping; Dang, Yuzhen; Dai, Penglin; Fang, Daran; Xu, Chunxiang; Wen, Bin

doi:10.1016/j.msea.2022.143665

Cited by 13 publications

(2 citation statements)

References 21 publications

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“…Therefore, the shear strength of the joints was effectively improved. It is well known that grain boundary strengthening is an important method to impede crack propagation and improve the mechanical property of joints [27][28][29][30][31][32][33][34][35]. In addition, for p-SiO 2 joints brazed with the Ag-1.0 mol% CuO filler metal, the fluidity of the filler metal was improved and all the filler metal infiltrated into the p-SiO 2 ceramic, as shown in Figure 10c.…”

Section: The Interfacial Formation Mechanism Of P-sio2 Jointmentioning

confidence: 92%

Study on Reactive Air Brazing of p-SiO2 Ceramic with Ag-xCuO Filler Metal

Chen,

Ma,

2023

Metals

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Reactive air brazing of porous SiO2 ceramic (p-SiO2) was achieved using Ag-CuO filler metal. When brazing p-SiO2, two main problems existed. Firstly, the wettability of the Ag filler metal on the surface of p-SiO2 was poor. Secondly, the residual stress caused by the mismatch of the coefficient of thermal expansion was high in the joint. In order to solve these problems, the effects of CuO contents on the p-SiO2 brazed joint were analyzed. In a wetting experiment, the addition of CuO significantly improved the wettability of the Ag-CuO/p-SiO2 system. With the content of CuO increasing, the contact angle decreased from 90° to 0°. In addition, when the content of CuO increased to 0.5 mol%, the contact angle decreased from 90° to 52°. Then, during brazing p-SiO2 with the Ag-xCuO filler metal, the typical interfacial microstructure of the joints brazed at 1000 °C for 30 min was p-SiO2 ceramic/Ag (s,s) + SiO2 + CuO/Ag (s,s)/Ag (s,s) + SiO2 + CuO/p-SiO2 ceramic. Meanwhile, Ag-CuO infiltrated into the p-SiO2 ceramic and an infiltration layer formed. The infiltration layer was composed of Ag (s,s) + SiO2 + CuO and the infiltration layer was conductive to form a good gradient transition of the coefficient of thermal expansion (CTE). Then, the residual stress in the joint was released and the shear strength improved. In addition, with the content of CuO increasing, the depth of the infiltration layer increased. Furthermore, when the content of CuO was 0.5 mol%, the maximum shear strength of the joint was 55 MPa.

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Section: The Interfacial Formation Mechanism Of P-sio2 Jointmentioning

confidence: 92%

Study on Reactive Air Brazing of p-SiO2 Ceramic with Ag-xCuO Filler Metal

Chen,

Ma,

2023

Metals

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“…It is well known that solute segregation at grain boundaries is an effective route to control and inhibit grain growth at high temperatures, including magnesium alloys. [ 18 ] Segregates have been found in relatively thick films between the bulk grains of as‐cast AZ31 alloy [ 19 ] and our recent in situ study on the same AZ91 sheet material as employed in this article reported on the dissolution of Al 12 Mg 17 intermetallics, leading to concentration gradients and the interdiffusion of surplus Al from the outer grain perimeters to the center. [ 8 ] It is evident that segregation or even intermetallic compounds at grain boundaries must be dissolved before diffusive channels open, allowing for grain rotation.…”

Section: Underpinning Models Leading To the Interpretation Of Activat...mentioning

confidence: 95%

Abnormal Grain Growth: A Spontaneous Activation of Competing Grain Rotation

Liss,

Xu,

Shiro

et al. 2023

Adv Eng Mater

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Unconventional white‐beam Laue synchrotron X‐ray diffraction has been used on fine‐grained, rolled magnesium alloy during an in‐situ heating experiment. At high temperatures, reflections of single grains are superimposed on the halo stemming from matrix grains. Some unique grain reflections spontaneously move, indicating grain rotations in response to torque expedited at grain boundaries. When a grain boundary spontaneously activates, it can begin to rotate, allowing diffusive mass transport and activating the boundaries of its other neighbors. Now the given grain can freely rotate towards coalescence; however, the multitude of grain boundaries compete in torque orientation and magnitude, resulting in zigzag rotations. After coalescence, the larger grain is still active and continues this scenario of growth, while the majority of the matrix grains remain inactive. The first‐time experimental observation of such erratic grain behavior supplies the missing puzzle stone leading to anomalous grain growth, long postulated in literature. The method of white‐beam Laue diffraction on fine‐grained polycrystalline materials delivers a novel experimental method to study the erratic behavior of grain reorientation, as requested long ago by the scientific community. Such findings apply to wide ranges of materials undergoing grain growth, creep, and superplasticity, including those in metal engineering, ceramics, and geo‐physical disciplines.This article is protected by copyright. All rights reserved.

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Microstructure and mechanical properties of extruded Mg-6Al-2X (X = Cu/Ni/Fe) alloy used degradable bridge plugs

Liu,

Zhang

et al. 2023

Adv Compos Hybrid Mater

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Microstructure control and strengthening mechanism of fine-grained cast Mg alloys based on grain boundary segregation of Al solute

Cited by 13 publications

References 21 publications

Study on Reactive Air Brazing of p-SiO2 Ceramic with Ag-xCuO Filler Metal

Study on Reactive Air Brazing of p-SiO2 Ceramic with Ag-xCuO Filler Metal

Abnormal Grain Growth: A Spontaneous Activation of Competing Grain Rotation

Microstructure and mechanical properties of extruded Mg-6Al-2X (X = Cu/Ni/Fe) alloy used degradable bridge plugs

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