scholarly journals The Effect of Short Time Thermal Treatment on Swelling of Field Maple (Acer campestre L.) and Fir (Abies alba Mill.)

2020 ◽  
Vol 68 (3) ◽  
pp. 483-490
Author(s):  
Holta Çota ◽  
Leonidha Peri ◽  
Entela Lato ◽  
Hektor Thoma ◽  
Doklea Quku ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Thermal Treatment ◽  
Mass Loss ◽  
Abies Alba ◽  
Untreated Wood ◽  
Wood Industry ◽  
Time Duration ◽  
Acer Campestre ◽  
Different Temperatures ◽  
Short Time

From the immemorial time wood is highly abundant and well-performing material. Further one due to practical use the wood heat treatment, as a process for improving its properties has been enhanced in the recent tim. Abies alba Mill and Acer campestre L. are among the most wide spread species in Albanian forest and among the most useful types of wood in Albanian wood industry. The objective of this study is to investigate the influence of short time heat treatment on dimensional stability and the mass loss of these two species. Wood samples are treated in three different temperatures (180 ℃, 200 ℃, 220 ℃) and two different time durations of 15 and 30 minutes. After the heat treatment, the mass loss is determined for treated samples. Treated and untreated samples are immersed in water and the swelling is determined. According to the results obtained, wood swelling undergoes a considerable reduction in the case of wood treatment at a temperature of 220 ℃ for the longest time duration of 30 minutes. The higher percentage of weight loss after the thermal treatment (9.66% for the maple and 10.77% for the fir) was measured in the samples treated in a 220 ℃ for 30 minutes. The results of both treated and untreated wood were given for comparative purposes.

scholarly journals COLOR CHANGE — MASS LOSS CORRELATION FOR HEAT-TREATED WOOD

2014 ◽  
Vol 2 ◽  
pp. 345-352 ◽  
Author(s):  
Cristina Marinela Olarescu ◽  
Mihaela Campean
Keyword(s):  
Heat Treatment ◽  
Mass Loss ◽  
Color Change ◽  
Treated Wood ◽  
Untreated Wood ◽  
Cost Effective ◽  
Assessment Procedure ◽  
Mathematical Correlation ◽  
Heat Treated ◽  
Two Parameters

Heat treatment is renowned as the most environmentally friendly process of dimensional stabilization that can be applied to wood, in order to make it suitable for outdoor uses. It also darkens wood color and improves wood durability. The intensity of heat treatment can be appreciated by means of two parameters: the color change occured in wood due to the high temperature, and the mass loss, which is a measure of the degree of thermal degradation. In order to find a mathematical correlation between these two parameters, an experimental study was conducted with four European wood species, which were heat-treated at 180°C and 200ºC, for 1-3 hours, under atmosheric pressure.The paper presents the results concerning the color changes and mass losses recorded for the heat-treated wood samples compared to untreated wood.  For all four species, the dependency between the color change and the mass loss was found to be best described by a logarithmic regression equation with R2 of 0.93 to 0.99 for the soft species (spruce, pine and lime), and R2 of 0.77 for beech. The results of this study envisage to simplify the assessment procedure of the heat treatment efficiency, by only measuring the color – a feature that is both convenient and cost-effective. 

Synthesis and Characterization of Multi-Angular Branched ZnO Microstructures and Peculiar Nanopushpins Obtained by Thermal Treatment from Compacted ZnS Powder

2019 ◽  
Vol 286 ◽  
pp. 23-30
Author(s):  
J.R. Mora ◽  
Gregorio Flores-Carrasco ◽  
Mauricio Pacio ◽  
T.G. Díaz-Rodríguez ◽  
Hector Juárez
Keyword(s):  
Thermal Treatment ◽  
Treatment Process ◽  
Treatment Temperature ◽  
Complex Structures ◽  
Wurtzite Phase ◽  
Free Process ◽  
Different Temperatures ◽  
Short Time ◽  
Hexagonal Wurtzite Phase

Multi-angular branched ZnO microstructures with rods-shaped tips and nanopushpins with hexagonal cap on top have been synthesized by a simple thermal treatment process of compacted ZnS powder used as starting material and substrate. The structures have been grown at different temperatures (800, 900 and 1000 °C) for 60 min, in a constant nitrogen environment at atmospheric pressure via a catalyst-free process. XRD results of the as-grown products from ZnS powder show a significant reduction in the cubic zincblende phase to the hexagonal wurtzite phase with the increase of treatment temperature, as compared to the bulk value. Post-anneal analyses indicated that the transformation of morphologies of the as-grown structures also depends strongly on the treatment temperature. The proposed method represents an easy and economical way to grow complex structures of ZnO, with a relatively short time, furthermore, without the neediness of use an external substrate to grow. These new and interesting nanostructures have potential in applications such as optoelectronics.

scholarly journals Aging Behaviour Of AA6061/SiCP Composites Produced By Direct Extrusion With A Reversibly Rotating Die Method

2015 ◽  
Vol 60 (3) ◽  
pp. 1755-1762 ◽  
Author(s):  
J. Wozniak ◽  
M. Kostecki ◽  
K. Broniszewski ◽  
W. Bochniak ◽  
A. Olszyna
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Powder Metallurgy ◽  
Thermal Treatment ◽  
Solution Treatment ◽  
Complete Dissolution ◽  
Optimum Parameters ◽  
Different Temperatures ◽  
Higher Temperature ◽  
Unconventional Method

Abstract This paper discusses the influence of thermal treatment parameters on mechanical properties of AA6061+x% vol. SiCp (x = 0, 2.5, 5, 7.5, 10) composites. The composites were consolidated via powder metallurgy processing using the unconventional method of extrusion (the KoBo method). In order to establish the optimum parameters of the heat treatment two different temperatures of supersaturation (530 and 558ºC) were applied. The aging curves were determined at various aging temperatures such as 140, 160, 180 and 200ºC. The effects of applied parameters were studied using the microstructure observations and hardness measurements. Obtained results show that the solution treatment at 530ºC is sufficient to complete dissolution of the precipitates. Higher temperature of the process resulted in accelerating the aged-hardening. The suitable age treating parameters for the AA6061-5 vol. % SiCp composites were 160 - 180ºC for 12 - 16 hours.

scholarly journals Impact of heat treatment on the quality of tree-of-heaven wood

2019 ◽  
Vol 70 (4) ◽  
pp. 351-358
Author(s):  
Ioannis Barboutis ◽  
Vasiliki Kamperidou
Keyword(s):  
Heat Treatment ◽  
Thermal Treatment ◽  
Bending Strength ◽  
Untreated Wood ◽  
Climatic Conditions ◽  
Treatment Temperature ◽  
Modulus Of Rupture ◽  
Tree Of Heaven ◽  
Structural Applications ◽  
Hygroscopic Nature

Ailanthus altissima (Miller) Swingle is a deciduous, fast-growing species that can tolerate extreme climatic conditions and is particularly invasive. In the framework of climate change, and the imperative need for carbon greenhouse gases sequestration, this species could acquire increasing importance through its utilization in the construction of wood based products and structures, due to its satisfying properties combined with its fast growth. This study determines for the first time the influence of thermal treatment, under different conditions (190 ºC, 210 ºC, 230 ºC for 2 hours), on some crucial physical, hygroscopic and mechanical properties of wood, in an attempt to improve its intense hygroscopic nature and not so desirable colour. Thermal treatment affected the dimensional stability and water absorbing capacity of wood in a positive way, decreasing EMC, swelling (tangential–radial) and adsorption percent, compared to untreated wood. The anisotropy of wood was decreased only to a small extent. The total surface colour differences (ΔΕ*), prior and after treatment, ranged between 0.48 and 54.57, and appeared to be well correlated with treatment temperature. Only the most intensive treatment influenced negatively the modulus of rupture and impact bending strength of wood, while the elasticity and compression strength of treated wood were proved to be similar to those of untreated wood. Tree-of-heaven could benefit from a mild or medium intensity heat treatment process, in order to be modified to an aesthetically pleasing wood with enhanced hygroscopic nature and properties, facilitating its use in cabinetry and in variable indoor and outdoor non-structural applications.

scholarly journals INFLUENCE OF COMMERCIAL THERMAL TREATMENT ON Eucalyptus grandis Hill ex Maiden WOOD PROPERTIES

2021 ◽  
Vol 45 ◽  
Author(s):  
Carolina Aparecida Barros Oliveira ◽  
Karina Aparecida de Oliveira ◽  
Julio Cesar Molina ◽  
Vinicius Borges de Moura Aquino ◽  
André Luis Christoforo
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Thermal Treatment ◽  
Eucalyptus Grandis ◽  
Treated Wood ◽  
Wood Properties ◽  
Treatment Temperature ◽  
Saturated Steam ◽  
Physical Chemical ◽  
Different Temperatures

ABSTRACT This study aimed to evaluate the influence of commercial thermal treatment on Eucalyptus grandis considering its physical, chemical, and mechanical properties. The wood samples were heat-treated in an autoclave with saturated steam and pressure application at four different temperatures: 155, 165, 175, and 185 ºC. The physical, chemical, and mechanical properties were altered due to the heat treatment. The extractives content varied between 6.06% and 28.75%; lignin between 28.93% and 37.96%; holocellulose between 65.01% and 38.12%. The mechanical properties reduced significantly with the increase of the heat treatment temperature. Through the set of data obtained, it was possible to generate significant and high precision regression models capable of estimating such properties for heat treatment temperatures not studied experimentally, enabling the determination of the most suitable temperature of heat treatment to achieve a certain property value of the treated wood.

Microstructural Analysis of Zinc Niobate Ceramics Processed by Microwave Thermal Treatment

2020 ◽  
Vol 1012 ◽  
pp. 185-189
Author(s):  
Sergio Luiz Mineiro ◽  
Débora Aparecida Cunha Gonçalo ◽  
Sayuri Okamoto ◽  
Plínio Ivo Gama Tenório
Keyword(s):  
Heat Treatment ◽  
Thermal Treatment ◽  
Grain Growth ◽  
Crystalline Structure ◽  
Sintering Temperature ◽  
Microstructural Analysis ◽  
Processing Parameters ◽  
Microwave Oven ◽  
Final Microstructure ◽  
Different Temperatures

In this work are presented analyzes from calcination and sintering of zinc niobate ceramics by microwave processing. In order to obtain minimum processing parameters, the behavior of the material was first studied for the calcination at different temperatures in the range of 450 to 1150°C, with duration time of 10 minutes. The sintering was carried out between 950 and 1050°C. The results showed that the crystalline structure of the calcined and sintered samples was influenced by the temperature, because, according to the increase in temperature, the evolution of the formed crystalline phases was observed and only the Zn3Nb2O8 and ZnNb2O6 phases prevailed in the final microstructure. The densification of the sintered ceramics was influenced by the time and temperature of the heat treatment, with lower residual porosity and grain growth with the increase of the sintering temperature in the microwave oven.

Microstructure of Eucalyptus pellita under Different Thermal Treatment Temperatures and its Effect on Physical-Mechanical Characteristic

2011 ◽  
Vol 214 ◽  
pp. 544-548 ◽  
Author(s):  
Xue Hua Wang ◽  
Jun Liang Liu ◽  
Guo Qi Xu ◽  
Yu Bo Chai
Keyword(s):  
Heat Treatment ◽  
Thermal Treatment ◽  
Mechanical Characteristic ◽  
Bending Strength ◽  
Transverse Section ◽  
Microstructure Change ◽  
Eucalyptus Pellita ◽  
Pit Membrane ◽  
Different Temperatures ◽  
Cell Cavity

Taken the eucalyptus pellita treated for example, this article introduced the microstructure of wood without heat-treatment and microstructure-change under different temperatures (80°C, 120°C, 160°C, 200°C, 240°C, 280°C), analyzed the affect of the thermal treatment on wood’s physical-mechanical characteristic from microstructure. The result shows that: 1) pit membrane on the vessel tended to be broken or deciduous; 2) as the temperature ascending, fiber appears wizened and some grows rose, cell cavity trails off, severing of fiber could be saw on the transverse section, and brittle fracture on the radial cut; 3) weight reduced as temperature went up, while bending strength and modulus of elasticity descending after ascending, vertex appears when the temperature was 120°C, resistance was seriously lost at 280°C.

Untersuchungen zum Einfluss der Wärmebehandlung auf die Beständigkeit von Fichtenholz gegenüber holzzerstörenden Pilzen | Examination of the influence of heat treatment on the resistance of spruce timber to wood decaying fungi

2004 ◽  
Vol 155 (12) ◽  
pp. 548-554 ◽  
Author(s):  
Fritz Bächle ◽  
Peter Niemz ◽  
Markus Heeb
Keyword(s):  
Heat Treatment ◽  
Mass Loss ◽  
Ph Value ◽  
Treated Wood ◽  
Untreated Wood ◽  
Brown Rot ◽  
Nitrogen Atmosphere ◽  
White Rot ◽  
Heat Treated ◽  
Blue Stain

Spruce wood that was heat treated in rape oil (laboratory scale) and in an autoclave with a nitrogen atmosphere (industrial scale), respectively, was tested according to EN 113 for its resistance to basidiomycetes (4 brown and 1 white rot). In addition,resistance to blue-stain fungi was tested according to EN 152 and pH-values were measured in an outdoor ageing process. Influenced by the thermal treatment a clear decrease of mass loss induced by brown rot can be seen. There is an obvious influence of the kind of fungi and the level of treatment. Inoculated with Trametes versicolor (simultaneous white rot) a higher mass loss can be seen in the heat-treated specimens than in the untreated specimens. The big differences in the results between the fungi show that the type of fungi plays a role in the degree of influence. It would therefore seem that tests using only one fungus are insufficient. Similar results were achieved by testing previously weathered samples. The tendencies are not always similar. Blue-stain was occasionally detected near the surface of heat-treated wood. The pH-value of wood treated in an autoclave is clearly lower than that of untreated wood. The colour of the heat-treated wood is not UV stable. However, the colour achieved by the oil-heat-treatment is more stable than that achieved by a treatment in an autoclave.

Effect of a Complex Heat Treatment on the Structure of 300M Steel

1981 ◽  
Vol 39 ◽  
pp. 312-313
Author(s):  
R. Padmanabhan ◽  
W. E. Wood
Keyword(s):  
Heat Treatment ◽  
Metal Carbides ◽  
Austenite Grain Size ◽  
300M Steel ◽  
Heat Treated ◽  
Strain Fracture ◽  
Prior Austenite Grain Size ◽  
Short Time ◽  
Final Tempering ◽  
Similar Yield

Intermediate high temperature tempering prior to subsequent reaustenitization has been shown to double the plane strain fracture toughness as compared to conventionally heat treated UHSLA steels, at similar yield strength levels. The precipitation (during tempering) of metal carbides and their subsequent partial redissolution and refinement (during reaustenitization), in addition to the reduction in the prior austenite grain size during the cycling operation have all been suggested to contribute to the observed improvement in the mechanical properties. In this investigation, 300M steel was initially austenitized at 1143°K and then subjected to intermediate tempering at 923°K for 1 hr. before reaustenitizing at 1123°K for a short time and final tempering at 583°K. The changes in the microstructure responsible for the improvement in the properties have been studied and compared with conventionally heat treated steel. Fig. 1 shows interlath films of retained austenite produced during conventionally heat treatment.

Heat Treatment Influence on the Corrosion Resistance of a Cu-Al-Fe-Mn Bronze

2018 ◽  
Vol 69 (5) ◽  
pp. 1055-1059 ◽  
Author(s):  
Mariana Ciurdas ◽  
Ioana Arina Gherghescu ◽  
Sorin Ciuca ◽  
Alina Daniela Necsulescu ◽  
Cosmin Cotrut ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
Structural Changes ◽  
Heating Temperature ◽  
Galvanic Corrosion ◽  
Cooling Water ◽  
Open Circuit ◽  
Water Quenching ◽  
Heat Treated ◽  
Different Temperatures

Aluminium bronzes are exhibiting good corrosion resistance in saline environments combined with high mechanical properties. Their corrosion resistance is obviously confered by the alloy chemical composition, but it can also be improved by heat treatment structural changes. In the present paper, five Cu-Al-Fe-Mn bronze samples were subjected to annealing heat treatments with furnace cooling, water quenching and water quenching followed by tempering at three different temperatures: 200, 400 and 550�C. The heating temperature on annealing and quenching was 900�C. The structure of the heat treated samples was studied by optical and scanning electron microscopy. Subsequently, the five samples were submitted to corrosion tests. The best resistance to galvanic corrosion was showed by the quenched sample, but it can be said that all samples are characterized by close values of open-circuit potentials and corrosion potentials. Concerning the susceptibility to other types of corrosion (selective leaching, pitting, crevice corrosion), the best corrosion resistant structure consists of a solid solution, g2 and k compounds, corresponding to the quenched and 550�C tempered sample.

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