New type of spherical pore Al alloy foam with low porosity and high strength

Yi, Zhuangpeng; He, Dingxin; Jiang, Jiaqiao

doi:10.1007/bf02990901

Cited by 18 publications

(9 citation statements)

References 3 publications

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“…In this context, attentions have been paid to the metal foam with low porosity for larger effective thermal conductivity. With recent advances in processing technologies, closed‐cell metal foam with low porosity has been manufactured . According to References , the pore shape can be categorized into three groups for the closed‐cell metal foams, including sphere‐like pores, spherical pores, and polygonal pores (ie, square pores).…”

Section: Fractal Characterization Of Porous Structurementioning

confidence: 99%

“…With recent advances in processing technologies, closed‐cell metal foam with low porosity has been manufactured . According to References , the pore shape can be categorized into three groups for the closed‐cell metal foams, including sphere‐like pores, spherical pores, and polygonal pores (ie, square pores). Moreover, the results of pioneering work by Zhang et al indicate that, despite the deficiency of time delay in the solidification front, the solidification behavior can be well predicted based on the assumption that a two dimensional (2D) square is applied for the description of the pore shape of the metal foam.…”

Section: Fractal Characterization Of Porous Structurementioning

confidence: 99%

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Role of metal foam in solidification performance for a latent heat storage unit

Huang

Zhang

2019

Int J Energy Res

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Summary The current latent heat storage (LHS) units are usually poor in energy charging and discharging efficiency. Given this, a two dimensional (2D) numerical model of the energy discharging process is presented and comprehensively analyzed to predict the role of metal foam in the solidification performance of LHS units. In the model, the fractal geometry reconstructed by the fractal Brownian motion is utilized for the pore characterization of the metal foam. The proposed model is validated through a melting experiment in copper foams from the reference. The temperature dynamic response and the solidification front evolution in metal foam are analyzed and compared to those in a corresponding cavity. The roles of the fractal dimension and porosity in the solidification behaviors are quantitatively analyzed. The results report that the presence of metal foam enhances the solidification performance. For the main goal of maximizing the latent storage, the appropriate porosity of an LHS unit is dependent on the duration time for the heat discharging process in the real application of thermal energy storage. Even if the porosity is the same, the fractal dimension also affects the solidification performance. A decrease in the fractal dimension (lower degree of disorder for pore distribution) provides greater access to heat flow through the phase change material‐foam composite and thus leads to improvement in the interstitial heat transfer, which in turn accelerates the rate of heat release. The fractal dimension is expected to be less than 1.5 for superior solidification performance.

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Section: Fractal Characterization Of Porous Structurementioning

confidence: 99%

Section: Fractal Characterization Of Porous Structurementioning

confidence: 99%

Role of metal foam in solidification performance for a latent heat storage unit

Huang

Zhang

2019

Int J Energy Res

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“…With recent advances in processing technologies, aluminum foams with high porosities and small polygonal pores (Zone II, Figure 2) [16] or (relatively low) low porosities and spherical pores (Zone III and Zone IV, Figure 2) [17,18] have been manufactured. Therefore, for a close-celled aluminum foam, the pore shape can be categorized into three groups according to the porosity of the foam (denoted here as ε): Spherical pores, spherelike pores, and polygonal pores.…”

Section: Processing Of Close-celled Metallic Foams: Control Of Pore Mmentioning

confidence: 99%

“…It can be concluded from Figure 2 that if the pore size and porosity of close-celled aluminum foam are fixed, its pore shape is determined accordingly. It has been established that close-celled metallic foams with different pore morphologies also exhibit different load-bearing and energy-absorbing properties [17,18] . For instance, it was found experimentally that closecelled Al alloy foams with spherical pores have superior energy absorption properties in comparison with foams having polygonal pores; see Figure 3 [18] .…”

Section: Processing Of Close-celled Metallic Foams: Control Of Pore Mmentioning

confidence: 99%

The solidification of two-phase heterogeneous materials: Theory versus experiment

Zhang

Kim

2009

Sci. China Ser. E-Technol. Sci.

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The solidification behavior of two-phase heterogeneous materials such as close-celled aluminum foams was analytically studied. The proposed analytical model can precisely predict the location of solidification front as well as the full solidification time for a two-phase heterogeneous material composed of aluminum melt and non-conducting air pores. Experiments using distilled water simulating the aluminum melt to be solidified (frozen) were subsequently conducted to validate the analytical model for two selected porosities (ε), ε=0 and 0.5. Full numerical simulations with the method of finite difference were also performed to examine the influence of pore shape on solidification. The remarkable agreement between theory and experiment suggests that the delay of solidification in the two-phase heterogeneous material is mainly caused by the reduction of bulk thermal conductivity due to the presence of pores, as this is the sole mechanism accounted for by the analytical model for solidification in a porous medium. effective thermal conductivity, porous materials, solidification, shape factor

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“…[8,9] If the cell deformation and failure can be predicted by the initial cell structure, an optimized direction of foam structure could be provided for preparation, and then, the mechanical properties could be improved. [10][11][12] Moreover, the first failure region of an aluminum foam piece could be known in advance [13] and prevented through reinforcement, which is significant for applications.…”

Section: Introductionmentioning

confidence: 99%

Study on Cell Deformation of Low Porosity Aluminum Foams under Quasi‐Static Compression by X‐Ray Tomography

et al. 2020

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Understanding the correlation between cell deformation and initial cell structure during compression is important for improvement and development of effective applications of aluminum foams. Foams with porosities lower than 75% now get more attention because of more spherical cells and better mechanical performance. Herein, two low porosity aluminum foam samples are deformed by a compressive device allowing simultaneous X‐ray tomography. The foam cell structures in the initial undeformed state and in the state, where the first batch of cells deforms, are characterized and correlated. The absolute value of anisotropy change is selected as the most sensitive parameter to evaluate the cell deformation. A fitting formula between the cell deformation degree and the initial cell parameters is obtained, which can predict the cell deformation degree. It is found that a cell with small anisotropy, large angle between the longest axis of the cell and the loading direction, small sphericity, more neighbors, and large cell size is more prone to deform during compression. With the fitting formula, the weakest region where the first batch of deformed cells occurs can be predicted. The influence of cell morphology parameters in low porosity aluminum foams is significant and verified by experimental results.

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New type of spherical pore Al alloy foam with low porosity and high strength

Cited by 18 publications

References 3 publications

Role of metal foam in solidification performance for a latent heat storage unit

Role of metal foam in solidification performance for a latent heat storage unit

The solidification of two-phase heterogeneous materials: Theory versus experiment

Study on Cell Deformation of Low Porosity Aluminum Foams under Quasi‐Static Compression by X‐Ray Tomography

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