Papers by Keyword: Elongation

Abstract: We recently proposed a new mechanism to simultaneously improve the strength and ductility of multiphase alloys, named “Anisotropic mechanical property-induced ductilization (AMID)”. In this paper, the variations in tensile deformation behavior of Mg/LPSO extruded alloys depending on the volume fraction of the LPSO phase were examined, to deepen the understanding on AMID. As expected, the work-hardening rate of the Mg/LPSO two-phase extruded alloy increased as increasing in the volume fraction of LPSO phase. This demonstrates the validity of the AMID mechanism. However, the increase in the volume fraction of the LPSO phase decreased the elongation, even though the work-hardening rate was increased in them. The present study revealed that an appropriate amount of Mg grains is necessary to obtain the effect of AMID in improving the uniform elongation of the alloy, by the suppressing the development of microcracks formed in the LPSO phase grains into macroscopic fracture.

Abstract: Mg-Al-Zn alloy, an Mg alloy having Al and Zn as the major constituents, is exceptionally lightweight and has potential to become an essential component of modern engineering applications and healthcare systems. This paper presents valuable insights to the friction stir processing (FSP) applied to Mg-Al-Zn alloy in dry conditions. FSP induced extreme plastic deformation in the metal alloy which causes substantial microstructural alterations. These changes were investigated using optical microscope. Microstructural evaluation of FSP-processed zone indicated that average grain diameter of the FSP-processed zone increased in proportion to tool rotating speed. This is attributed to the frictional zone's degree of plastic deformation. In alignment with results obtained from optical microscopy, morphological study conducted using scanning electron microscope (SEM) also demonstrated the synthesis of refined grains. In addition, the study includes evaluation of the FSP-processed alloy's micro-hardness and tensile characteristics in contrast to the base (unprocessed) alloy.

Abstract: Plasma and TIG arc welding they are similar welding processes for the base of plasma welding is tig welding. The main purpose of this paper to come to a detailed conclusion based on a comparative analysis of both welding processes. The analysis is done steel bars each applied with the particular welding technique either plasma or tig welding. The principles of each welding procedure are discussed on how they welding is carried out, the mechanics and the technological functions of the welding devices are also discussed. The time required to complete a weld, the amount of current used. Impact on the steel is investigated caused by each welding processes. The welded joints are tested for bending and how much they elongate when under bending stress. The welded joints are done as butt welds for both of the grouped steel bars. These welding processes are used in industries where precision is of great importance like aerospace, design of industrial machinery, ship construction and Petro chemical industries. The concluded results of this paper will be of great contribution to the manufacturing industries because they would be able to know which welding process is best for which particular case or both must be used in order to achieve an ideal outcome. Keywords: Plasma and Tungsten inert gas TIG welding arc, tensile mild Steel bars, bending, butt weld, Amount of current, elongation.

Abstract: Rice straw and rice husk fibers (RS/RH) reinforced polymer-based composites have theability to conserve wood and petroleum resources. As natural filler, rice straw and rice husk offer asustainable material for the production of polymer-based composites. The application ofbiocomposite limits the burning of straw at the root and may further enhance the socioeconomicstatus of farmers and rural populations. This review mainly focuses on five different weightpercentage of reinforced RS and RH fiber content (5%, 10%, 15%, 20% and 25%) in polymercomposites. Nowadays, Epoxy, polyurethane, polyester, PVA, PLA and polyethylene are beingused as matrix material in polymer composites. This paper holds good with understanding themechanical properties, pretreatment methods and offer important insight into potential uses ofpolymer composites with biodegradable reinforce fiber.

Abstract: This paper presents the results of a study of changes in mechanical properties, namely tensile strength, yield strength and elongation when drawing a wire from NP2 nickel (Ni 99.6). The wire samples taken along the drawing route were tested for tension. Based on the test results obtained, graphs of changes in tensile strength, yield strength and elongation were plotted depending on cold work. The approximation of the graphs made it possible to obtain equations for the change in tensile strength (UTS), yield strength (0.2 US) and elongation (δ) depending on cold work (ɛ∑). The obtained dependences are recommended to be used to predict the mechanical properties of nickel wire during drawing and when developing software for designing resource-saving drawing routes.

Abstract: Treatment of the slurry is important during RheoMetal^TM casting. In this work, semi-solid slurries were prepared under different stirring intensities, using two types of stirrers: a naked rod (for regular stirring) and a rod with two blades (for intensified stir). Tensile tests were performed, investigating fracture surfaces, as well as metallographic samples. The results show that intensified stir produces castings with finer primary particles and a more homogeneous microstructure. On the other hand, more faceted Fe-rich phases are found along the α-Al grains boundary as well, due to the dissolution of Fe from the stirrers. Moreover, for intensified stir castings, the porosity found on the fracture surfaces are smaller, while more brittle eutectic phases and second (intermetallic) phases, especially Fe-rich phases, are observed. Consequently, the castings with intensified stir show worse ductility. Finally, a quantitative analysis was made regarding ductility, affected both by porosity and the presence of Fe-rich phases.

Abstract: This paper is devoted to obtaining and investigating polymer composites based on polyamide-6 and carbon nanotubes. Polyamide 6, type 210/310, was used as a polymer matrix, and carbon nanotubes manufactured by OcSiAl were used as a modifier. The components were compounded in a co-rotating twin-screw extruder HAAKE Rheomex OS PTW 16 to obtain granulate. The granulate was processed by injection molding on a Babyplast 6/10V machine to obtain test samples as double-sided blades (ISO-527-2, type 5A). Elastic strength tests were carried out on a Gotech UAI-7000M universal tensile-testing machine. It has been shown that introduction of 0.15% CNT promotes an increase in the yield point and the initial modulus of elasticity with a significant decrease in the ultimate strength. The maximum value of the tensile strength (161 MPa) has been obtained for the specified composition at an injection rate of 12.9 ml/s.

Abstract: This paper compares the stress and strain behaviour of mechanical fasteners and elastic adhesive connections in timber façade applications. Two common designs with timber cladding are introduced. The traditional façade planks and multilayer large-format solid wood panels were selected. The resistance of a reference façade section with mechanical fasteners or adhesive bond to wind suction is determined according to the recommendations of European guideline ETAG 034. The pressure/suction chamber allowing hermetic closure was used. The sample deformation was measured at 15 locations, this also allowed to determine the elongation of the adhesive layer at break. The failure loads reached with the adhesive joint exceeded 20 kN/m² in both combinations of façade cladding. On the other hand, the sample with a large-format panel and mechanical fasteners showed the lowest failure load at 12 kN/m². The results confirmed that bonded joints are a suitable solution for large-format cladding, whereas an increase in the number of mechanical fasteners will be a more convenient solution for façade plank applications.

Abstract: The extensive range of fillers used nowadays indicated the major significance of filler in the plastic industry. Although their original purpose was to lower the cost of the molding compounds; prime importance is now attached to selective modification of the properties of a specific plastic. In this study, the examples of LDPE/EVA blends, were put into 0, 3, 6, 9, 12 and 15 wt.% of EVA. The tensile strength, bending strength and impact strength of samples were determined according to ASTM D638, ISO 178 and ISO 179. Results showed that when increasing ratio of EVA in LDPE/ EVA blends, tensile strength decreased from 10.9 MPa to 8.6 MPa. Bending strength decreased linearly from 9.63 MPa to 5.46 MPa. Charpy impact strength decreased from 47.5 kJ/m² to 6.3 kJ/m². On the contrary, elongation in 100% LDPE is 78.3%; with the appearance of EVA, elongation of the LDPE/ EVA blends increased upto 109.1%. In addition, SEM micrographs indicated that, it was more crystal-clear when the EVA content is less; in the highest EVA content with 15%, it can be seen that the specimen after pressing is slightly opaque and darker than the orthers. From that showed the addition of EVA to the polymer leads the tensile strength, bending strength were not affect much, impact strength decreased but elongation experienced an increase.

Abstract: The study reveals the effect of Mn and Mg content on mechanical and technological properties during the bending of thin sheets of aluminum alloy 3005. For experimental research the ingots were cast through an out-of-furnace refining unit, homogenized at a temperature of 590°C, during 6 hours. Further ingots were hot rolled to a thickness of 3.5 mm and subsequently cold rolled into sheets of thickness 0.33 and 0.25 mm. Annealing of rolls was provided at temperatures 230...285°C for 1.5 hour in air-circulation annealing furnaces with a protective atmosphere and on a continuous heat treatment line. The change in the tensile strength, yield stress, elongation as a dependence on the content of alloying elements and annealing modes was shown. Technological properties were evaluated by performing bend tests. It has been established that an increased content of magnesium and manganese in the AA3005 alloy results in lower values of the elongation for all annealing temperatures. Annealing in the air-circulation annealing furnaces resulted to higher plasticity values and lower values of strength compared to annealing at continuous heat treatment line for all annealing temperatures and magnesium and manganese temperatures. The plasticity of samples 0.25 mm thick raises evenly throughout the annealing temperature range. For specimens 0.33 mm thick, the effect of the magnesium and manganese content, as well as the type of heat-treatment equipment on the samples’ plasticity during annealing is more pronounced than for samples 0.25 mm thick. In sheet samples from the AA3005 alloy annealed on continuous heat treatment line, with an increased content of magnesium and manganese, cracks are observed at the inflection point for both thicknesses. When annealing in air-circulation annealing furnaces, cracks are not observed for both increased and reduced magnesium and manganese content.