Wood Materials Research Articles

Traditional and biodegradable plastics host distinct and potentially more hazardous microbes when compared to both natural materials and planktonic community

Microplastic particles are persistent micropollutants that provide a substrate for the growth of bacterial biofilms, posing a threat to the environment. This study explores the changes in commercially available food containers made of conventional (polypropylene PP, polyethylene terephthalate PET), innovative biodegradable (Mater-Bi) and natural (wood and cellulose) materials, when introduced in the surface waters of Lake Maggiore for 43 days. Spectral changes revealed by FT-IR spectroscopy in PET and Mater-Bi, and changes in thermal properties of all human-made material tested indicated a degradation process occurred during environmental exposure. Despite similar bacterial richness, biofilms on PET, PP, and Mater-Bi differed from natural material biofilms and the planktonic community. Human-made material communities showed a higher proportion of potential pathogens, with PET and PP also exhibiting increased abundances of antibiotic resistance genes. Overall, these findings stress the need for dedicated strategies to curb the spread of human-made polymers in freshwaters, including innovative materials that, due to their biodegradable properties, might be perceived less hazardous for the environment.

Distribution and location of damages in Swedish buildings

Different damages and defects in buildings create huge cost for owners and the society. Besides free water damages, current knowledge about damages in buildings in general focuses on costs and has a qualitative approach rather than based on real quantitative facts. This paper presents the location and distribution of 1105 different damages, failures, and functional defects in Swedish buildings based on real damage investigations. Besides moisture inventories, most of the damage investigations were initiated by perceived SBS (Sick Building Syndrome) or visible free water. Possible negative effects on the indoor environment caused by different types of microbial growth were the most common damage. Damages often become noticed and, at a later state, located in ordinary rooms or classrooms. Most of the damages were located in the exterior wall and generally in wooden materials. The number of reported damages in the form of emissions from flooring due to degradation of glue was low in the studied sample.

Sound Absorption Properties of the Patented Wood, Lightweight Stabilised Blockboard

Abstract It is well known that wood tends to shrink and swell as the relative humidity of the air changes. There have been, and still are, attempts to make dimensionally stable wood panels such as Dendrolight®. The physical-mechanical, operational, including acoustic, properties of this material have been significantly improved compared to traditional wood-based panels. However, the production of this material requires very specific processing equipment and a large energy investment. The developers of this material in Latvia invented and patented wood, Lightweight Stabilised Blockboard (LSB). In order for this material to be used in the production of various products, it is necessary to clarify its characteristic, technological, as well as operational properties. The study gathers information about the sound absorption properties of various natural and wood materials, characteristics, and the sound absorption of the studied material at different sound frequencies. The reviewed sources of information indicate that nowadays there are still problems in sound conduction and absorption and isolation issues are being addressed in building acoustics. The production of samples and the determination of sound absorption were carried out using a developed methodology developed in accordance with regulatory requirements. The data obtained in the practical study were compared with the relevant indicators of the Dendrolight® and wood-based panels used for building structures and to determine their compliance with the requirements set forth in the standards ISO 10534-2 and ISO 11654. Research data show that LSB corresponds to E sound absorption class in some of the investigated frequencies.

Instrumented microindentation – a versatile technique in the field of wood science and technology

Hardness is an important mechanical property of wood or other wood-based materials and it is also very important in the case of wood coatings. Different indentation methods for measurements of hardness and other mechanical properties have been utilised already for a long time. In the last 50 years the instrumented indentation was developed. Here, an indenter tests the surface of a specimen with a controlled load and movement, in order to assess its mechanical properties. Three ranges of instrumented indentation tests are distinguished. In the macro range, the force is higher than 2 N, in the micro range it is below 2 N and the depth of indentation must exceed 0.2 μm. When the indentation depth is lower than 0.2 μm, the indentation technique is called nanoindentation. There can be found thousands of scientific papers about applications of instrumented nanoindentation in research of a large variety of materials. Instrumented microindentation remained somehow in the shadow of nanoindentation, but yet, it is a highly versatile technique with potentials to study various (micro)mechanical properties. In this review, examples of possible applications of instrumented microindentation are presented, with a focus on investigations of wood, wood-based composites, surface coated wood and polymeric films. In the second part of this paper, as an illustration, investigations of a self-healing wood paint are shown. The cyclic method and a single-load indentation confirmed the different mechanical properties and good scratch resistance of the self-healing paint.

Protection of pre-treated wood and construction materials using intumescent coatings

Intumescent paints’ behaviour is investigated for protecting wood pre-treated with phosphate or a silicate-based flame retardant. Additionally, the ageing effects of intumescent paint under several conditions are investigated. The cone calorimeter is applied, measuring the reaction to heat responses and the char development. Pre-treatment showed an improved fire performance of samples with intumescent coatings. The effects depend on the moisture contents and the homogeneity of the pre-treatments. Also, the experiments showed differences in fire resistance depending on the ageing method. UV exposure ageing retained the heat-insulating properties, while samples immersed in acid suffered a drastic reduction of their fire resistance. The latter ageing test increased the char’s pore size resulting in a reduced expansion factor and reduced thermal insulation performance of the intumescent coating.

Alaban wood (Vitex pinnata) as a promising feedstock in the community-scale charcoal industry: A case study of KPHP Kendilo, Indonesia

Indonesian forest production management unit, also called KPHP, have initiated various programs to develop the prosperity of local societies around forest area, including their independence in the energy sector. Charcoal is an ancient green energy which is still traditionally produced by those people for daily usage. Currently, the demand of charcoal for many modern industries in the world has been growing, showing its high potential as future export commodities since Indonesia has a richness in the forest biomass resources for charcoal feedstock. Therefore, we conducted a suitability analysis of the community-scale charcoal production at KPHP Kendilo, one of the forest management units located in East Kalimantan province. Alaban wood (Vitex pinnata) is considered the most potential biomass in this area, indicating its high availability in nature for charcoal feedstok. It was converted by a drum kiln technique using ratio of fuel wood and raw material at 1 : 2 (dry matter) for approximately 4 hours. It showed that the plant having diameter of above 15 cm possessed the highest charcoal yield (6.83 ton/ha), with appropriate energy properties (7,001 kcal/kg). Finally, this study points out the promising of Alaban wood in KPHP Kendilo for charcoal production in the rural communities.

Weather protection at the construction site: work environment and conditions for moisture and mould growth on massive timber

During the last decade, the use of timber (especially massive timber) has increased worldwide, mainly driven by anticipated environmental benefits. However, there is debate on how to handle the susceptibility against microbial growth for wooden constructions, especially during the construction phase. Sometimes full weather protection is used to avoid exposing the wooden material to outdoor conditions, but oftentimes the structures are fully exposed to precipitation. In an earlier study, one construction site using a full weather protection was studied, and the results showed promising results on the improved hygrothermal conditions and reduced risk of mould growth. Moreover, the site contractor also indicated improved work environment and productivity, however, this was not included in that study. This present study aims to investigate the effects of using full weather protection during construction in seven different construction projects to follow-up and broaden the earlier single project study. The studied aspects include the hygrothermal conditions, potential of mould growth, and influence on the work environment.Temperature and relative humidity were measured and analysed. Samples of cross-laminated timber (CLT) were analysed using a microscope, and the results are compared to theoretical mould growth potential. This is measured both inside the weather protection and outside at the seven construction projects. Furthermore, a work environment questionnaire is distributed to workers at the sites to collect the perceived work environment using a full weather protection.The results of the study partly confirm the conclusions from the earlier study, i.e., reducing the risk of mould growth and causing a slightly warmer and dryer conditions than outside. In addition, the results indicate an improved work environment. The majority of the interviewees wishes a weather protection in their next project regarding the work environment.

Physical, mechanical, and anatomical properties of 12 jabon (Neolamarckia cadamba) provenances wood in Indonesia

Abstract. Anna N, Siregar IZ, Supriyanto, Sudrajat DJ, Karlinasari L. 2023. Physical, mechanical, and anatomical properties of 12 jabon (Neolamarckia cadamba) provenances wood in Indonesia. Biodiversitas 24: 5895-5904. Jabon is a raw wood material for paper industries and has a fast-growing ability. Comprehensive information on the fundamental qualities of wood from the 12 provenances of jabon (Neolamarckia cadamba (Roxb.) Bosser) is a critical aspect of understanding their superior properties. The age of the samples at the trial was 42 months old, and the number of trees tested was 12, representing one provenance. Wood samples for physical (disk samples), mechanical, and anatomical properties were sampled at a height and length of 1.3 m and 35 cm. The logs were divided into 5 cm and 30 cm for wood samples with anatomical and mechanical properties. The physical and mechanical properties were tested according to ASTM D 4442, ASTM D 2395, and ASTM D 143 standards. The physical (density, specific gravity, and moisture content), mechanical properties (MOE and MOR), and anatomical properties (fiber length and microfibril angle) were carried out on wood from 12 provenances. Physical and anatomical properties were tested, from the pith to the outer bark. The average green wood density was 0.94 gcm-3, while the highest was obtained in the Rimbo Panti, Nusakambangan, Kapuas Tengah, and Batu Hijau provenances. The average specific gravity value from the 12 provenances of jabon was 0.46 in Batu Licin and Batu Hijau provenances; the average moisture content on oven-dry weight was 105.13%; and the highest value was in the Kuala Kencana provenance. The average MOE and MOR values were 51,039.93 kgcm-² and 488.37 kgcm-², with a dry air moisture content of 13.62%. The highest MOE and MOR values were in the Batu Licin and Gowa provenance, with MFA testing varied at 11.54°. The fiber length from the pith to the outer bark tended to increase, with an average of 1183.28 ?m. Based on the value of physical, mechanical, and anatomical properties, 12 provenances of jabon can only be used as non-structural raw materials. The Batu Hijau provenances have the highest density and specific gravity. However, the highest fiber length was found in Gowa provenance.

Evaluation of Safer House Roof Frame Models Using Coconut Wood Material

The use of coconut wood is considered an environmentally friendly alternative because coconut wood comes from people's plantations without destroying forests. Another problem in the wooden house industry is knowing that the method of making roof frames is not yet a safe standard. The objectives of this research are: 1) Provide information about how to obtain conventional wood and coconut wood materials. 2) Explain how to select the quality and type of wood. 3) Explain that coconut wood can be used as a roof frame. 4) Explain the technical obstacles to roof trusses using coconut wood. 5) Explain the model for making a roof frame based on the basic requirements for a safer house. The method used in this research is descriptive qualitative through qualitative data analysis. The results of the roof frame model for the Woloan house do not meet the requirements for a house that is safer from earthquakes

Experimental Study on the Failure of Bamboo Laminated Hollow Section Beam-Column Joints using Glue-in-Rod Bracket

Building materials that emit pollutants, are non-renewable, and generate environmental waste require attention. Wood, a popular and natural material, is facing increasing scarcity, necessitating a substitute. Laminated bamboo emerges as the most akin and natural alternative to wood. Research into laminated bamboo encompasses diverse cross-sections, joint types, and field applications, demanding further investigation.This study aimed to ascertain failure types and damage patterns in laminated bamboo hollow section beam-column joints modified with glue-in rod-bracket connections, using petung bamboo (dendrocalamus asper). The research employed an experimental approach with descriptive analysis. Joint failures were evaluated based on moment-rotation relationships within prescribed rotational limits per standards, while joint damage was assessed through visual inspection of joint components.The study's dependent variables included thread rod diameters of 6 mm, 8 mm, 10 mm, and 4 6 embedded thread rods, while the independent variables were failure types and joint collapses. Results revealed serviceability failures in samples 8.6, 10.4, and 10.6. Joint damage across all test specimens primarily manifested as broken thread rods. The highest joint strength observed was 6.28 kNm in sample 10.6, with the lowest at 2.25 kNm in sample 6.4.Based on the findings, increasing thread rod diameters to achieve ductile joints resulted in longer rotations but did not meet the planned strength due to bracket-induced prying effects causing bolt head failure. Despite this, the collapse type aligned with the research plan. Addressing the bracket's fulcrum effect during field applications requires solutions, potentially involving enlarging the bracket's base and increasing the number of thread rod points. The tests did not damage the laminated bamboo components, emphasizing the need to consider laminated bamboo cross-sectional dimensions and thread rod fulcrum effects in subsequent tests to ensure uniform component performance.

Comparative Optimisation of the Cutting Parameters for Surface Quality and Energy Efficiency during the Machining Manufacturing of Teak, Saligna and Pine Wood Materials

Comparative Optimisation of the Cutting Parameters for Surface Quality and Energy Efficiency during the Machining Manufacturing of Teak, Saligna and Pine Wood Materials

Experimental investigation on the influence of microwave technology on the treatability and mechanical properties of Portuguese southern blue gum wood

Despite presenting global relevance and satisfactory mechanical properties for structural applications, the Portuguese eucalyptus, southern blue gum (Eucalyptus globulus Labill.), faces difficulties with impregnation with preservative products due to its limited permeability (treatability), which limits its utilization. Microwave (MW) treatment of wood offers a promising avenue for overcoming this issue, but it may impact the mechanical properties. It was identified that there remain research gaps regarding the impacts of MW treatment on eucalyptus. Hence, it was aimed to identify the optimum MW parameters for southern blue gum wood to enhance its impregnability without compromising the mechanical properties. This will contribute to meeting the growing demand for wood for construction. Small clear wood specimens containing heartwood were separated into three groups: two underwent MW treatment, and one did not (control). The samples were impregnated with a preservative product and after submitted to mechanical testing. The MW treatment significantly enhanced the retention of the preservative product, which is remarkable given the impossibility of impregnating eucalyptus heartwood using conventional pressure methods. Although there were slight decreases in the mechanical properties of the MW-treated specimens, they were statistically equivalent to the control group. New insights into the mechanical bending behavior of MW-treated samples also arose. The mechanical properties of MW-treated eucalyptus samples surpassed those of other globally used wood species. Thus, MW treatment presented itself as an effective process for increasing eucalyptus impregnability, and it has the potential to augment southern blue gum's use as a raw sawn and engineered structural wood material worldwide.

Analyzing Temperature Distribution Patterns on the Facing and Backside Surface: Investigating Combustion Performance of Flame-Retardant Particle Boards Using Aluminum Hypophosphite, Intumescent, and Magnesium Hydroxide Flame Retardants.

Particle boards are manufactured through a hot pressing process using wood materials (natural polymer materials) and adhesive, which find common usage in indoor decorative finishing materials. Flame-retardant particleboard, crucial for fire safety in such applications, undergoes performance analysis that includes assessing temperature distribution across its facing surface and temperature increase on the backside surface during facade combustion, yielding critical insights into fire scenario development. In this study, a compact flame spread apparatus is utilized to examine the flame retardancy and combustion behavior of particle boards, with a specific emphasis on the application of cost-effective flame retardants, encompassing aluminum hypophosphite (ALHP), an intumescent flame retardant (IFR) comprising ammonium polyphosphate (APP), melamine (MEL), and Dipentaerythritol (DPE), alongside magnesium hydroxide (MDH), and their associated combustion characteristics. The D300°C values, representing the vertical distance from the ignition point (IP) to P300°C (the temperature point at 300 °C farthest from IP), are measured using a compact temperature distribution measurement platform. For MDH/PB, APP + MEL + DPE/PB, and ALHP/PB samples, the respective D300°C values of 145.79 mm, 117.81 mm, and 118.57 mm indicate reductions of 11.11%, 28.17%, and 27.71%, compared to the untreated sample's value of 164.02 mm. The particle boards treated with ALHP, IFR, and MDH demonstrated distinct flame-retardant mechanisms. MDH/PB relied on the thermal decomposition of MDH to produce MgO and H2O for flame retardancy, while APP + MEL + DPE/PB achieved flame retardancy through a cross-linked structure with char expansion, polyphosphate, and pyrophosphate during combustion. On the other hand, ALHP/PB attained flame retardancy by reacting with wood materials and adhesives, forming a stable condensed P-N-C structure. This study serves as a performance reference for the production of cost-effective flame-resistant particleboards and offers a practical method for assessing its fire-resistant properties when used as a decorative finishing material on facades in real fire situations.

Pemanfaatan Kombinasi Kayu Kemiri Dan Bambu Petung Sebagai Produk Papan Laminasi

The use of wood as a building material is inevitable despite the diminishing availability of the raw material. Laminated board is a technological advancement that offers an option to combine wood and non-wood materials. Increasing the dimensions and reducing the use of raw materials is an advantage in making laminated boards. If this technology is applied, it will be able to increase the utilization of laminated boards so that they become economical and always follow manufacturing standards. In this study, petung bamboo and candlenut wood were combined into a laminated board with the aim of identifying the value of its physical and mechanical properties. This experimental method is designed through 4 treatments with 2 factors. Based on the test results, the density value of 0.50 gr/cm3, moisture content of 14.26%, thickness shrinkage of 2.60%, thickness development of 1.67%, flexural strength of 10445.71 kgf/cm2 and fracture strength of 249.08 kgf/cm² were obtained. Apart from the results of the flexural and fracture toughness tests, it has passed the JAS 234-2007 standard test. From the test findings, it can be classified as having entered strength class III and is suitable for use as a sheltered heavy construction material.

Earthquake wonders: High school investigation in mortise tenon structures

Frequent global earthquakes lead to catastrophic property damage and casualties due to building collapses. However, the 1976 Tangshan Earthquake showcased an exception: the Forbidden City, constructed with wooden materials and featuring mortise-tenon structures, remained unscathed among surrounding destruction. This study investigates the earthquake-resilient attributes of wooden mortise-tenon joints utilizing economical high school equipment. An innovative low-cost sensor system, featuring custom instrumented hammer, is developed and validated. Calibration of the hammer's impact force employs correlation with acceleration data from a standardized scale weight during impact. The system's reliability is tested by comparing resonance frequencies from Finite Element modal analysis and experimental data for a cantilever beam. Impact hammer tests assess frequency response and damping across buildings with various joint configurations. Mortise-tenon joints display augmented frictional damping due to internal displacement. Through simulated vibration acceleration responses, a crucial finding emerges---integration of mortise-tenon joints translates to an impressive 11.0% reduction in earthquake vibrations. This research underscores the potential of accessible high school devices in advancing seismic engineering insights.

Surface Modification of Fast-Growing Wood with a Titanium-Dioxide-Based Nanocoating to Improve Weathering Resistance

Acacia mangium requires the addition of a finishing material to increase its resistance to weathering. Herein, the effectiveness of a nanocoating containing titanium dioxide nanoparticles (TiO2-NPs) as a finishing material for mangium wood was investigated. The coating material formulations used were oil-based (V1) and water-based (V2) varnishes with TiO2-NP concentrations of 1% (CT1), 5% (CT5), and 10% (CT10) (w/v). The uncoated and coated samples were subjected to weathering periods of 0, 2, and 4 months. The results showed that the addition of TiO2 nanoparticles to the V1 and V2 varnishes resulted in more gradual colour changes after the weathering period. The surface of the mangium wood also became smoother after being coated. However, the surface roughness increased with the duration of the weathering period. The wettability (K-value) of the sample decreased after coating, indicating that the coated sample was more hydrophobic than the uncoated sample. The results of a photocatalyst test, which analysed the effectiveness of the coatings, showed that the best coating material formulas were V1-CT10 and V2-CT10, as they degraded 75.21% and 71.03% of methylene blue content, respectively. Fourier transform infrared analysis showed that mangium wood did not undergo rapid weathering after the nanocoating treatment, as indicated by an insignificant decrease in the peak absorption intensity of the main structural functional groups of wood.

Flexible wood-based triboelectric nanogenerator for versatile self-powered sensing

With the continuous advancement of internet of things, big data, and artificial intelligence technologies, self-powered functionalized applications have emerged as pivotal components in the realm of smart technology. Here, we present a flexible and environmentally sustainable wood-based triboelectric nanogenerator (W-TENG) that enables the self-powered functionalization of applications in the emerging smart field. By employing a straightforward yet effective approach utilizing natural balsa wood, the W-TENG exhibits remarkable flexibility, stability, and sensitivity. Notably, balsa wood possesses a lower weight, density, and crystallinity compared to other types of natural wood, resulting in thinner internal cell walls, larger individual cells and a more porous structure. These characteristics prove particularly advantageous for solvent modification. Given the prevalent use of wood materials in domestic construction, the energy-efficient W-TENG can be seamlessly integrated into various smart applications, including wireless switches, home flooring, and energy-saving lamps. Moreover, this integration offers several benefits such as cost-effectiveness, high durability, ease of processing, and environmental friendliness. This research not only expands the range of self-powered applications in the smart sector but also drives the development of eco-friendly W-TENG electronics.

Novel strategy toward color-tunable and glow-in-the-dark colorless smart natural wooden window

Smart windows that use photochromic colorless wooden materials are an intriguing and urgent area of research. Herein, we create afterglow transparent woods with UV-induced photochromic capability. Infiltrating a lignin-modified wood (LMW) with a solution of methyl acrylate (MA) and rare-earth strontium aluminum oxide (SrAl2O4: Eu2+, Dy3+; SAOED) yielded afterglow and photochromic translucent wood. Preparing photoluminescent transparent wood effectively requires dispersing SAOED phosphor nanoparticles (NPs) in pre-polymerized MA without clumping. CIE (Commission Internationale de ĺEclairage) Lab colorimetric studies indicated that this transparent timber substrate changed color from colorless in daylight to greenish when exposed to ultraviolet rays. Micrographs taken using a transmission electron microscope (TEM) were analyzed to learn more about the morphology of the synthesized SAOED NPs. Different characterization techniques were applied on the photochromic translucent wood samples, including scanning electron microscopy (SEM), energy-dispersive X-ray analyzer (EDX), hardness properties, wavelength-dispersive X-ray fluorescent spectroscopy (WD-XRF), and absorption and emission spectroscopy. Absorption maximum wavelength was detected at 365 nm. Both 436 nm and 517 nm were observed as emission wavelengths in the developed photoluminescence wood. The results displayed that the manufactured transparent wood introduced superior protection from UV radiation and superhydrophobic activity. UV light triggered a rapid and reversible photochromic reaction in the transparent luminous wood.

A quantitative analysis of leaf life span reveals the Mesozoic significant gymnosperm Xenoxylon as evergreen: First evidence from the Early Cretaceous Jehol Biota in northeastern China

The Early Cretaceous Jehol Biota in western Liaoning Province of China and adjacent regions, is one of the most spectacular Mesozoic terrestrial lagerstätten in East Asia. Diversified fossil wood has been reported for the last two decades for the Jehol Biota. However, little is known about the fossil wood from the Lower Cretaceous Jiufotang Formation in the Kazuo area of western Liaoning. Here, we report new fossil wood material from the Lower Cretaceous Jiufotang Formation in Kazuo County of western Liaoning Province, northeastern China with well-preserved xenoxylean radial tracheid pitting and window-like cross-field pitting. Due to a novel combination of radial tracheid pitting, cross-field pitting and ray height, a new species, Xenoxylon kazuoense Xie, Wang, Tian et D.Uhl sp. nov., is recognized here belonging to the gymnosperm. Based on the well-preserved tree growth rings, we first perform a quantitative analysis of leaf life span for the Mesozoic common gymnosperm Xenoxylon. The result shows the tree X. kazuoense sp. nov. was evergreen with a leaf retention time (LRT) of 3–15 years. The discovery of this new species leads to a further understanding of the biodiversity of fossil wood in the Early Cretaceous Jehol Biota and the leaf phenology of trees growing in this area during the Early Cretaceous.

Effect of process parameters on the mechanical behavior of additively manufactured and FSW joined PLA wood sheets

AbstractFriction stir welding (FSW), a solid‐state joining method, is an innovative technique widely employed in the welding of thermoplastics, with broad application areas such as the automotive and aerospace industries. Due to its inherent advantages, including ease of processing, biodegradability, and printability, polylactic acid (PLA) and its derivatives are notably the most commonly used polymers in 3D printing. The limited print area of 3D printers necessitates post‐production joining processes. In this study, the weldability of plates obtained using PLA Wood filament through the FSW is evaluated. For this purpose, different pin geometries (triangle, square, and screw), feed rates (20, 40, and 60 mm/min), and tool rotation speeds (1250, 1750, and 2250 rpm) are employed. Visual inspections are conducted to determine the effects of process parameters on weld quality and to identify defects in the weld region. Temperature values are measured to investigate the influence of heat generated during the FSW process. Furthermore, after determining the highest weld strengths achieved for each pin geometry, the weldability of PLA Wood material with PLA‐CF and PLA Plus materials is investigated using these parameters. The results indicate that the highest weld quality for joining PLA Wood plates is achieved using the square pin geometry, 20 mm/min feed rate, and 1750 rpm with an efficiency of 74.5%. When welding PLA Wood with PLA‐CF and PLA Plus, high weld strengths are obtained using the same process parameters (square pin, 20 mm/min, and 1750 rpm).Highlights Friction stir welding process of 3D printed PLA Wood material. Friction stir welding process of dissimilar materials pairs. Effect of welding parameters on weld strength and hardness. Identifying the fracture surface images occurring in parts after friction stir welding. Examination of temperature generation during friction stir welding.