Water resistance of heat-treated welded Iroko, ash, tulip, and ayous wood

BioResources ◽  
2020 ◽  
Vol 15 (4) ◽  
pp. 9584-9595
Author(s):  
Mustafa Zor
Keyword(s):  
Shear Strength ◽  
Water Resistance ◽  
Chemical Constituents ◽  
Water Immersion ◽  
Control Sample ◽  
Strength Loss ◽  
Control Group ◽  
Line Density ◽  
Heat Treated ◽  
Structural Applications

The friction welding method has been an effective criterion in determining the mechanical performance of wood joints in wood industry applications compared to traditional methods. Although it is used in structural applications, joints from linear vibration are quite sensitive to water. In this study, the water resistance of the heat-treated woods, iroko (Chlorophora excelsa), ash (Fraxinus excelsior L.), tulip wood (Liriodendron tulipifera) and ayous (Triplochiton scleroxylon), were investigated by friction linear welding. The weld line density profiles were examined. The resistance of heat-treated welded wood joints to water remarkably decreased compared to the control sample, depending on water immersion time. The highest shear strength loss was found in tulip wood (60% to 65%) and the lowest shear strength loss was found in ash wood (3%) for the heat-treated group and in Iroko wood (17%) for the control. The heat-treated samples increased in density with welding but had a slightly lower density than the control group. According to the TGA results, it was found that the thermal degradation of untreated welded woods was lower than that of heat-treated welded woods. This difference could be due to the chemical constituents of hardwood and tropical wood. X-ray computed tomography (CT-scanning) is feasible and usable for welding line density change.

scholarly journals Water Absorption Behavior and Impact Strength of PVC/Wood Flour Composites

2010 ◽  
Vol 4 (3) ◽  
pp. 225-229 ◽  
Author(s):  
Gisele Iulianelli ◽  
◽  
Maria Bruno Tavares ◽  
Leandro Luetkmeyer ◽  
◽  
...  
Keyword(s):  
Impact Strength ◽  
Water Absorption ◽  
Moisture Absorption ◽  
Wood Flour ◽  
Chemical Constituents ◽  
Water Immersion ◽  
Control Sample ◽  
Maximum Water ◽  
The Difference ◽  
Wood Content

PVC/wood flour composites were prepared by compression molding using sapwood and heartwood from Angelin Pedra as filler. The composites specimens were subjected to water immersion and impact tests. The results showed that the water absorption of all composites increased slightly with increasing immersion time and wood content. However, the values were considerably low compared with control sample, common solid woods and wood plastic composites reported in literature. PVC/sapwood composites showed slightly higher values for moisture absorption ability due to the difference in chemical constituents’ ratio. PVC compound and PVC/sapwood composite containing 10 phr of wood flour exhibited maximum water absorption in 63 days and it corresponded to 0.25 % and 0.58 % weight gain, respectively. In relation to impact test, the results indicated that impact property was affected by wood content and less by wood type. Composites containing 10 phr of wood content showed greater impact strength (decreased by around 60 %) than those prepared with 25 and 40 phr of wood flour content (decreased approximately by 75 %). In general the composites prepared with 10 phr of wood flour content exhibited a better performance in both parameters measured in this study.

BETHLEHEM RQ-100A

Alloy Digest ◽  
1972 ◽  
Vol 21 (3) ◽  
Keyword(s):  
Fracture Toughness ◽  
Corrosion Resistance ◽  
Shear Strength ◽  
High Strength ◽  
Heat Treating ◽  
Pressure Vessels ◽  
Bethlehem Steel Corporation ◽  
Temperature Performance ◽  
Heat Treated ◽  
Structural Applications

Abstract BETHLEHEM RQ-100A is a heat-treated alloy steel having 100,000 psi yield strength through 11/4-in. thickness, in combination with good toughness, abrasion resistance and weldability. It is engineered specifically for structural applications such as earth moving equipment,buildings, bridges, and pressure vessels where high strength is required. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and shear strength as well as fracture toughness and fatigue. It also includes information on low and high temperature performance, and corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: SA-272. Producer or source: Bethlehem Steel Corporation. See also Alloy Digest SA-221, January 1968.

Adolescents’ self-mutilation - Relationship with dependent behaviour

2003 ◽  
Vol 62 (4) ◽  
pp. 241-249 ◽  
Author(s):  
M. Bolognini ◽  
B. Plancherel ◽  
J. Laget ◽  
P. Stéphan ◽  
O. Halfon
Keyword(s):  
Suicide Attempts ◽  
Clinical Sample ◽  
Control Sample ◽  
Clinical Population ◽  
Control Group ◽  
Clinical Group ◽  
Self Mutilation ◽  
Self Harm ◽  
Partial Overlap ◽  
The Relationship

The aim of this study, which was carried out in the French-speacking part of Switzerland, was to examine the relationship between suicide attempts and self-mutilation by adolescents and young adults. The population, aged 14-25 years (N = 308), included a clinical sample of dependent subjects (drug abuse and eating disorders) compared to a control sample. On the basis of the Mini Neuropsychiatric Interview ( Sheehan et al., 1998 ), DSM-IV criteria were used for the inclusion of the clinical population. The results concerning the occurrence of suicide attempts as well as on self-mutilation confirm most of the hypotheses postulated: suicidal attempts and self-mutilation were more common in the clinical group compared to the control group, and there was a correlation between suicide attempts and self-mutilation. However, there was only a partial overlap, attesting that suicide and self-harm might correspond to two different types of behaviour.

UNS A96101

Alloy Digest ◽  
1988 ◽  
Vol 37 (3) ◽  
Keyword(s):  
Electrical Conductivity ◽  
Corrosion Resistance ◽  
Shear Strength ◽  
Physical Properties ◽  
High Strength ◽  
Heat Treating ◽  
High Electrical Conductivity ◽  
Treated Condition ◽  
Heat Treated ◽  
Heat Treated Condition

Abstract UNS NO. A96101 in the heat treated condition is used primarily for enclosed bus conductor where both high strength and high electrical conductivity are desirable. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and shear strength as well as fatigue. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Al-287. Producer or source: Various aluminum companies.

UNS A02080

Alloy Digest ◽  
1988 ◽  
Vol 37 (1) ◽  
Keyword(s):  
Fracture Toughness ◽  
Corrosion Resistance ◽  
Shear Strength ◽  
Physical Properties ◽  
Tensile Properties ◽  
Heat Treating ◽  
General Purpose ◽  
Sand Casting ◽  
Casting Alloy ◽  
Heat Treated

Abstract UNS No. A02080 is a heat-treatable casting alloy characterized by good castability, machinability and resistance to corrosion. It is produced by sand casting and is a general-purpose alloy recommended in both the as-cast and heat-treated conditions. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and compressive and shear strength as well as fracture toughness and fatigue. It also includes information on corrosion resistance as well as casting, heat treating, machining, and joining. Filing Code: Al-286. Producer or source: Various aluminum companies.

scholarly journals Waterborne Polyurea Coatings Filled with Sulfonated Graphene Improved Anti-Corrosion Performance

Coatings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 251
Author(s):  
Jijia Zhang ◽  
Jihu Wang ◽  
Shaoguo Wen ◽  
Siwei Li ◽  
Yabo Chen ◽  
...  
Keyword(s):  
Composite Coating ◽  
Water Resistance ◽  
Electrochemical Impedance ◽  
Water Immersion ◽  
Doping Content ◽  
Corrosion Performance ◽  
Water Contact ◽  
Sulfonated Graphene ◽  
Long Time ◽  
Scanning Electron

In this paper, an environmentally friendly waterborne polyurea (WPUA) emulsion and its corresponding coating were prepared, which was characterized by dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), and scanning electron microscopy (SEM). To improve the performance of the coating, we doped sulfonated graphene (SG) into WPUA to prepare composite coating (SG/WPUA). SG can be uniformly dispersed in WPUA emulsion and is stable for a long time (28 days) without delamination. The water resistance of the composite coating with 0.3 wt.% SG nanofiller was improved; the water contact angle (WCA) result was SG/WPUA (89°) > WPUA (48.5°), and water absorption result was SG/WPUA (2.90%) < WPUA (9.98%). After water immersion treatment, SEM observation revealed that the SG/WPUA film only generated enlarged microcracks (100 nm) instead of holes (150–400 nm, WPUA film). Polarization curves and electrochemical impedance spectroscopy (EIS) tests show that SG nanosheets with low doping content (0.3 wt.%) are more conducive to the corrosion resistance of WPUA coatings, and the model was established to explain the mechanism.

scholarly journals Chitosan-Based Adhesive: Optimization of Tensile Shear Strength in Dry and Wet Conditions

2021 ◽  
Vol 2 (1) ◽  
pp. 110-120
Author(s):  
Maisa Abdelmoula ◽  
Hajer Ben Hlima ◽  
Frédéric Michalet ◽  
Gérard Bourduche ◽  
Jean-Yves Chavant ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Shear Strength ◽  
Bond Strength ◽  
Water Resistance ◽  
Tensile Shear Strength ◽  
Tensile Shear ◽  
Spread Rate ◽  
Assembly Time ◽  
Deacetylation Degree ◽  
Dry And Wet Conditions

Commercial adhesives present a high bond strength and water resistance, but they are considered non-healthier products. Chitosan can be considered as an interesting biosourced and biodegradable alternative, despite its low water resistance. Here, its wood bonding implementation and its tensile shear strength in dry and wet conditions were investigated depending on its structural characteristics. Firstly, the spread rate, open assembly time, drying pressure, drying temperature, and drying time have been determined for two chitosans of European pine double lap specimens. An adhesive solution spread rate of 1000 g·m−2, an open assembly time of 10 min, and a pressure temperature of 55 °C for 105 min led to a bond strength of 2.82 MPa. Secondly, a comparison between a high molecular weight/low deacetylation degree chitosan and a lower molecular weight/higher deacetylation degree chitosan was conducted. Tests were conducted with beech simple lap specimens in accordance with the implementation conditions and the conditioning treatments in wet and dry environments required for thermoplastic wood adhesive standards used in non-structural applications (EN 204 and EN 205). The results clearly revealed the dependence of adhesive properties and water resistance on the structural features of chitosans (molecular weight and deacetylation degree), explaining the heterogeneity of results published notably in this field.

scholarly journals Water Resistance and Creep Behavior of Heat-Treated Moso Bamboo Determined by the Stepped Isostress Method

Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1264
Author(s):  
Teng-Chun Yang ◽  
Tung-Lin Wu ◽  
Chin-Hao Yeh
Keyword(s):  
Heat Treatment ◽  
Water Absorption ◽  
Creep Behavior ◽  
Heat Treatment Temperature ◽  
Water Resistance ◽  
Absorption Efficiency ◽  
Treatment Temperature ◽  
Moso Bamboo ◽  
Phyllostachys Pubescens ◽  
Heat Treated

The influence of heat treatment on the physico-mechanical properties, water resistance, and creep behavior of moso bamboo (Phyllostachys pubescens) was determined in this study. The results revealed that the density, moisture content, and flexural properties showed negative relationships with the heat treatment temperature, while an improvement in the dimensional stability (anti-swelling efficiency and anti-water absorption efficiency) of heat-treated samples was observed during water absorption tests. Additionally, the creep master curves of the untreated and heat-treated samples were successfully constructed using the stepped isostress method (SSM) at a series of elevated stresses. Furthermore, the SSM-predicted creep compliance curves fit well with the 90-day full-scale experimental data. When the heat treatment temperature increased to 180 °C, the degradation ratio of the creep resistance (rd) significantly increased over all periods. However, the rd of the tested bamboo decreased as the heat treatment temperature increased up to 220 °C.

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