Tensile Strength Of Specimens Research Articles

Effect of Annealing Temperature on Mechanical Behavior, Pitting Resistance and Grain Boundary Character of a 2304 Lean Duplex Stainless Steel

The effect of the annealing temperature on mechanical behavior, pitting resistance, and grain boundary character of 2304 lean duplex stainless steel was studied. For this purpose, 4 mm thick hot-rolled sheets were cold-rolled up to a thickness of 1 mm, followed by isochronal annealing from 900 °C to 1100 °C for 180 seconds. Microstructural and CSL boundary analysis were carried out by electron backscatter diffraction technique. The SIM formation was examined by transmission electron microscopy and the phase distribution was quantified by X-ray diffraction. Mechanical properties were evaluated based on microhardness measurements and tensile tests, and the electrochemical analyses were performed by potentiodynamic polarization studies. The results revealed a Nishiyama–Wasserman relationship between α′-martensite laths and the metastable austenite after cold rolling. Increasing temperature enhanced the softening and ductility but decreased yield and tensile strengths of specimens. The deformation-induced martensitic transformation took place less actively and the strain-hardening rate decreased at higher temperatures. The improvement in ductility was related to the increasing fraction of $$ \sum 3 $$ boundaries in the austenite, whereas the strength worsening was associated with the increasing fraction of the $$ \sum {13b} $$ boundaries in the ferrite as temperature increased. The nucleation of metastable pits changed from austenite to the ferrite phase and the pitting potential shifted to nobler values with increasing annealing temperature. The increasing pitting resistance of austenite was associated with the increase in the fraction of $$ \sum 3 $$ boundaries, while the decreasing pitting resistance of ferrite was related to the increased fraction of the $$ \sum {13b} $$ boundaries at higher annealing temperatures.

3D Printing of Ground Tire Rubber Composites

Recycled tire rubber is an environmentally and economically beneficial material. Ground tire rubber (GTR) as a filler in a polymer matrix was used as an ink material (composite material) for material extrusion in a 3D printing process. The maximum allowable amount of GTR incorporated into the mixture without significantly altering the rheological behavior of the ink was set. Printability investigations revealed that pressure and speed show linear and power relationships, respectively, to the line width for three different amounts of GTR. Moreover, the post-curing time of 30 min at 115 °C was set as the full-cure condition to achieve polymerization of 80% or more for the 3D printed parts. Unidirectional tensile testing demonstrated that 3D printed specimens exhibit no degradation in tensile strength when compared to molded specimens. Moreover, printability and mechanical properties of functionalized GTR were investigated to determine if this material exhibits enhanced mechanical strength. Unidirectional tensile tests show that the maximum tensile strength for specimens with functionalized GTR was 20% higher than in specimens with non-functionalized GTR. In conclusion, 3D printing of GTR composites shows promise for using recycled GTR to create 3D structures with rubber-like properties.

ANALISIS KEKUATAN DAN KUALITAS SAMBUNGAN LAS DENGAN VARIASI PENDINGINAN OLI DAN UDARA PADA MATERIAL ASTM A36 DENGAN PENGUJIAN NDT (NON DESTRUCTIVE TEST)

Welding is the process of joining two metals to the point of metal recrystallization using either added or not material and using heat energy as a melting agent. In this study, different cooling variations on each specimen were carried out, the material used was ASTM A36 Plate, 3.2 mm diameter E7018 electrode, cooling used with Oil and Air. in the implementation of welding using the SMAW (Shielded Metal Arc Welding) welding method. From the above understanding, research and testing are carried out including tensile tests, radiography / x-rays, and penetrants. The purpose of this study was to determine the strength and quality of welded joints that were not seen with the Destructive Test on the ASTM A36 plate and also to determine the effect of variations in oil and air cooling. From this study it can be found that the tensile strength values for specimen 1 (Oil ) is 373.06 MPa. While the value of tensile strength for specimen 2 (Air) is 365.31 MPa, this means that it has decreased by 7.75 MPa from the tensile strength of specimen 1 (Oil).

Tensile strength of GFRP and hybrid composites under various environmental conditions

Purpose The purpose of this paper is to study the mechanical behavior of glass fiber reinforced polymer (GFRP) and hybrid composites under various adverse environmental conditions. This mainly helps the researchers to overcome the obstacles that have been met when they use the materials individually and also to know the impacts of environment on them. Design/methodology/approach The GFRP and hybrid specimens are made according to the American Society for Testing and Materials standard. The specimens are then immersed in aviation turbine fuel, hydraulic fluid and concentrated sulfuric acid. The tensile strength of the specimens is then determined using the universal testing machine. Findings The tensile strengths of the normal specimens and the specimens subjected to various environmental conditions are determined. The results obtained for GFRP and hybrid specimens are then compared. Research limitations/implications The researchers can extend the time intervals further for a better understanding of the strength of the composites. Practical implications Once better combinations are found out with the highest strength to weight ratio and its resistance to various adverse environmental conditions, it can be used in real-time applications. Social implications The best hybrid combinations can be used in place of metals in future. Originality/value This is an original research and is clearly based on the experimental results, so it adds very much value to the aviation industry because strength to weight ratio is one of the major issues to be taken into consideration.

Investigation of Adhesive Joint Strength for Dissimilar Metal Adherends by Using Taguchi Method

The dissimilar metal joints of stainless and medium carbon steel have been emerged as a structural joint for various industrial applications which provides good combination of mechanical properties like strength, corrosion resistance with lower cost. This paper concerned with the growth of adhesive joint technique since adhesive joint has the applicability to joint wide variety of engineering materials. This study is to investigate the significance of factors in dissimilar AISI 304/1045 butt-joint specimen tensile strength by using Taguchi method and Analysis of Variance (ANOVA). The joining strength was evaluated with manufacturing factors of abrasive paper, heat treatment and adhesive thickness. It was obtained that abrasive paper has significant effect on adhesive joint strength while heat treatment effect is insignificant. Nevertheless, the joint strength decreased with increment of adhesive thickness.

Laser sintering process of ceramic powders: The effect of particle size on the mechanical properties of sintered layers

Selective Laser Sintering (SLS) of ceramic powders is studied in order to understand how the initial material properties and the process conditions affect the degree of sintering/melting and the mechanical properties of the sintered material. Unimodal powder samples of different narrow particle size distributions between 16 and 184 μm were sintered with a 40 W CO2 laser, using laser scan speeds of either 50 or 100 mm s−1 and, in both cases, a scanning energy of 160 J m−1. The sintered material was studied by means of optical and SEM microphotography and characterized in terms of bulk density and tensile strength. The Rumpf approach to relate interparticle forces to the strength of powder agglomerates was used in this work to estimate the average strength of the sintered interparticle contacts starting from the tensile strength of specimens. In turn, the average strength of the neck contact was used to estimate the size of the neck of fused material between two sintered particles. These data coupled with the Frenkel model for particle sintering allowed an estimate of the sintering temperature for the different experimental conditions tested. The temperatures found are consistent with the glass transition temperature of the material used. The effect of particle size and scanning speed is assessed and discussed.

Improvement of asymmetry in a friction stir welded A3003/SUS 304 lap joint by double-pass process

ABSTRACTDouble-pass process was newly performed to a friction stir welded (FSWed) A3003 aluminium alloy/SUS304 stainless steel dissimilar lap joint in order to improve the asymmetry of the FSWed joint. A sound symmetrical joint was produced by running the tool again at the bead which ˆrstly produced by FSW. Tensile strength of specimens was improved by leaving the tool distance from 2 mm to 5 mm where both edges of the stirred zone were advancing side (AS-AS joint). Micro-tensile test revealed that most of the stirred zone in the AS-AS joint with the tool distance of 5 mm fractured at A3003 base metal.

Differences Strength of Low Carbon Stainless Steel St 37 with Electrical Welding Compound V Use Materials Add Electrodeof Type-RB and Type -RD

This study aims to determine the difference in tensile strength of low carbon steel St 37 which is welded with RB type and RD type electrodes. The welding utilizes the type of a V-shaped joint with an angle of 600. After low carbon steel St 37 is then subjected to a tensile strength test / tensile test to obtain a tensile strength value. This research uses experimental method by preparing the object of research in the form of tensile test specimen which amounted to 19 pieces and separated into 3 groups. Group I was an untreated / non-welded St 37 carbon steel, a Group II of low carbon steel St 37 welded with RB type electrodes, and a Group III of low carbon steel St 37 welded with RD type electrodes. The cooling medium used after welding is air. The tensile test results show that the average tensile strength of low carbon steel St 37 without welding has a tensile strength of 48.02 kg/mm2 with the largest specimen tensile strength of 48.33 kg/mm2 and strength At the low carbon steel welding St 37 using RB type electrode has an average tensile strength of 29.86 kg/mm2 with the tensile strength of the largest specimen of 34.51 kg/mm2 and the tensile strength of the lowest specimen is 25.00 kg/mm2. While on the low carbon steel welding St 37 using RD type electrode has an average power of 31.83 kg/mm2 with the tensile strength of the largest specimen is 34.51 kg/mm2 and the tensile strength of the lowest specimen is 25.81 kg/mm2. Based on the analysis and T test of low carbon steel welding ST 37 using RB type electrode and RD type there is no significant tensile strength difference

Selective laser melting of maraging steel: mechanical properties development and its application in mold

PurposeThis paper aims to verify whether selective laser melting (SLM) could be used for manufacturing mold with conformal cooling channels and determine whether the mechanical properties development of SLM manufacturing maraging steel mold would be beneficial to improve the quality of mold.Design/methodology/approachA series of block specimens and cylindrical tensile specimens are manufactured by SLM, and then are heat treated by solution treatment (ST) and solution treatment + aging treatment (ST + AT), respectively. The development of microstructure, microhardness and tensile strength of specimens is investigated. Then, a mold with conformal cooling channels is designed and manufactured by SLM and machined after ST with microhardness decreasing.FindingsThe morphology of microstructure varies widely under different heat treatment. The microhardness and tensile strength decrease after ST with cellular structure broken, which is conducive to mechanical finishing for mold to improve surface accuracy. After that, the hardness and strength of the mold increase significantly by AT with the precipitation of Ni3Mo, Fe2Mo and Ni3Ti particles. The maraging steel mold with conformal cooling channels can be manufactured by SLM successfully. And the surface accuracy of mold could be improved easily by machining.Originality/valueCompared with the traditional mold with simple cooling channels, the mold with conformal cooling channels can be manufactured by SLM directly. The hardness of maraging steel mold manufactured by SLM can be reduced through ST, which is conducive to mechanical finishing for overcoming the defect of low precision of SLM directly manufacturing mold. This provides a new way for manufacturing mold of high quality.

Evaluation of Strength Properties of Sand Modified with Organic Polymers.

Due to weak physical properties of sand, chemical reinforcement methods are widely used to improve sand properties to meet the engineering requirements. However, most of the traditional additives cause environmental problems. Therefore, non-traditional additives such as liquid polymers, enzymes, ions, and lignin derivatives have been studied extensively. In this study, organic polymer is used as a soil stabilizer to reinforce the sand. To evaluate the effectiveness of the organic polymer as soil stabilizer, a series of unconfined compression strength (UCS) tests, direct shear tests, and tensile tests were carried out on reinforced sand with different polymer concentrations and dry densities of sand. The reinforcement mechanism was analysed with scanning electron microscopy (SEM) images. The results indicated that the polymer concentration and dry density of sand had significant effects on the strength characteristics of reinforced sand specimens. The unconfined compressive strength, cohesion, and tensile strength of specimens with the same dry density increased with the increasing polymer concentration. The polymer membranes—formed by the mixture of polymer and water—enwrap the sand particles and interlink them to form a stable structure. The efficiency of this stabilization changed with dry sand density.

Study of Experiment on Rock-like Material Consist of fly-ash, Cement and Mortar

Study the uniaxial compression test of rock-like material consist of coal ash, cement and mortar by changing the sand cement ratio, replace of fine coal, grain diameter, water-binder ratio and height-diameter ratio. We get the law of four factors above to rock-like material’s uniaxial compression characteristics and the quantitative relation. The effect law can be sum up as below: sample’s uniaxial compressive strength and elasticity modulus tend to decrease with the increase of sand cement ratio, replace of fine coal and water-binder ratio, and it satisfies with power function relation. With high ratio increases gradually, the uniaxial compressive strength and elastic modulus is lower, and presents the inverse function curve; Specimen tensile strength decreases gradually with the increase of fly ash. By contrast, uniaxial compression failure phenomenon is consistent with the real rock common failure pattern.

Behavior of high performance artificial lightweight aggregate concrete reinforced with hybrid fibers

In this investigation, sustainable High Performance Lightweight Aggregate Concrete (HPLWAC) containing artificial aggregate as coarse lightweight aggregate (LWA) and reinforced with mono fiber, double and triple hybrid fibers in different types and aspect ratios were produced. High performance artificial lightweight aggregate concrete mix with compressive strength of 47 MPa, oven dry density of 1828 kg/m3 at 28 days was prepared. The Fibers used included, macro hooked steel fiber with aspect ratio of 60 (type S1), macro crimped plastic fiber (P) with aspect ratio of 63, micro steel fiber with aspect ratio of 65 (type S), and micro polypropylene fiber (PP) with aspect ratio of 667. Four HPLWAC mixes were prepared including, one plain concrete mix (without fiber), one mono fiber reinforced concrete mixes (reinforced with plastic fiber with 0.75% volume fraction), one double hybrid fiber reinforced concrete mixes (0.5% plastic fiber + 0.25% steel fiber type S), and a mix with triple hybrid fiber (0.25% steel fiber type S1+ 0.25% polypropylene fiber + 0.25% steel fiber type S). Fresh (workability and fresh density) and hardened concrete properties (oven dry density, compressive strength, ultrasonic pulse velocity, splitting tensile strength, flexural strength, static modules of elasticity, thermal conductively, and water absorption) were studied. Generally, mono and hybrid (double and triple) fiber reinforced HPLWAC specimens give a significant increase in splitting tensile strength and flexural strength compared with plain HPLWAC specimens. The percentage increases in splitting tensile strength for specimens with mono plastic fiber are, 20.8%, 31.9%, 36.4% and 41%, while the percentage increases in flexure strength are 19.5%, 37%, 33.9% and 34.2% at 7, 28, 60, 90 days age respectively relative to the plain concrete. The maximum splitting tensile and flexure strengths were recorded for triple hybrid fiber reinforced HPLWAC specimens. The percentage increases in splitting tensile strength for triple hybrid fiber reinforced specimens are 19.5%, 37%, 33.9% and 34.2%, while the percentage increases in flexure strength are 50.5%, 62.4. %, 66.8% and 62.2% at 7, 28, 60 and 90 days age respectively relative to the plain concrete specimens.

Effect of electropulsing treatment on microstructure and mechanical behavior of Ti-6Al-4V alloy sheet under argon gas protection

The effect of electropulsing on microstructure and mechanical behavior of Ti-6Al-4V alloy sheet was studied by the electropulsing treatment tests under argon gas protection. Compared to conventional treatment test without current, the specimen tensile strength keeps constant and the maximum plasticity increases by 21.67% with current density of 17.8 A/mm2 under electropulsing treatment. An empirical model to predict the temperature evolution of Ti-6Al-4V sheet under electropulsing was established. To understand the mechanism of electropulsing treatment, the microstructure of electropulisng treated specimens was analyzed. The results show that the electropulsing can accelerate the recrystallization and phase transformation of Ti-6Al-4V under a relatively low temperature compared to heat treatment. The enhancement of elongation at 17.8 A/mm2 is attributed to rapid recrystallization. Based on the contribution of thermal and athermal effect on thermodynamics and kinetics, the mechanism of the electropulsing on the recrystallization and phase transformation are discussed.

Experimental study of the influence of loading rate on tensile mechanical behavior of sandstone damaged by blasting

The drill and blast method (D&B) is perhaps the most common excavation method for rock mass, and intense blasting vibrations would induce an excavation damage zone (EDZ) around the excavated space. The tensile failure of rock mass in EDZ at diverse rupture velocities results in various geological disasters in engineering practices. The objective of this paper is to investigate the effect of blasting on the tensile strength of sandstone rock and the influence of loading rate on the disk specimens affected by blasting. We firstly performed a D&B exercise on a sandstone block with a size of 600 mm × 600 mm × 120 mm. Then, a total number of 49 standard disk specimens were prepared from large fragments of this blasting sandstone block and an undamaged block. A series of Brazilian split tests was carried out using these specimens to determine their indirect tensile strength, and to assess the effects of the distance from the blasting source and loading rate (varying from 1.67 × 10−5 to 8.33 × 10−2 mm s−1). The results show that the tensile strength of specimens exhibits an upward trend with increasing distance from the blasting source, to approach that of undamaged rock, following a power function with a positive exponent (0~1). The loading rate affects the tensile mechanical behaviors of disks, in terms of the convergence of microscopic defects, the main load-bearing area, and the absorbed energy at the fracture moment of specimens. Both the tensile strength and absorbed energy have positive linear correlations with the natural logarithm of the loading rate. In addition, the fragmentation degree of disk specimens also increases due to an increasing brittleness of sandstone with the loading rate.

Influence of scratch type on tensile strength in in situ tensile test

In this article, the specimen of Q235 (low carbon steel, C ≤ 0.22%, Mn: 0.3%–0.8%, Si ≤ 0.3%, P ≤ 0.045%, S ≤ 0.05%) has been tested in in situ tensile tests. Especially, different types of scratches are prefabricated with 1, 2, and 3 µm in depth. In addition, three scratch angles (θ = 0°, 45°, and 90°) are adopted to explore the changes of tensile strength. The cross profile of the scratch groove is measured with in situ observation method (Olympus DSX500), which is taken as an important indicator to verify the experiments. According to the results of experiments, scratch depth and angle can influence the tensile strength of material. When the depth and scratch angle increase, there is a decrement in the value of tensile strength. This indicates that the surface damage really has effect on the tensile strength of specimen.

Experimental investigation of the effect of using different aggregate types on WMA mixtures

In recent years, production of warm mix asphalt (WMA) mixtures with the help of chemical additives has been developed due to obvious advantages, such as reduction of pollution emissions, construction temperature and the possibility of carrying asphalt in long distances. Various additives can have positive or negative effects on the performance characteristics of WMA mixtures made from different types of aggregates. Although, effects of different types of aggregates have been more investigated on the performance of hot mix asphalt (HMA), the effects on WMA have been less studied. Therefore, in this study, three types of aggregates including: limestone (Li), siliceous (Si) and slag (Sl) from the metal production factories together with Sasobit and Zeolite additives were provided to be used for the WMA mixtures. After constructing the asphalt samples and determining the optimum binder, Marshall Stability, indirect tensile strength tests and resilient modulus test and the durability parameter determination were performed. Test results indicated that WMA-Sasobit mixtures have the greatest impact on reducing consumed percentage of binder in slag and siliceous aggregates compared to limestone aggregates. For both additives, WMA mixtures containing limestone aggregates showed higher resilient modulus and siliceous aggregates showed lower resilient modulus. Moreover, the results of indirect tensile strength of specimens containing limestone aggregates showed the highest value and siliceous aggregates showed the lowest one. TSR in the limestone and slag aggregates was improved using both additives, but Zeolite additives reduce TSR in the siliceous aggregates.

Influence of Water Content on Mechanical Properties of Rock in Both Saturation and Drying Processes

Water content has a pronounced influence on the properties of rock materials, which is responsible for many rock engineering hazards, such as landslides and karst collapse. Meanwhile, water injection is also used for the prevention of some engineering disasters like rock-bursts. To comprehensively investigate the effect of water content on mechanical properties of rocks, laboratory tests were carried out on sandstone specimens with different water contents in both saturation and drying processes. The Nuclear Magnetic Resonance technique was applied to study the water distribution in specimens with variation of water contents. The servo-controlled rock mechanics testing machine and Split Hopkinson Pressure Bar technique were used to conduct both compressive and tensile tests on sandstone specimens with different water contents. From the laboratory tests, reductions of the compressive and tensile strength of sandstone under static and dynamic states in different saturation processes were observed. In the drying process, all of the saturated specimens could basically regain their mechanical properties and recover its strength as in the dry state. However, for partially saturated specimens in the saturation and drying processes, the tensile strength of specimens with the same water content was different, which could be related to different water distributions in specimens.

Welding Thermal Crack Sensitivity Simulation of 9%Ni Steel

In this paper, the application of 9% Ni steel in natural gas storage tanks and the welding thermal crack tendency of 9% Ni steel were studied. For the section shrinkage and breaking strength of tensile specimens at different temperature, the high temperature tensile test (600°C~1450°C) of 9%Ni steel was carried out by Gleeble 3500 thermal simulation machine. The nil-ductility transition temperature (NDT), nil-ductility stength temperature (NST) and ductility recovery temperature (DRT) of 9%Ni steel were identified. The result showed that the NDT for 9% Ni steel was 1400°C, the NST was 1430°C, the DRT is 1370°C, and the brittle temperature range (BTR) was 60°C. In this study, the welding hot crack of 9% Ni steel was a little sensitive.

Assessment of effectiveness of rejuvenator on artificially aged porous asphalt concrete

The service life of porous asphalt pavements is limited due to raveling. Preventive maintenance to porous asphalt pavements by means of spraying rejuvenators on the pavement surfaces is considered as cost-effective. In the research of this paper, a loose asphalt mixture was artificially aged and then compacted. A rejuvenator was applied to the prepared porous asphalt concrete specimens. The stiffness modulus and indirect tensile strength of the specimens were measured using the indirect tensile tests. The results show that the application of the rejuvenator did not change the stiffness modulus and indirect tensile strength of the porous asphalt concrete specimens.

Properties Variation of Carbon Fiber Reinforced Composite for Marine Current Turbine in Seawater

Turbine blade which are generally made of composite is a core device among components of tidal current power generator that converts the flow of tidal current into a turning force. Recent years, damages of composite turbine blades have been reported due to reasons like seawater degradation, lake of strength, manufacture etc. In this paper, water absorption, tensile, bending, longitudinal transverse shearing properties of carbon fiber reinforced plastic (CRP) composite which would be applied to fabricate the marine current turbine blade has been investigated. Furthermore, the variations of properties with seawater immersion period were studied. The results indicated that the water absorption increased almost linearly at the beginning of immersion and then became stable. Tensile strength of specimen tended to decrease firstly and then recovered slightly. However, the longitudinal transverse shearing strength showed reverse variation trend comparing to tensile strength. And the bending property of specimens was depressed significantly. The properties variations in seawater shall be referenced to design and fabrication of composite marine current turbine blade.