scholarly journals A-242 Aluminium Alloy Foams Manufacture from the Recycling of Beverage Cans

Metals ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 92 ◽  
Author(s):  
Nallely Trejo Rivera ◽  
Jesús Torres Torres ◽  
Alfredo Flores Valdés
Keyword(s):  
Aluminium Alloy ◽  
Titanium Hydride ◽  
Experimental Parameter ◽  
Melting Process ◽  
Molten State ◽  
Commercial Purity ◽  
Average Porosity ◽  
Different Temperatures ◽  
Parameter Values ◽  
Average Relative Density

This paper presents and discusses a methodology implemented to study the process of the preparation of aluminium alloy foams using the alloy A-242, beginning from the recycling of secondary aluminium obtained from beverage cans. The foams are prepared by a melting process by adding 0.50 wt.% calcium to the A-242 aluminium alloy with the aim to change its viscosity in the molten state. To obtain the foam, titanium hydride is added in different concentrations (0.50 wt.%, 0.75 wt.%, and 1.00 wt.%) and at different temperatures (923, 948 K, and 973 K) while the foaming time is kept constant at 30 s. For a set of experimental parameter values, aluminium alloy foams with the average relative density of 0.12 were obtained and had an 88.22% average porosity. In this way, it is possible to state that the preparation of aluminium alloy foams A-242 processed from the recycling of cans is possible, with characteristics and properties similar to those obtained using commercial-purity metals.

scholarly journals A Logistic Approach for Kinetics of Isothermal Pyrolysis of Cellulose

Processes ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 551
Author(s):  
Jorge López-Beceiro ◽  
Ana María Díaz-Díaz ◽  
Ana Álvarez-García ◽  
Javier Tarrío-Saavedra ◽  
Salvador Naya ◽  
...  
Keyword(s):  
Kinetic Model ◽  
Time Derivative ◽  
Inert Atmosphere ◽  
Second Step ◽  
Rate Parameter ◽  
Thermogravimetric Data ◽  
Different Temperatures ◽  
Parameter Values ◽  
Kinetics Of ◽  
Logistic Functions

A kinetic model is proposed to fit isothermal thermogravimetric data obtained from cellulose in an inert atmosphere at different temperatures. The method used here to evaluate the model involves two steps: (1) fitting of single time-derivative thermogravimetric curves (DTG) obtained at different temperatures versus time, and (2) fitting of the rate parameter values obtained at different temperatures versus temperature. The first step makes use of derivative of logistic functions. For the second step, the dependence of the rate factor on temperature is evaluated. That separation of the curve fitting from the analysis of the rate factor resulted to be very flexible since it proved to work for previous crystallization studies and now for thermal degradation of cellulose.

Background subtraction and moments of the microscopic density fluctuation

2002 ◽  
Vol 35 (2) ◽  
pp. 220-227 ◽  
Author(s):  
Roger Sobry ◽  
Salvino Ciccariello
Keyword(s):  
Background Subtraction ◽  
Density Fluctuation ◽  
Density Fluctuations ◽  
Algebraic Expression ◽  
Real Samples ◽  
Background Contribution ◽  
X Ray ◽  
Different Temperatures ◽  
Parameter Values ◽  
Best Fit

Some models of microscopic density fluctuations are numerically analysed in order to study the behaviour of the related background contribution. The results suggest that this contribution can be described by an algebraic expression depending on only the moments of the microscopic density fluctuation. In this way, the parameter values, determined by a best-fit procedure to account for background contributions in the case of real samples, acquire a definite physical meaning. The procedure is applied to the small-angle X-ray intensities of a polymer sample analysed at different temperatures and yields satisfactory results.

scholarly journals Hydration Features of Composite Binding Material with High-Dose Copper Tailings

2021 ◽  
Vol 45 (1) ◽  
pp. 17-24
Author(s):  
Yang Wang ◽  
Hanxi Wang ◽  
Linwei Yang ◽  
Li Qian
Keyword(s):  
Hydration Process ◽  
High Dose ◽  
Mass Concrete ◽  
Copper Tailings ◽  
Granulated Blast Furnace Slag ◽  
Binding Material ◽  
Different Temperatures ◽  
Hydration Model ◽  
Center Particle ◽  
Parameter Values

Based on Krstulovic-Dabic model, this paper modifies the center particle hydration model according to the features of copper tailings, and then simulates the hydration process of cement-based composite binding system mixed with copper tailings. The hydration exothermic features were analyzed under different dosages, and different temperatures. Then, the simulated parameter values of the hydration process were compared with those measured in experiments. The results show that: the mixing of copper tailings powder can reduce the hydration heat release and slow down hydration rate of the composite binding material, and improve the thermal performance of the concrete; the prepared copper tailings powder is active enough to replace fly ash and ground-granulated blast furnace slag (GGBS) as cement admixtures; When the dosage surpasses 40%, the copper tailings can be applied to mass concrete projects.

Hydrogen Release from Oxidized Titanium Hydride

2018 ◽  
Vol 941 ◽  
pp. 2203-2208 ◽  
Author(s):  
Marco Gambini ◽  
Roberto Montanari ◽  
Maria Richetta ◽  
Tommaso Stilo ◽  
Alessandra Varone ◽  
...  
Keyword(s):  
Titanium Hydride ◽  
Specific Treatment ◽  
Critical Issue ◽  
Industrial Applications ◽  
Hydrogen Release ◽  
X Ray Diffraction ◽  
Residual Hydrogen ◽  
Different Temperatures ◽  
Higher Temperature ◽  
Temperature Programmed

Hydrogen storage is one of the most important industrial applications of titanium hydride (TiH2). A critical issue is the hydrogen release rate that strongly depends on the surface structure of TiH2 particles. This work reports the results of an experimental campaign carried out on TiH2 powders submitted to heat treatments in air at different temperatures and treatment times. After each heat treatment the TiH2 powders were examined by X-ray diffraction (XRD) and the results evidenced that the surface layer consists of TiO2 and Ti2O. Titanium oxide formation has been monitored by XRD at high temperature. Hydrogen release during heating of oxidized powders was investigated through temperature programmed desorption (TPD). Residual hydrogen in TiH2 depends on the specific treatment: higher temperature and soaking time of the treatment, lower its content.

Mechanical Behaviour of an AA6082 Aluminium Alloy at Low Temperatures

2014 ◽  
Vol 794-796 ◽  
pp. 532-537 ◽  
Author(s):  
Ida Westermann ◽  
Odd Sture Hopperstad ◽  
Magnus Langseth
Keyword(s):  
Aluminium Alloy ◽  
Work Hardening ◽  
Aluminium Alloys ◽  
Room Temperature ◽  
Area Reduction ◽  
Work Hardening Rate ◽  
Different Temperatures ◽  
Tensile Data ◽  
Initial Work ◽  
Marine Applications

Aluminium alloys are known to have good cryogenic properties. However, little work is reported on aluminium alloys in the temperature range from room temperature and down to-100°C, which are likely operating temperatures in arctic regions. This work is an experimental study of the low temperature mechanical properties of an extruded AA6082 aluminium alloy in the T6 condition approved for marine applications. Quasi-static and dynamic tensile testing has been carried out at different temperatures from room temperature and down to-70°C. This decrease in temperature leads to a 10 % increase in yield strength. No significant influence of temperature was found on the area reduction to fracture. The work-hardening behaviour has been analysed for different temperatures and strain rates by fitting a generalized Voce rule to the tensile data. The initial work-hardening rate is found to depend weakly on the temperature and strain rate.

Evaluation of Fracture Energy of Aluminium Alloy 1050-F and Carbon Steel EN - 3 (~1015) 0.15% C at Different Temperatures Gradient

2021 ◽  
pp. 150-168
Author(s):  
O. M. Ikumapayi ◽  
E. T. Akinlabi ◽  
S. O. Fatoba ◽  
R. A. Kazeem ◽  
S. O. Afolabi ◽  
...  
Keyword(s):  
Carbon Steel ◽  
Fracture Energy ◽  
Aluminium Alloy ◽  
Different Temperatures
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