Production Techniques of Metallic Foams in Lightweight Materials

2022 ◽  
pp. 153-175
Author(s):  
Nuray Beköz Üllen ◽  
Gizem Karabulut

Lightweight materials were needed in many different areas, especially in order to reduce the required energy in areas such as automotive and aerospace industries. Metallic foams attract attention in lightweight material applications due to their unique properties. The pores in its structure provide advantages in many applications, both structural and functional by promising both ultra-lightweight construction, energy absorption, and damping insulation. Production techniques of metallic foams can generally be classified as liquid, solid, gas, and ionic state production according to the physical state of the metal at the beginning of the process. The production technique should be chosen according to the usage area and desired properties of the metallic foam and the suitability in terms of cost and sustainability of production. For this reason, the details of the production techniques should be known and the products that can be obtained and their properties should be understood. In this respect, this chapter emphasizes the production methods from past to present.

1997 ◽  
Vol 1997 ◽  
pp. 196-196
Author(s):  
S. Fakhri ◽  
A. R. Moss ◽  
D.I. Givens ◽  
E. Owen

Recently, the automatic in vitro gas production techniques (e.g. Cone. 1994; Theodorou et al., 1994) have been developed to study rumen fermentation kinetics. Many approaches have been taken. This work investigates the suitability of different methods for estimating the rumen fermentation of two starch rich feedstuffs.


This chapter deals with data production within the paradox of big-no data in urban logistics. More precisely, the chapter aims to make an overview on data production in urban logistics and present the main issues, as well as a framework, to overcome that paradox. First, the big-no data paradox is defined and motivated. Second, the question of demand and route estimation in urban logistics is examined more in-depth via an overview of current data production methods and techniques used to estimate demand and transport flows. Third, a framework to produce unified databases filling those data lacks is introduced as well as an analysis on how the different data production techniques can be used to overcome that paradox. Finally, research directions regarding urban goods transport data production are provided.


2009 ◽  
Vol 2009 ◽  
pp. 190-190
Author(s):  
A Taghizadeh ◽  
M Besharati

Anaerobic digestion of carbohydrates by ruminal microbes produces short chain fatty acids (SCFA), CO2, CH4, and traces of H2; hence, measurement of gas production in vitro can be used to study the rate and extent of digestion of feedstuffs (Hungate, 1966). When a feedstuff is incubated with buffered rumen fluid in vitro, the carbohydrates are fermented to SCFA, gases mainly CO2 and CH4 and microbial cells. Gas production is basically the result of fermentation of carbohydrates to acetate, propionate and butyrate (Wolin, 1960; Beuvink and Spoelstra, 1992; Blummel and Ørskov, 1993). High correlations between gas production and NDF disappearance, r2 = 0.99 (Pell and Schofield, 1993) or gas production and DM disappearance, r2 = 0.95 (Prasad et al., 1994) have been reported. In vitro techniques that estimate digestion kinetics indirectly by measuring gas production are a more viable option than other in vitro methods. Gas production technology allows for a more usable collection of digestion kinetics data and has allowed for a growing body of knowledge that is directly applicable to the feeding programs that are in daily practical field use. The range of data that can be acquired is broad and will no doubt grow over time. One of the most challenging problems associated with using gas production methods is that the amount of gas produced varies with different molar proportions of SCFA. For example, a higher propionate concentration is associated with lower gas production because an extra carbon atom in propionate would otherwise have appeared as CO2 (Wolin, 1960). The object of this study was to evaluate the nutritional quality of noodle waste (NW), tomato pomace (TP) and apple pomace (AP) using the gas production technique.


1998 ◽  
Vol 22 ◽  
pp. 172-174
Author(s):  
D. L. Romney ◽  
F. C. Cadario ◽  
E. Owen ◽  
A .H. Murray

Parameters from in vitro gas production techniques could have potential as predictors of dry-matter intake (DMI) and digestibility. Fermentation is usually carried out under conditions where nitrogen (N) is not limiting. Therefore where N supply is a constraint to intake and digestibility, prediction equations may be inaccurate. This study compared the use of N-free and N-rich media in an in vitro fermentation method (Theodorou et al., 1994) and studied the relationships between in vitro and in vivo parameters obtained using both media.


2018 ◽  
Vol 21 (14) ◽  
pp. 2081-2098 ◽  
Author(s):  
Jinhua Zhang ◽  
Yadong Zhang ◽  
Junyu Fan ◽  
Qin Fang ◽  
Yuan Long

This article is aimed to reveal the dynamic response of layered graded metallic foam under impact loading using a three-dimensional mesoscopic model. First, a mesoscopic model for closed-cell metallic foam is proposed based on the X-ray computed tomography images. Second, a numerical analysis approach is presented and validated with test data. Third, it studies the dynamic behavior of the layered graded metallic foam under impact loading numerically. The metallic foam specimen is composed layer by layer. The porosity, which is a fraction of the voids volume over the total volume, is different with each other for the layers. Simulations are conducted to the specimen with increasing and decreasing porosity arrangement. Results show that the layer arrangement is critical to the dynamic properties. The mesoscopic deformation of cell walls and the energy absorption capability are also affected significantly. This article gives insights into the mechanical properties and mesoscopic deformation of layered graded metallic foam.


Coatings ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 819
Author(s):  
Renáta Oriňaková ◽  
Radka Gorejová ◽  
Zuzana Orságová Králová ◽  
Andrej Oriňak

Significant progress was achieved presently in the development of metallic foam-like materials improved by biocompatible coatings. Material properties of the iron, magnesium, zinc, and their alloys are promising for their uses in medical applications, especially for orthopedic and bone tissue purposes. Current processing technologies and a variety of modifications of the surface and composition facilitate the design of adjusted medical devices with desirable mechanical, morphological, and functional properties. This article reviews the recent progress in the design of advanced degradable metallic biomaterials perfected by different coatings: polymer, inorganic ceramic, and metallic. Appropriate coating of metallic foams could improve the biocompatibility, osteogenesis, and bone tissue-bonding properties. In this paper, a comprehensive review of different coating types used for the enhancement of one or several properties of biodegradable porous implants is given. An outline of the conventional preparation methods of metallic foams and a brief overview of different alloys for medical applications are also provided. In addition, current challenges and future research directions of processing and surface modifications of biodegradable metallic foams for medical applications are suggested.


1998 ◽  
Vol 521 ◽  
Author(s):  
J. Banhart ◽  
J. Baumeister

ABSTRACTThe possibilities for making metallic foams or similar porous metal structures are reviewed. The various processes are classified according to the state of the starting metal - liquid, powdered, ionised. Liquid metal can be foamed directly by injecting gas, gas-releasing foaming agents or by producing supersaturated metal-gas solutions. Indirect methods include investment casting and usage of filler materials. Metal powders can also be used as starting materials for metallic foams: mixtures of such powders with foaming agents are compacted to foamable precursor materials that can be foamed in a second step. Instead of foaming agents inert gas can be directly entrapped in the precursor. Metal foams can also be made from metal powder slurries or by using polymer/powder mixtures. Finally, galvanic electro-deposition also allows to make highly porous metallic structures with open pores.


1998 ◽  
Vol 22 ◽  
pp. 247-248
Author(s):  
S. López ◽  
M. D. Carro ◽  
C. Valdés ◽  
J. S. González ◽  
F. J. Ovejero

Quantitative expressions of the kinetics of digestion are needed to estimate more precisely the quantity and composition of nutrients digested from feeds and their subsequent efficiency of utilization by the animal (Mertens, 1993). Degradation kinetic parameters are estimated by fitting appropriate models to data resulting from the measurement of either the undigested residue or the fermentation end-products after exposure of the feed to digestion. Kinetic data can be collected using either in vitro or in situ procedures. The in situ porous synthetic fibre bag technique has been extensively used to describe the kinetics of feeds degradation in the rumen. Several in vitro gas production methods have been developed to assess fermentation kinetics. The aim of this work was to study the relationship between rumen degradation parameters of forages determined either by the in situ procedure or by the gas production technique and to evaluate the potential of gas production measurements to assess the extent of dry matter degradation in the rumen.


Author(s):  
Shawn VanCour

The opening decades of the twentieth century witnessed a profound transformation in the history of modern sound media, with workers in US film, radio, and record industries developing pioneering production methods and performance styles tailored to emerging technologies of electric sound reproduction that directly shaped dominant forms and experiences of modern sound culture. Focusing on broadcasting’s initial expansion period during the 1920s, Making Radio explores the forms of creative labor pursued for the medium before the better-known network era of the 1930s and 1940s, assessing their role in shaping radio’s own identity and identifying affinities with parallel practices pursued for conversion-era film and phonography. Tracing programming forms adopted by early radio writers and programmers, production techniques developed by studio engineers, and performance styles cultivated by on-air talent, it shows how radio workers negotiated a series of broader industrial and cultural pressures to establish best practices for their medium. In the process, it argues, these sound workers shaped not only the future of broadcasting, but also contributed to much broader shifts in popular forms of music, drama, and public oratory, ushering in a new era of electric sound entertainment.


2016 ◽  
Vol 9 (1) ◽  
pp. 1
Author(s):  
Zahra Pakzad

Written manuscripts and literary treatises are among the most important documents of knowledge on traditional color production techniques related to painting, and as they have survived thanks to desirable maintenance and preservation from the ancient times to the present time, they can be good sources for identifying and extracting traditional color production methods related to paining. Especially, the illustrated books simultaneously with their writing are an evidence of the contents presented in those manuscripts and treatises. Therefore, by an aim to identify and revive traditional color production techniques, the present descriptive-analytic research examines some of the available handwritten manuscripts and literary treatises. Then, with emphasis placed on the knowledge acquired and the modern facilities, some of the colors are made. The present study was performed by raising the major question that what ancient literary books are the sources of production colors used in Persian painting, and what were the nature of color production techniques and traditional color characteristics in the past. Thus, the study population includes Golestan Honar, Qanun al-Sovar, Majmoueh al-Sanaye’ and 14 other treatises relevant to this issue, and the data collection was performed in a library- and experimental-based manner. The result of this study was the extraction, preparation and remaking of seven main mineral colors in Persian painting.


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