The stability of aluminum foams at accumulation and condensation stages in gas injection foaming process

2015 ◽  
Vol 482 ◽  
pp. 468-476 ◽  
Author(s):  
Yutong Zhou ◽  
Yanxiang Li ◽  
Jianyu Yuan
Keyword(s):  
Gas Injection ◽  
Aluminum Foams ◽  
Foaming Process ◽  
The Stability

Comparison of Cell Wall Microstructure of Aluminum Foams Produced by Melt Foaming and Gas Injection Foaming Processes

2013 ◽  
Vol 457-458 ◽  
pp. 540-543
Author(s):  
Yu Tong Zhou ◽  
Yan Xiang Li ◽  
Xing Nan Liu ◽  
Wen Wen Yuan
Keyword(s):  
Cell Wall ◽  
Cell Walls ◽  
Base Alloy ◽  
Gas Injection ◽  
Secondary Phases ◽  
Practical Application ◽  
Aluminum Foams ◽  
Foaming Process ◽  
Metallurgical Structure ◽  
The Difference

Aluminum foams from A356 base alloy were produced by both the melt foaming process and gas injection foaming process. A comparison of microstructures between the two kinds of aluminum foams was carried out. The related causes were analyzed to form the difference in microstructure. Results indicate that aluminum foams produced by different processes are distinct in metallurgical structure. The average thickness of cell wall, the species and area fraction of secondary phases or particles and other metallurgical features have been all comparatively studied. The difference in microstructure features of the cell walls will also make the aluminum foams different in mechanical properties. Therefore, we need to select proper foaming process for aluminum foams according to the property requirements in practical application.

The Structure and Acoustic Properties of Aluminum Foams by Gas Injection Method

2010 ◽  
Vol 146-147 ◽  
pp. 1049-1055
Author(s):  
Xue Liu Fan ◽  
Xiang Chen ◽  
Yan Xiang Li
Keyword(s):  
Sound Absorption ◽  
Gas Injection ◽  
Optical Microscope ◽  
Absorption Efficiency ◽  
Absorption Capacity ◽  
Acoustic Properties ◽  
Analytical Models ◽  
Aluminum Foams ◽  
Injection Method ◽  
Membrane Vibrations

The acoustic properties of aluminum foams by gas injection method were studied experimentally. The micro and macro structure of aluminum foam with closed cells were observed by optical microscope (OM) and scanning electron microscope (SEM). The special structure of the closed-pores of the aluminum foams have leaded to good performance of the sound absorption based on three mechanisms: Helmholtz resonance, cell wall vibration and viscous and thermal effects. The effect of cell sizes, thickness of aluminum foams has been investigated and the cavity set at the back of the foam samples on the sound absorption efficiency of the foams has been measured. Analytical models of membrane vibrations were used to explain the sound absorption capacity of the foams.

Technology and Effectiveness of Cast Iron Treatment by Gas Injection

2010 ◽  
Vol 457 ◽  
pp. 459-464
Author(s):  
Edis B. Ten
Keyword(s):  
Cast Iron ◽  
Gas Injection ◽  
Small Diameter ◽  
Multiple Use ◽  
Positive Effects ◽  
Injection Treatment ◽  
The Stability ◽  
Injection Technology ◽  
Stability Regime ◽  
Structure Stabilization

In this work the development of the technology and equipment for gas injection treatment of cast iron by inert gas (nitrogen) is presented. The equipment includes the plunging lance as a lined steel pipe with nozzles. The nozzles are thin channels, which are lined by ceramic tubes with small-diameter. The lance has a multiple use, as it has calibrated channel sizes, and provide the stability regime of gas injection treatment. The characteristic of the gas injection technology consists of blowing of melt by gas, which is injected into the liquid cast iron through thin jet with a speed near to the velocity of sound. In this case, the dispersion of gas jets in small-sized bubbles is reached, therefore the refining effectiveness increases. The gas injection treatment shows the promotion of casting properties, improvement of homogeneity and fineness of structure, stabilization or increasing of mechanical properties, decreasing of casting defectiveness. The positive effects of the gas injection treatment is the result of complex action of the injecting gas into the cast iron melt. Together with refining and homogenizing action at specified conditions, it offers the modifying and alloying effects also.

scholarly journals Anisotropic Compressive Behavior of Functionally Density Graded Aluminum Foam Prepared by Controlled Melt Foaming Process

Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2470 ◽  
Author(s):  
Bingbing Zhang ◽  
Shuangqi Hu ◽  
Zhiqiang Fan
Keyword(s):  
Energy Absorption ◽  
Aluminum Foam ◽  
Image Correlation ◽  
Lateral Strain ◽  
Transverse Compression ◽  
Deformation Bands ◽  
Aluminum Foams ◽  
Static Compression ◽  
Plateau Stress ◽  
Foaming Process

Aluminum foams with a functionally graded density have exhibited better impact resistance and a better energy absorbing performance than aluminum foams with a uniform density. Nevertheless, the anisotropic compression behavior caused by the graded density has scarcely been studied. In this paper, a density graded aluminum foam (FG) was prepared by a controlled foaming process. The effect of density anisotropy on the mechanical behavior of FGs was investigated under quasi-static compression and a low-velocity impact. Digital image correlation (DIC) and numerical simulation techniques were used to identify deformation mechanisms at both macro and cell levels. Results show that transverse compression on FGs lead to a higher collapse strength but also to a lower energy absorption, due to the significant decrease in densification strain and plateau stress. The deformation behavior of FGs under longitudinal compression was dominated by the progressive extension of the deformation bands. For FGs under transverse compression, the failure mode of specimens was characterized by multiple randomly distributed deformation bands. Moreover, the transverse compression caused more deformation on cells, through tearing and lateral stretching, because of the high lateral strain level in the specimens. It was concluded that the transverse compression of FGs lead to a lower plateau stress and a lower cell usage, thus resulting in a poorer energy absorption efficient; this constitutes a key factor which should be taken into consideration in structural design.

Stability of Gas Injection Using Lateral Wells in Layered Oil Reservoirs

2007 ◽  
Vol 18-19 ◽  
pp. 271-276
Author(s):  
E. Steve Adewole ◽  
B.M. Rai
Keyword(s):  
Pressure Distribution ◽  
Gas Injection ◽  
Oil Production ◽  
Bottom Layer ◽  
Oil Reservoirs ◽  
Mobility Ratio ◽  
Fluid Velocities ◽  
The Stability ◽  
Gas Cycling ◽  
Gas Properties

The stability of gas injection in a layered reservoir drilled with lateral wells, is studied using a generalized pressure distribution-dependent mobility ratio expression. Stable injection guarantees clean oil production. The mobility ratio compared layers’ fluid velocities across a common permeable interface. Studies were based on injected gas compressibilities and viscosities only. Results show that injection stability is affected by (1) injected gas properties, and (2) injection layer; i.e., whether gas cycling (bottom layer injection) or gas injection (top layer injection). Gas cycling tends to exhibit more instability than gas injection operation.

Preparation and characterization of a fly ash and cement-based foam composite

2020 ◽  
Vol 10 (10) ◽  
pp. 1758-1763
Author(s):  
Liang Zhao ◽  
Qian Huang ◽  
Qunhu Xue ◽  
Shuang Yao ◽  
Xiang Li
Keyword(s):  
Fly Ash ◽  
Glass Fiber ◽  
Raw Materials ◽  
Dry Density ◽  
Rosin Soap ◽  
Foaming Process ◽  
Reinforcing Agent ◽  
Foam Composite ◽  
The Stability

Industrial waste fly ash and ordinary Portland cement (PO42.5) were used as the main raw materials, Ca(OH)2 as the alkali activator, modified rosin soap as the foaming agent, and glass fiber as the reinforcing agent. A physical foaming technology was chosen to fabricate a fly ash and cement-based foam composite. The effects of water-to-binder (W/B) ratio and glass fiber addition on the performance of the foam composite were studied. The structure formation and reinforcement mechanism of the foam composite were discussed, and the optimal formulation was determined, which provides a new technical approach to utilize fly ash and improve the strength and reliability of foam cement products. The results show that different water-to-binder ratios directly affect the stability of the pores during the foaming process, and the glass fiber has a protective effect on the foam. When the W/B ratio is 0.5, meanwhile the addition of glass fiber is 1.5%, the fly ash and cement-based foam composite can achieve better physical performance: the dry density is 368 kg/m3, the water absorption rate is 39.12%, and the 28-day compressive strength is increased by 86.31% (reaching 3.47 MPa) compared to that of the sample without a glass fiber.

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