Brittle Fracture
Mostrando 13-24 de 60 artigos, teses e dissertações.
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13. Platinum-Based Alloys: Investigation of the Effect of Impurities Content on Creep Rate, Rupture Time and Relative Elongation at High Temperatures
This paper presents the results of research of the effect of impurities content on high-temperature resistance of selected platinum alloys. Alloys of following systems were investigated: Pt-Rh, Pt-Rh-Pd, Pt-Rh-Pd-Ru and Pt-Rh-Pd-Ir-Au. Universal device for tensile testing of materials at high temperatures was used for examination. Investigations were carried
Mat. Res.. Publicado em: 05/01/2017
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14. Estimation of the Fracture Toughness Threshold of a Ferritic Steel at the Lower Ductile to Brittle Transition Region
The ADN420 ferritic steel (A615 steel Grade 60 [420]), used as reinforcing bars (rebar) in concrete, shows the so called ductile to brittle transition. Room temperature is located on the lower third region of the transition zone. In this work, the fracture toughness of this steel working at room temperature was studied statistically. For such a purpose, 125
Mat. Res.. Publicado em: 18/08/2016
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15. Effect of Al addition to Rapidly Solidified Mg-Cu-Rare Earth Alloys
Rapidly solidified Mg based alloys are of interest for industrial applications as a structural material and for hydrogen storage. Mg-Cu-Rare Earth alloys have shown high glass forming ability; full amorphous structure with thickness of mm size can be obtained within these systems. However, their brittle behavior limits their industrial applications. In the p
Mat. Res.. Publicado em: 03/06/2016
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16. Charpy Impact Tests of Epoxy Composites Reinforced with Giant Bamboo Fibers
The giant bamboo fiber is among the strongest in the Bambusa species with a potential for application as engineering material. Its properties have been evaluated but there is limited information on the impact resistance of epoxy composites incorporated with giant bamboo fibers. Therefore, this study evaluated the Charpy impact energy of epoxy matrix composit
Mat. Res.. Publicado em: 04/12/2015
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17. Thermal Stability and the Matrix Induced Brittleness in a Ti-based Bulk Metallic Glass Composite
Crystallization kinetics and nanocrystalline induced brittleness in an in-situ dendrites reinforced Ti44Zr20Nb12Cu5Be19 bulk metallic glass (BMG) composites were investigated. The activated energy of the present Ti-based metallic glass matrix is obtained to be about 201 KJ/mol. As the annealing temperature rises, the annihilation of free volume is believed t
Mat. Res.. Publicado em: 17/11/2015
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18. A New Displacement-based Approach to Calculate Stress Intensity Factors With the Boundary Element Method
Abstract The analysis of cracked brittle mechanical components considering linear elastic fracture mechanics is usually reduced to the evaluation of stress intensity factors (SIFs). The SIF calculation can be carried out experimentally, theoretically or numerically. Each methodology has its own advantages but the use of numerical methods has become very popu
Lat. Am. j. solids struct.. Publicado em: 2015-09
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19. Interaction Analysis of Non-aligned Cracks Using Extended Finite Element Method
Abstract Multiple flaws are frequently occurred in actual components, such as pressure vessels and power plants. These flaws will in some circumstances lead to more severe effects than single flaw alone. Assessment of the interaction behavior is based on the evaluation of alignment and combination of these multiple flaws. In the current standards, multiple c
Lat. Am. j. solids struct.. Publicado em: 2015
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20. Mechanical and microstructural characterization of Nodular Cast Iron (NCI) with Niobium Additions
Nodular cast irons (NCIs) involve the inoculation and nodulization of 0.03 to 0.06wt% Magnesium, as well as the addition of Molybdenum, Chromium, Nickel, Copper and Vanadium, although the presence of Niobium is not common. The literature reports that Niobium leads to better mechanical properties of the NCIs, and recent results indicate that 0.5wt% Niobium in
Mat. Res.. Publicado em: 2014-10
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21. Mechanical properties of castor oil polymer mortars
In the last years, ecological concerns have resulted in the interest to substitute petroleum-based materials by renewable resources-based ones. Natural oils constitute an excellent alternative for the development of natural composites. The aim of this work is to evaluate the use of natural polymer, manufactured from castor oil, as substitute to synthetic, ep
Mat. Res.. Publicado em: 22/09/2014
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22. Workhardening behaviour and microstructural analysis of failed austenitic manganese steel crusher jaws
This study focussed on the work hardening behaviour and microstructure of austenitic manganese steel relative to premature failure of crusher jaws. Samples of sound and failed crusher jaws were taken, the change with depth from the working surface to the sample core was measured and their microstructures observed. The study revealed a sharp hardness gradient
Mat. Res.. Publicado em: 03/09/2013
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23. Influence of welding parameters and post-weld aging on tensile properties and fracture location of AA2139-T351 friction-stir-welded joints
Tensile properties and fracture location of AA2139-T351 friction stir welded joints are studied in the as-welded and post-weld aged condition. The experimental results show that when the joints are free of welding defects, they fail on the advancing side of the HAZ exhibiting a large amount of plastic deformation. When the revolutionary pitch exceeds a thres
Mat. Res.. Publicado em: 25/06/2013
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24. Normalizing effect on fatigue crack propagation at the heat-affected zone of AISI 4140 steel shielded metal arc weldings
The fractography and mechanical behaviour of fatigue crack propagation in the heat-affected zone (HAZ) of AISI 4140 steel welded using the shielded metal arc process was analysed. Different austenitic grain size was obtained by normalizing performed at 1200 °C for 5 and 10 hours after welding. Three point bending fatigue tests on pre-cracked specimens along
Mat. Res.. Publicado em: 02/04/2013