scholarly journals Selected Physical and Mechanical Properties of Microwave Heat Treated Rubberwood (Hevea brasiliensis)

2020 ◽  
Vol 10 (18) ◽  
pp. 6273
Author(s):  
Aujchariya Chotikhun ◽  
Jitralada Kittijaruwattana ◽  
Emilia-Adela Salca ◽  
Salim Hiziroglu
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Electron Microscope ◽  
Dimensional Stability ◽  
Hevea Brasiliensis ◽  
Physical And Mechanical Properties ◽  
Modulus Of Rupture ◽  
Heat Treated ◽  
Temperature Levels ◽  
Microwave Heat

The objectives of this study were to evaluate some of physical and mechanical properties of rubberwood (Hevea brasiliensis) as function of microwave heat treatment process. The specimens were heat treated at three temperature levels of 150 °C, 180 °C, and 220 °C for 20 min in a small microwave oven connected to a computer. Bending characteristics, namely modulus of elasticity (MOE), modulus of rupture (MOR) as well as hardness of the samples were tested. Dimensional stability in the form of swelling and water absorption of the specimens were also determined. Based on the findings in this work it appears that microwave can be used successfully for heat treatment of rubberwood. Overall mechanical properties of the samples were adversely influenced by the treatment. MOE, MOR and hardness values of the samples treated at a temperature of 220 °C had 2.37, 3.69, and 2.12 times reduced than those of control samples, respectively. Dimensional stability of the heat treated samples as a result of 2-h and 24-h water soaking improved. Micrographs take from scanning electron microscope (SEM) and transmission electron microscope (TEM) revealed that certain amount of damage took place in the cellwall of the treated specimens. Overall discoloration on the samples due to microwave heat treatment was found insignificant.

Physical and Mechanical Properties of Five Heat-Treated Hardwood Species

2012 ◽  
Vol 472-475 ◽  
pp. 1132-1134
Author(s):  
Jin Sun ◽  
Xiao Bo Wang ◽  
Xiao Jing Wang ◽  
Yan Lin ◽  
Zhen Zhong Gao
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Dimensional Stability ◽  
Negative Impact ◽  
Physical And Mechanical Properties ◽  
Betula Platyphylla ◽  
Fraxinus Mandshurica ◽  
Hardwood Species ◽  
Heat Treated ◽  
Betula Platyphylla Suk

Five hardwood species (Schima superba Gardn, kapur( Dryobalanops sp.), ash (Fraxinus mandshurica Rupr.), birch(Betula platyphylla Suk.), tauari (Couratari sp.)) were conducted the Heat treatment at 185°C.. The results indicated that the dimensional stability, modulus of elasticity (MOE) increased greatly while the wettability decreased after treatment. There was a negative impact of heat treatment on MORs.

Effect of Heat Treatment Combined with High Pressure Torsion Process on Microstructure and Hardness of AlMg5Si2Mn Alloy

2018 ◽  
Vol 275 ◽  
pp. 89-99
Author(s):  
Przemysław Snopiński ◽  
Tomasz Tański
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
High Pressure ◽  
Electron Microscope ◽  
Aluminium Alloy ◽  
Potential Application ◽  
High Pressure Torsion ◽  
Die Casting ◽  
Casting Alloy ◽  
Heat Treated

This study evaluated the effect of a heat treatment on the potential application of AlMg5Si2Mn die casting alloy as a substitute for wrought aluminium alloy products. The proposed heat treatment was intended to increase the workability of the AlMg5Si2Mn alloy, which is typically not malleable due to the presence of interconnected brittle phases. By disintegrating interconnected eutectic Mg2Si phases into fragmented particles and dissolving Mg-rich phases the workability was increased. Subsequently, heat treated samples were subjected to high-pressure torsion process. The microstructure of the heat treated and deformed samples were characterized using light and electron microscope. Hardness measurements were used to investigate the influence the number of HPT revolutions on mechanical properties.

Bamboo hybrid laminate board (Gigantochloa apus) strip with falcata veneer (Paraserianthes falcataria) in selected fiber directions

BioResources ◽  
2020 ◽  
Vol 15 (4) ◽  
pp. 9228-9242
Author(s):  
Ihak Sumardi ◽  
Rudi Dungani ◽  
Ignasia Maria Sulastiningsih ◽  
Deaul Aulia
Keyword(s):  
Mechanical Properties ◽  
Dimensional Stability ◽  
Urea Formaldehyde ◽  
Physical And Mechanical Properties ◽  
Modulus Of Rupture ◽  
Core Material ◽  
Fiber Direction ◽  
Paraserianthes Falcataria ◽  
Low Dimensional ◽  
Hybrid Laminate

This study investigated the physical and mechanical properties of bamboo hybrid laminate boards (BHLB) in various fiber directions as a potential wood-replacement structural material. This study used dry bamboo (Gigantochloa apus) processed into thin strips with a thickness of 4 mm and falcata veneer (Paraserianthes falcataria). The BHLB were arranged based on different fiber directions (i.e., perpendicular and parallel) in cold pressing (30 min; 22.2 kgf/cm2) and hot pressing (6 min; 15 kg/cm2). The adhesive used was urea-formaldehyde (UF) resin (glue spread rate of 250 g/m2 and inter veneer 170 g/m2). Physical and mechanical properties were observed to validate the feasibility of preparing BHLB from bamboo strips and falcata veneers. The results showed that the arrangement of the fiber direction affects dimensional stability, MOE (modulus of elasticity), MOR (modulus of rupture), shear strength, and screw withdrawal strength. Falcata veneer as the board core material resulted in lower density, low dimensional stability, and higher water absorption. However, the mechanical properties were not much different and fulfilled the standard for structural use. This study concludes that bamboo can be used for making composite BHLB as an alternative to wood-based composites for structural use.

scholarly journals PROPRIEDADES TECNOLÓGICAS DA MADEIRA DE EUCALIPTO SUBMETIDA AO TRATAMENTO TÉRMICO

Nativa ◽  
2018 ◽  
Vol 6 (5) ◽  
pp. 537
Author(s):  
Claudio Gumane Francisco Juizo ◽  
Lineia Roberta Zen ◽  
Walderson Klitzke ◽  
Morgana Cristina França ◽  
Vitor Gonçalves Cremonez ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Lignin Content ◽  
Chemical Properties ◽  
Physical And Mechanical Properties ◽  
Heat Treatments ◽  
Modulus Of Rupture ◽  
Technological Properties ◽  
Limit Condition ◽  
Heat Treated ◽  
Eucalyptus Wood

Este trabalho teve o objetivo de avaliar as propriedades tecnológicas da madeira de Eucalyptus sp tratada termicamente. Foram utilizadas amostras de madeira previamente secas até 12% de umidade, as quais foram separadas em cinco tratamentos, sendo um testemunha e quatro condições de exposição sob elevadas temperaturas e tempo, utilizando um forno cerâmico. As amostras foram separadas para avaliação das propriedades químicas, físicas e mecânicas. Nos resultados obtidos, observou-se decréscimo do teor de extrativos totais e holoceluloses, enquanto o teor de lignina de Klason aumentou com a temperatura e tempo de exposição. Da mesma forma, os tratamentos térmicos causaram acréscimo da perda de massa e da efetiva repelência de água, com redução da massa específica aparente, taxa de absorção de água e higroscopicidade da madeira. Na resistência das peças verificou-se aumento do módulo de elasticidade (MOE) e diminuição do modulo de ruptura (MOR) com aplicação de tratamentos térmicos. Na compressão paralela verificou-se aumento do MOE e MOR nas peças tratadas, servindo de parâmetros para possibilidades de uso estrutural da madeira até ao estado limite último. A tensão de Dureza Janka decresceu com aplicação dos tratamentos térmicos limitando a utilização dos mesmos em projetos que requerem maior resistência na superfície.Palavras-chave: Temperatura, Propriedades químicas, Propriedades físicas, Propriedades mecânicas. TECHNOLOGICAL PROPERTIES OF THE EUCALYPTUS WOOD UNDER THE HEAT TREATMENT  ABSTRACT:This work aimed to evaluate the technological properties of the heat treated wood of Eucalyptus sp. Were used wood samples Pre-dried up to 12% of moisture, which were separated into five treatments, one control and four diferente exposure conditions under high temperatures and time using a ceramic kiln. The samples were separated for evaluation of chemical, physical and mechanical properties. In the obtained results there was a decrease in total extractive and holocelluloses contents, while the Klason lignin content increased with the temperature and exposure times. In the same way, the heat treatments caused an increase of the mass loss and the effective water repellency with reduction of the apparent specific gravity, rate of water absorption and hygroscopicity of the wood. In the resistance of the pieces, the modulus of elasticity (MOE) was increased and the modulus of rupture (MOR) was reduced under the heat treatments. In the Parallel compression was verified increasing of MOE and MOR of the heat treated samples, serving as parameters for possibilities of structural use of the wood up to the last limit condition. The Janka hardness tensile decreased with the application of heat treatments, limiting the use of the wood in projects that require higher surface resistance.Keywords: temperature, chemical properties, physical properties, mechanical properties.

scholarly journals Termite Resistance, Chemical and Mechanical Characterization of Paulownia tomentosa Wood before and after Heat Treatment

Forests ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 1114
Author(s):  
Bruno Esteves ◽  
Helena Ferreira ◽  
Hélder Viana ◽  
José Ferreira ◽  
Idalina Domingos ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
New Species ◽  
Thermal Degradation ◽  
Dimensional Stability ◽  
Treated Wood ◽  
Extractive Content ◽  
Paulownia Tomentosa ◽  
Termite Resistance ◽  
Heat Treated

The introduction of new species in forest management must be undertaken with a degree of care, to help prevent the spread of invasive species. However, new species with higher profitability are needed to increase forest products value and the resilience of rural populations. Paulownia tomentosa has an extremely fast growth. The objective and novelty of this work was to study the potential use of young Paulownia trees grown in Portugal by using heat treatment to improve its properties, thereby allowing higher value applications of the wood. The average chemical composition of untreated and heat-treated wood was determined. The extractive content was determined by successive Soxhlet extraction with dichloromethane (DCM), ethanol and water as solvents. The composition of lipophilic extracts was performed by injection in GC-MS with mass detection. Insoluble and soluble lignin, holocellulose and α-cellulose were also determined. Physical (density and water absorption and dimensional stability) and mechanical properties (bending strength and bending stiffness) and termite resistance was also determined. Results showed that extractive content increased in all solvents, lignin and α-cellulose also increased and hemicelluloses decreased. Compounds derived from the thermal degradation of lignin were found in heat-treated wood extractions. Dimensional stability improved but there was a decrease in mechanical properties. Resistance against termites was better for untreated wood than for heat-treated wood, possibly due to the thermal degradation of some toxic extractives.

Influence of cooling rate on the physical properties, chemical composition, and mechanical properties of heat-treated rubberwood

Holzforschung ◽  
2020 ◽  
Vol 74 (11) ◽  
pp. 1033-1042
Author(s):  
Chuanfu Chen ◽  
Dengyun Tu ◽  
Xiangyu Zhao ◽  
Qiaofang Zhou ◽  
Banyat Cherdchim ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Chemical Composition ◽  
Physical Properties ◽  
Cooling Rate ◽  
Modulus Of Rupture ◽  
Tangential Section ◽  
Rapid Cooling ◽  
Heat Treated ◽  
Screw Withdrawal

AbstractThis study aimed to reduce the loss of mechanical strength in heat-treated rubberwood by rapid cooling. Heat-treated rubberwood specimens were prepared by controlling their cooling rate during the cooling phase of the heat treatment. The effects of cooling rate on the physical properties, chemical composition, and mechanical properties of heat-treated rubberwood were evaluated. Results indicated that cooling rate significantly influenced mass loss (ML). ML in heat-treated rubberwood cooled at 6 °C min−1 decreased by 23% relative to that in heat-treated rubberwood subjected to natural cooling. Compared with the heat-treated rubberwood subjected to natural cooling, the heat-treated rubberwood that was cooled at 4.5 °C min−1 increased in modulus of rupture (MOR), surface hardness, and screw withdrawal strength (tangential section) by 26, 8, and 16%, respectively. The cool rates exerted less effects on the dimensional stability, surface color, modulus of elasticity (MOE), compressive strength parallel to grain (CS), and screw withdrawal strength (radial section) of the heat-treated rubberwood. The application of rapid cooling to wood heat treatment could efficiently shortened the heat treatment period, thus increasing productivity.

Influence of Heat Treatment on Impact, Hardness and Fatigue Strength of 6061 Aluminium Alloy

2015 ◽  
Vol 761 ◽  
pp. 484-488 ◽  
Author(s):  
Nurulhilmi Zaiedah Nasir ◽  
Mohd Ahadlin Mohd Daud ◽  
Omar Bapokutty ◽  
Abdul Talib Din ◽  
Mohd Zulkefli Selamat
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Aluminum Alloy ◽  
Fatigue Strength ◽  
Heat Treated ◽  
Before And After ◽  
Temperature Levels ◽  
Number Of Cycles ◽  
6061 Aluminium Alloy ◽  
Alloy 6061

This paper presents effects of heat treatment on toughness, hardness and fatigue strength of aluminum alloy 6061. The alloy specimens were heat treated in the furnace at different temperature levels and holding times; and then cooled in different media (water and oil). The mechanical properties such as hardness, impact and fatigue were examined using standard method. Result shows that mechanical properties of aluminum alloy can be improved by the heat treatment. It was found that through ageing processes at temperature 160 °C for one, three and five hours, decreased the hardness, while increased the toughness. The fatigue strength was decreased when the number of cycles increased. The fracture surfaces between specimens have a different appearance before and after heat treatment.

scholarly journals Cross-Linked Chitosan as an Eco-Friendly Binder for High-Performance Wood-Based Fiberboard

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Erzhuo Huang ◽  
Yanwei Cao ◽  
Xinpeng Duan ◽  
Yutao Yan ◽  
Zhe Wang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Dimensional Stability ◽  
High Performance ◽  
Physical And Mechanical Properties ◽  
High Strength ◽  
Modulus Of Rupture ◽  
Wood Fibers ◽  
Promising Candidate ◽  
Pressing Method ◽  
Optimum Modulus

High-performance wood-based fiberboards with high strength and dimensional stability were fabricated by hot-pressing method using 2,5-dimethoxy-2,5-dihydrofuran (DHF) cross-linked chitosan (CS) as an eco-friendly binder. The effects of cross-linked chitosan on the mechanical properties and dimensional stability of wood-based fiberboards were investigated. It is evident that cross-linked chitosan addition was effective in improving mechanical properties and dimensional stability of wood-based fiberboards. The prepared wood-based fiberboard bonded by DHF cross-linked CS displayed optimum modulus of rupture (MOR) of 42.1 MPa, modulus of elasticity (MOE) of 3986.0 MPa, internal bonding (IB) strength of 1.4 MPa, and thickness swelling (TS) value of 16.3%. The improvement of physical and mechanical properties of wood-based fiberboards could be attributed to the amide linkages and hydrogen bonds between wood fibers and cross-linked chitosan. The high-performance wood-based fiberboards fabricated in this study may be a promising candidate for eco-friendly wood-based composites.

scholarly journals Evaluation of heat treatment parameters’ effect on some physical and mechanical properties of poplar wood with multi-criteria decision making techniques

BioResources ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. 4693-4703
Author(s):  
Alperen Kaymakci ◽  
Bahadır Çağrı Bayram
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Decision Making ◽  
Compression Strength ◽  
Modulus Of Elasticity ◽  
Bending Strength ◽  
Physical And Mechanical Properties ◽  
Multi Criteria Decision Making ◽  
Poplar Wood ◽  
Heat Treated

Effects of the heat treatment parameters were evaluated relative to some physical and mechanical properties of poplar wood (Populus alba L.) with use of two of the prominent multi criteria decision-making (MCDM) techniques: Entropy and The Technique for Order Preference by Similarity to Ideal Solution (TOPSIS). To meet this objective, the test samples were heat-treated at 120, 150, 180, and 210 °C for 2 and 4 h in a laboratory-scale oven. With increasing temperature and duration, the shrinkage and swelling ratios of heat-treated samples were improved. However, the bending strength, modulus of elasticity, and compression strength generally decreased with increasing process temperature and duration. According to (MCDM) analyses, thermal modification definitely improved the physical properties of wood up to a point. Bending strength was found to be the most important determinant of heat treatment success. The other determinants were identified as swelling, compression strength, shrinkage, and modulus of elasticity, respectively. Also, the best results were obtained at 120 °C for 2 h. In general, heat treatment above 150 °C or 4 h is not recommended.

Effect of Heat Treatment Parameters on Mechanical Properties of Medium Carbon Steel

2020 ◽  
Vol 22 (4) ◽  
pp. 909-918 ◽  
Author(s):  
M. M. Blaoui ◽  
M. Zemri ◽  
A. Brahami
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Cooling Rate ◽  
Heating Rate ◽  
Physical And Mechanical Properties ◽  
Medium Carbon Steel ◽  
Holding Time ◽  
Austenitization Temperature ◽  
Heating And Cooling ◽  
Heat Treated

AbstractEngineering materials, mostly steel, are heat treated under controlled sequence of heating and cooling to alter their physical and mechanical properties to meet desired engineering applications. This paper presents a study of the influence of austenitization temperature, cooling rate, holding time and heating rate during the heat treatment on microstructure and mechanical properties (tensile strength, yield strength, elongation and hardness) of the C45 steel. Specimens undergoing different heat treatment lead to various mechanical properties which were determined using standard methods. Microstructural evolution was investigated by scanning electron microscopy (SEM). The results revealed that microstructure and hardenability of the C45 steel depends on cooling rate, austenitization temperature, holding time and heating rate.

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