Higher Bending Strength Values Research Articles

Pengaruh Variasi Arus terhadap Kekuatan Bending pada Pengelasan Plat A36 Menggunakan Las SMAW (Shielded Metal Arc Welding)

The use of A36 plate in the construction sector is closely related to connecting or welding between metals because it is useful in assembling a product to lighten human work. Examples of the use of A36 plate in the construction sector can be seen in trellis workshops, where this plate is often used as a support or support in making a balcony or canopy. However, sometimes workers do not understand how strong the plate is after being treated with welding, often they just guess at the durability of the plate, so this can cause various kinds of losses. Starting from damage to work objects to causing work accidents that result in loss of life. Therefore, this research examines the effect of variations in current strength on bending strength. This test was carried out on A36 plate material which was subjected to welding effects with varying currents of 80A, 100A, 120A and 140A. and a bending test was carried out using the ASTM E190-14 test standard, the results of this test were that at a current of 80A the bending strength value was 161.173 N/〖mm〗^2. Current 100A with a value of 229.851 N/〖mm〗^2. Current 120A with a value of 270.374 N/〖mm〗^2. And a current of 140A with a value of 374.839 N/〖mm〗^2. The test object with a current strength of 140A is the test object that has the highest bending strength value.

Analysis of the slurry and ceramic properties for investment casting obtained with domestic colloidal silica binders

The quality of cast parts produced by investment casting is largely determined by the quality of the ceramic molds. Currently, aircraft and engine building enterprises are switching to an environmentally friendly colloidal silica binders for the manufacture of ceramic molds. In this work, the dynamic and relative viscosity of slurries prepared using fused silica powder and colloidal silica binders of the VT13-02U (Vakuumteh LLC), Stavroform VS (Polymet LLC), UltraCast One + and UltraCast Prime (both Technopark LLC) manufacturers were determined. It is shown that the slurries prepared on the considered binders have similar viscosity values, and in their rheological properties they are close to Newtonian liquids. The values of dynamic and relative viscosity at a binder content of 400 mL per 1 kg of fused silica powder were ~732 mPa·s and ~380 s, respectively. With an increase in the binder content to 600 mL per 1 kg of fused silica powder, the dynamic and relative viscosity decreased to ~70 mPa·s and ~16 s, respectively. An equation was also found that relates the dynamic viscosity determined using a rotational viscometer and the relative viscosity determined using the VZ-4 viscosimeter. The mechanical properties were determined during three-point bending tests on ceramic samples obtained using slurries on the above-mentioned colloidal silica binders and fused silica stucco. Samples obtained on binders VT13-02U, Stavroform VS and UltraCast One+ showed very similar bending strength values, namely 3.5–4.3 MPa after drying and 5.8–6.1 MPa after firing. Due to the presence of a polymer addition in the binder, the ceramic samples obtained on the UltraCast Prime binder had higher values of bending strength after drying and after firing – 6.4 and 7.2 MPa, respectively. It was also shown that with an increase in the viscosity of the slurry and a decrease in the fraction of fused silica stucco, the strength of the samples increases. The lowest surface roughness was observed for samples obtained with UltraCast grade binders.

The Effect of Fiber Volume Fraction on the Bending Strength of Fiber-Reinforced Composites of Oil Palm Empty Fruit Bunches

In this modern era, the palm oil industry is growing, so the waste is also increasing. If the waste from the palm oil industry is not processed, it will pollute the environment. One way to process palm oil waste is to turn the empty palm fruit bunches (OPEFB) fibers into composite reinforcement. Various natural fibers can be applied to become composite reinforcement, so it is necessary to study the character of OPEFB fibers for composite reinforcement. This study will look at the effect of various volume fractions on the bending strength of the composite. The volume fraction consists of 20%, 30%, and 40% fiber. The composite is then tested for bending to determine the bending strength of the composite. The results of the tests showed that the highest bending strength value was the 30% volume fractional variation with 47.70 MPa. The 40% volume fraction variation has the lowest bending strength value of 29.53 MPa.

Role of microstructural factor in wear resistance and cutting performance of high-speed steel end mills

The present paper describes the wear of high-speed steel (HSS) end mills with special emphasis on the influence of microstructural features, primarily the spatial distribution of eutectic carbides, on wear resistance. Hence, the wear resistance and performance of three HSSs of the same chemical composition but manufactured in three different ways, i.e. gravity casting, vacuum casting and a conventional metallurgical route, were compared. It was shown that the character of eutectic carbide spatial distribution in the HSS plays a major role in its wear performance, and, at the same hardness, it is independent of bending strength and impact toughness. For the studied range of eutectic carbide spatial distributions, tool life could differ up to 65 %. At both cutting speeds, 26 m/min and 40 m/min, the lowest wear resistance was determined for the end mills manufactured from the wrought HSS with uniformly distributed single particles of the dispersed eutectic carbides, and hence significantly higher values of bending strength and impact toughness. In contrast, the end mills manufactured from the as-cast material with coarser eutectic carbide networks along the primary matrix grain boundaries, and therefore worse mechanical properties exhibited the best wear resistance to abrasive and oxidational wear.

Wet chemical deposition of BN, SiC and Si3N4 interphases on SiC fibers

Fiber coatings based on BN, BN/SiC and BN/Si3N4 were deposited on Hi Nicalon type S SiC fibers. The coating parameters were optimized using a design of experiments study. With optimized parameter sets, the coatings exhibited a high degree of coverage on the fibers and almost no fiber bridging could be observed. The coated fiber bundles are flexible and can be processed further by techniques such as filament winding. In comparison to a non-processed reference sample, the maximum tensile load of the fiber bundles with BN, BN/SiC and BN/Si3N4 coatings was reduced by only 5 %, 13 % and 10 %, respectively. The coated fiber bundles retained their tensile strength after thermal annealing up to 1650 °C in a nitrogen atmosphere for 0.5 h. SiCf/SiC samples with BN/SiC fiber coatings exhibited higher values of bending strength and strain-to-failure as a reference sample without fiber coating indicating the functionality of the fiber coatings.

Spark Plasma Sintering of Cobalt Powders in Conjunction with High Energy Mechanical Treatment and Nanomodification

Spark plasma sintering (SPS) investigations were carried out on three sets of Co specimens: untreated, high energy mechanically (HEMT) pre-treated, and nanomodified powders. The microstructure, density, and mechanical properties of sintered pellets were investigated as a function of various pre-treatments and sintering temperatures (700–1000 °C). Fine-grained sinters were obtained for pre-treated Co powders; nano-additives tended to inhibit grain growth by reinforcing particles at grain boundaries and limiting grain-boundary movement. High degree of compaction was also achieved with relative densities of sintered Co pellets ranging between 95.2% and 99.6%. A direct co-relation was observed between the mechanical properties and densities of sintered Co pellets. For a comparable sinter quality, sintering temperatures for pre-treated powders were lower by 100 °C as compared to untreated powders. Highest values of bending strength (1997 MPa), microhardness (305 MPa), and relative density (99.6%) were observed for nanomodified HEMT and SPS processed Co pellets, sintered at 700 °C.

Evaluation of mechanical properties of poly (methyl methacrylate) reinforced with glass fibers

Introduction. Acrylic resin is a basic material used in preparation of partial and complete dentures. One of the methods of improving mechanical properties of removable dentures is reinforcing acrylic resin with artificial fibers. Aim of the study. To compare mechanical properties of acrylic material reinforced with various types of glass fibers. Material and method. Heat-cured Estetic acrylic resin by Wiedent was used for denture bases. Glass mat, fiberglass fabric, long glass fibers and short glass fibers were used as reinforcing phase of the acrylic resin. In total, forty specimens were prepared, of which eight samples were controls. Research samples consisted of four groups of eight specimens each. Mechanical examinations in three-point bending test were conducted by means of the Zwick 1435 universal testing machine. Results. Specimens reinforced with short glass fibers achieved the highest values of maximum bending force (105.7 ± 8.9 N). It corresponded to the highest values of bending strength (126.8 ± 10.7 MPa). The lowest strength was found for specimens reinforced with glass mat (82.8 ± 11.8 MPa). The highest value of Young’s modulus was obtained for the samples reinforced with fiberglass fabric (3.7 ± 0.8 GPa). The highest values of deflection at maximum bending force were found for the samples reinforced with long glass fibers (4.0 ± 0.6 mm). Conclusions. The highest bending strength parameters were found for specimens reinforced with short and long glass fibers. Short glass fibers are better at improving mechanical properties of acrylic resin than long glass fibers.

Properties of Veneered Flat Pressed Wood Plastic Composites by One-Step Process Pressing

The aim of this study was to develop, manufacture and determine properties of veneer overlaid flat pressed wood plastic composite (WPC) panels from recycled low density polyethylene (rLDPE), wood particles and different kinds of veneer (rotary-cut birch veneer and sliced oak veneer) using various adhesives by one-step hot pressing. Food packaging polyethylene film (PE film) as recycled stretch wraps, recycled low density polyethylene (rLDPE) particles and phenol formaldehyde (PF) resin were applied as adhesive for the bonding of veneer to the surface of WPC. No modification additives were used for the manufacture of WPC. It was found that compared with non-veneered WPC, the panels sandwiched with natural veneers greatly improved their properties. The bending strength was improved in 1.9–2.6 and 7.9–10 times across and along veneer fibers respectively for both types of investigated veneer. The highest values of bending strength were observed in WPC panels veneered with rotary-cut birch veneer. However, the water resistance of veneered WPC panels was reduced in comparison with non-veneered. The WPC specimens veneered with both types of veneer using PE film had better mechanical properties and water resistance than those of the specimens made with other two types of adhesives. The veneering of WPC panels enables to significantly improve adhesion properties of these veneered surfaces for their further finishing. In addition, the veneering of WPC panels hides the surface defects and provides a uniform application of different paints, varnishes and films to the surface of such materials. Overlaying WPC panels with wood veneers improves their appearance and properties resulting in eco-friendly value-added products.

Structure, microstructure and mechanical features of ceramic products of clay and non-plastic clay mixtures from Tunisia

Five clay and non-plastic mineral mixtures (M1, M2, M3, M4 and M5) from Tunisia were investigated for their possible ceramic applications. X-ray diffraction (XRD), thermal analysis (DTA/TG), dilatometry, scanning electron microscopy (SEM) and physical-mechanical analyses were used to assess the phase evolution and microstructure of the mixtures sintered between 900 and 1150°C. The decrease of water absorption and the increase of the bending strength of the samples were due to the formation of both the anorthite and mullite phases and the glassy phase helping to fill the pores. M1 and M2 had the highest values of bending strength at 1150°C. According to the European Norm EN 14411, these mixtures are suggested for porcelainized and fully vitrified stoneware thanks to their low water absorption (0.09 and 0.2%, respectively). M3, M4 and M5 mixtures (with respective water absorption of 2.74, 1.68 and 1.74%) are suitable for the production of vitrified stoneware.

Influence of Densification on Bending Strength of Laminated Beech Wood

This paper reports the influence of densification and cyclic loading on the bending strength of laminated beech (Fagus sylvatica L.). There have been many studies dealing with the bending strength of solid or laminated wood; however, densification is much less explored with respect to its use in the production of laminated wood. Laminated beech wood was loaded using three different numbers of cycles (1000, 2000, and 3000 cycles). Bending strength values of the cyclically loaded laminated wood were compared with that of laminated wood that was not cyclically loaded. The laminated wood was formed by a combination of densified and non-densified veneers, as well as polyvinyl cholride (PVC) fabric. The results show that the laminated wood consisting of densified and non-densified veneers, eventually with PVC film included, reached higher values of bending strength in comparison with the traditional composition consisting of non-densified veneers. Densification had a strong impact on the bending strength. Laminated wood composed solely with densified veneers achieved by 17.4% higher bending strength compared to the reference. On the other hand, the number of cycles did not influence the bending strength to a meaningful extent.

Structure-property relationships in mechanically stimulated Sorghum bicolor stalks

AbstractMechanical properties of plants and underlying structure-property relationships are important for agricultural purposes as well as for biomimetic concepts. In this study, the effect of mechanical stimulation on morphology and bending properties of the stalk was investigated for Sorghum bicolor (Poaceae), a widely used drought-tolerant biomass grass. An experimental set-up allowing for defined growth and mechanical perturbation (flexing) during a defined growth period was designed. Mechanical properties of individual internodes of the stalk were determined by three-point bending tests. We found that the three investigated lines showed differences in their general bending strength in the non-stimulated condition. However, similar high range of bending strength values was measured for all plant lines after they underwent the mechanical stimulation procedure. The anatomy of internode cross-sections was examined to evaluate structure-property relationships. An increased thickness of the outer sclerenchymatous tissue was observed for internodes with higher bending strength values. Dried internodes fail under lower strains but showed higher bending strength. These findings show that mechanosensitivity in sorghum is dependent on genetic as well as environmental factors. The experimental system presented here offers new straight-forward possibilities for S. bicolor line selection for applications requiring mechanical strength of the stalk.

The effect of microstructural features on the mechanical properties of LZSA glass-ceramic matrix composites

This work reports on the characterization of ZrSiO4 particulate-reinforced Li2O-ZrO2-SiO2-Al2O3 (LZSA) glass-ceramic matrix composites. The typical physical/mechanical and chemical properties of the glass batches and the composites were measured. A composition with 60 wt.% ZrSiO4 was preliminarily selected because it demonstrated the highest values of bending strength (190 MPa) and deep abrasion resistance (51 mm³). To this same composition was given a 7 wt.% bentonite addition in order to obtain plasticity behavior suitable for extrusion. The sintered samples (1150 ºC for 10 min) presented a thermal linear shrinkage of 14% and bending strength values of 220 MPa.

Effect of Thermal Shock on Bending Strength of Composites Made from Fly Ash and Glass Waste

The bending strength of composite made from fly ash and glass waste can be improved by controlling chemical composition of the raw materials and sintering temperatures. In this study, the composites made from mixture of various weight fractions between fly ash (FA) and glass waste (GL). Each mixture was uni-axially pressed with various compacting pressures to produce green body. The formed green body was then sintered at various temperatures from 900 °C to 1100°C for 2h. From the experimental result, it shows that the bending strength of composite fly ash and glass waste is highly varied based on the weight fraction of glass waste content, sintering temperatures and compacting pressures. The highest bending strength value is 44.53 MPa obtained from specimen that contains 50 (% wt.) of glass waste with sintering temperature of 1050 °C and compacting pressure of 130 MPa. A thermal shock test was performed on the specimen composites of 50FA-50GL by heating up to various temperatures and followed by quenching (rapid cooling) to water media. Bending test was then done on the thermal shocked specimen. The bending strength of specimen decreases sharply around 80.93 % from its original strength when subjected to temperature gradient (ΔT) of 285 °C.

Mechanische Biegefestigkeiten von explantierten Ex-vivo-Knochenzementen verglichen mit In-vitro-Proben

The mechanical properties of acrylic bone cements are an important factor in determining an efficient load transmission between prosthesis and bone to guarantee the long-term stability in cemented hip arthroplasty. Palacos and Refobacin Palacos specimens from 21 aseptically loosened femoral compoments of cemented hip arthroplasties manufactured by the first to third generation cementing technique have been mechanically tested in a standardised four-point bending test (ISO 5833). In vitro manufactured Palacos and Refobacin Palacos specimens served as a control group. The fatigue fracture surfaces were morphologically analysed with light microscopy. Under in vitro conditions manufactured specimens had higher values of bending strength, with the exception of blood contaminated ones, compared to ex vivo specimens. Ex vivo specimens of the second and third generation cementing technique had higher values than specimens of the first generation. Acrylic bone cements are subjected to a multifactorial material fatigue in vivo. Here, the art and quality of cementing technique is of eminent importance in determining the long-term stability of cemented hip arthroplasty.

Mechanische In-vitro-Prüfung von fünfzehn kommerziellen Knochenzementen auf der Basis von Polymethylmethacrylat

INTRODUCTION The long-term stability in cemented hip arthroplasty depends not only on the mechanical properties of the acrylic bone cements but also on an improvement of cementing techniques. The bending strengths of 15 commonly used bone cements (CMW 3 Gentamycin; CMW 3; Refobacin Palacos R; Palacos R; Palamed G; Palamed; Cerafixgenta; Cerafix; Duracem; Simplex Tobramycin; Simplex P; Versabond; Sulcem; Sulcem 3 Genta; Copal) have been mechanically tested in a standardised in vitro four-point bending test (ISO 5833). The fatigue fracture surfaces were morphologically analysed with light microscopy. The highest values of bending strength were found in vacuum mixed specimens cured under pressure. The lowest values of strength were seen in with blood contaminated specimens. Fatigue cracks were often initiated from air bubbles or other inclusions such as antibiotics or blood in the bone cement. The present in vitro study highlights the supposition that the quality of the cementing technique is of eminent importance in determining the long-term stability of cemented hip arthroplasties.

Structural performance of the finger-jointed strength of some wood species with different joint configurations

This study was conducted to evaluate the effects of adhesive type, wood species, and finger joint configurations on structural performance of the finger joint. The wood species studied were oriental beech ( Fagus orientalis lipsky.), oak ( Quercus robur), Scots pine ( Pinus sylvestris lipsky.), poplar ( Populus tremula lipsk.) and Uludağ fir ( Abies bormülleriana Matff.) and adhesives were poly(vinyl acetate) (PVAc), Desmodur-VTKA (D-VTKA). However, there is little information available concerning the bending strength and modulus of elasticity for finger joints in these field. In this study, it was aimed to determine the bending strength and modulus of elasticity for finger joints. For this purpose, samples were tested according to the TS EN 310 standard. It was observed that the highest bending strength and modulus of elasticity were obtained in beech control (solid wood) samples. As for the finger joints, after the control samples, the highest bending strength value (57.4 N/mm 2) was obtained from Oriental beech wood samples having a 21 mm finger length and bonded with PVAc adhesive, the highest modulus of elasticity (8885.3 N/mm 2) was obtained from beech wood samples having a 21 mm finger length and bonded with PVAc adhesive. As a result of the effects of finger joints on bending strength and modulus elasticity test, if the length of finger joints increases up to 21 mm, the properties of bending strength increase.

Mechanical properties of alumina-rich magnesium aluminate spinel/tungsten composites

The mechanical properties and microstructure of alumina-rich magnesium aluminate spinel/tungsten (14 and 22 vol.% W) composites obtained by hot press at 1650 °C under reducing conditions have been investigated. The R-curve for these composites was estimated by the indentation strength method and compared with that of the monolithic spinel obtained under similar conditions. Rising R-curve behavior was specially observed in the composites when tungsten content was higher. Other mechanical properties such as hardness, toughness, Young's modulus and bending strength, were also determined for both (composites and monolithic magnesium aluminate). Higher values of bending strength were found as the metal volume fraction increases in the composite. The metal content dependence of Young's modulus and Vickers hardness follow the rule of mixtures. Mechanical properties and specially toughness are influenced by the metal content and its grain size.

Effects of polymer amount and processing conditions on the in vitro behaviour of hybrid titanium dioxide/polycaprolactone composites

Titanium dioxide (TiO 2) and TiO 2 glasses containing poly( ε-caprolactone) (PCL) up to 24% by weight were obtained by the sol–gel process. Powder compaction was achieved providing heat and pressure. Properties were evaluated through compression and bending tests assisted by X-ray micro-computed tomography imaging. The effects of compaction conditions (i.e. temperature, pressure and duration) on mechanical properties of inorganic/organic composites were investigated. Biocompatibility tests on organic/inorganic composites were carried out using human cells and the MTT assay to determine viability. Results indicated that the mechanical properties (i.e. Young's modulus and maximum strength), in both compression and bending, were a function of the compression moulding conditions. Highest mechanical properties were measured using a compaction pressure of 1500 MPa acting for 90 min at a die temperature of 100 °C. The results, however, also suggest that mechanical properties can be tailored by varying the amount of PCL to TiO 2. Strength and stiffness spanned between the properties of spongy and cortical bone. Young's modulus in both compression and bending were higher for PCL amounts of 6%. Instead, higher bending strength values were measured for PCL amounts of 12%. These weight amounts of PCL also provide higher average density values, thus suggesting that the polymeric phase is effective in toughening TiO 2-based materials. The investigated materials also showed a very good cytocompatibility as indicated by the MTT assay results.

Proton—conducting ceramics as electrode/electrolyte—materials for SOFCs: Preparation, mechanical and thermal-mechanical properties of thermal sprayed coatings, material combination and stacks

Abstract This part of investigation includes the synthesis, preparation and examination of the cathode lanthan–strontium–manganite (ULSM) as bulk material, the BCN electrolyte as coating and the cermet anode (BCN/Ni) as coating too. The ULSM powder was made by the conventional solid reaction of carbonates and oxide. The ULSM samples were cold pressed and sintered at temperatures between 1400 and 1600 °C. The measurement of the mechanical properties like bending strength (room and high temperature), Young modulus ( E ), modulus of rigidity ( G ), Poison's ratio, hardness and fracture toughness were done for the ULSM bulk material. The highest values of bending strength, E and G was found to be 85 MPa, 192 GPa and 46 GPa, respectively for the dense material and only 26 MPa bending strength for the porous material (30% pores). The hot bending strength (800 °C) was also in the range of 25 MPa for the porous material. In the case of BCN coatings cold bending strength was determined to 55 MPa for the dense material (99% TD). E - and G -moduli were in the range of 190 and 46 GPa in maximum while Poisons ratio was about 0.35. Vickers hardness was resulted in a maximum value of 5 GPa while Poison's ratio was about 0.35. Finally the cold bending strength of the porous cermet coatings (30% porosity) was measured to 54 MPa with an E -modulus of 15 GPa. The Vickers hardness was about 0.2 GPa and the coefficient of thermal expansion about 11×10 −6 K −1 . Finally, the material combination cathode/electrolyte (ULSM–BCN) and the stacks (ULSM–BCN–BCN/Ni) were prepared and examined. The ULSM samples were cold pressed and sintered at temperature of 1400 °C with a porosity of about 30%. On the surface of ULSM the BCN electrolyte was prepared by plasma spraying. On the surface of the electrolyte the BCN/Ni anode was prepared by flame spraying. The measurement of the mechanical properties like bending strength (room and high temperature), Young modulus ( E ), adhesion strength were done for the material combination and adhesion strength and thermal shock resistance was measured for the stacks too. The values of bending strength and E were found to 35 MPa and 62 GPa, respectively for the material combination. The hot bending strength (800 °C) was in the range of 59 MPa and an E of 51 GPa. The adhesion strength was determined to 0.24 MPa for the material combination and 0.42 MPa for the stacks and the thermal shock resistance of the stacks was greater than 20 cycles.

Effect of the Surface Structure of Si-Ti-C-O Fiber on the Properties of Three-Dimensional Fiber-Reinforced Silicon Carbide Composites

Three-dimensional Tyranno® fiber-reinforced silicon carbide composites were fabricated by using polycarbosilane as the precursor for matrix and some types of fiber with different surface structures. Composites made of a fiber with an excess carbon layer at the surface had the highest values of bending strength and fracture toughness at room temperature. Composites of a fiber with a double layer of oxide and carbon had the largest value of work of fracture and a superior oxidation resistance property.