Alloys for Aeronautic Applications: State of the Art and Perspectives

Gloria, Antonio; Montanari, Roberto; Richetta, M.; Varone, Alessandra

doi:10.3390/met9060662

Cited by 149 publications

(75 citation statements)

References 176 publications

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“…High-strength aluminum alloys have found their application mainly in aerospace and automotive industry, where high specific strength allows to minimalize weight of construction [1][2][3]. Although the strongest of aluminum alloys owe their properties to precipitation hardening process (2xxx and 7xxx series), in recent years, a lot of effort has been undertaken to improve their parameters even further by different means [4,5]. These processes include operations as cryogenic rolling, equal channel angular pressing (ECAP), high-pressure torsion (HPT), accumulative extrusion bonding (AEB) and hydrostatic extrusion (HE) [6][7][8][9][10][11][12][13][14].…”

Section: Introductionmentioning

confidence: 99%

Low Cycle Fatigue Properties of Sc-Modified AA2519-T62 Extrusion

et al. 2020

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This investigation presents the results of research on low cycle fatigue properties of Sc-modified AA2519-T62 extrusion. The basic mechanical properties of the investigated alloy have been established in the tensile test. The low cycle fatigue testing has been performed on five different levels of total strain amplitude: 0.4%; 0.5%; 0.6%; 0.7% and 0.8% with cycle asymmetry coefficient R = 0.1. For each level of total strain amplitude, the graphs of variations in stress amplitude and plastic strain amplitude in the number of cycles have been presented. The obtained results allowed to establish Ramberg-Osgood and Manson-Coffin-Basquin relationships. The established values of the cyclic strength coefficient and cyclic strain hardening exponent equal to k’ = 1518.1 MPa and n’ = 0.1702. Based on the Manscon-Coffin-Basquin equation, the values of the following parameters have been established: the fatigue strength coefficient σ’f = 1489.8 MPa, the fatigue strength exponent b = −0.157, the fatigue ductility coefficient ε’f = 0.4931 and the fatigue ductility exponent c = −1.01. The fatigue surfaces of samples tested on 0.4%, 0.6% and 0.8% of total strain amplitude have been subjected to scanning electron microscopy observations. The scanning electron microscopy observations of the fatigue surfaces revealed the presence of cracks in striations in the surrounding area with a high concentration of precipitates. It has been observed that larger Al2Cu precipitates exhibit a higher tendency to fracture than smaller precipitates having a higher concentration of scandium and zirconium.

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Section: Introductionmentioning

confidence: 99%

Low Cycle Fatigue Properties of Sc-Modified AA2519-T62 Extrusion

et al. 2020

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“…Besides these properties, the non-toxicity of titanium makes it also useful for biomedical applications (implant devices, pacemakers, artificial hearts) [2]. However, the high hardness and low machinability of Ti alloys affect their feasibility by conventional processes [3], encouraging the research for new methods, as pointed out in Reference [4], for vibration cutting. Machinability problems can be overcome by additive manufacturing, that includes a variety of technologies, applied for more than 20 years for porous structures and prototypes, some of which promise to become commonly used to produce near-net-shape components of complex geometry reducing production time and cost [5].…”

Section: Introductionmentioning

confidence: 99%

Tensile and Creep Properties Improvement of Ti-6Al-4V Alloy Specimens Produced by Electron Beam Powder Bed Fusion Additive Manufacturing

Aliprandi

Giudice

Guglielmino

et al. 2019

Metals

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Thanks to their excellent mechanical strength in combination with low density, high melting point, and good resistance to corrosion, titanium alloys are very useful in many industrial and biomedical fields. The new additive manufacturing methods, such as Electron Beam Powder Bed Fusion based on the deposition of metal powders layers progressively molten by electron beam scanning, can overcome many of the machining problems concerning the production of peculiar shapes made of Ti alloys. However, the processing route is strictly determinant for mechanical performance of products, especially in the case of Ti alloys. In the present work flat specimens made of Ti-6Al-4V alloy produced by Electron Beam Powder Bed Fusion (or Electron Beam Melting) have been built and post-processed with the purpose of obtaining good tensile and creep performance. Preliminarily, the process parameters were set according to literature evidence and machine producer recommendations, validated by the results of a thermal analysis, aimed at satisfying the best processing conditions to reduce defects, as unmelted regions, microstructure coarsening or porosity, that are detrimental to mechanical behavior. Subsequently, Hot Isostatic Pressing and surface smoothing were considered, respectively, in order to reduce any internal porosity and lower roughness. Microstructure of the investigated specimens was characterized by optical and scanning electron microscopy observations and by X-ray diffraction measurements. Results show enhanced tensile behavior after the hot pressing treatment that allows to relieve stresses and reduce defects detrimental to mechanical properties. The best ductility was obtained by the combined effects of machining and densification. Creep test results verify the beneficial effects of surface smoothing.

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“…The book gathers manuscripts from academic and industrial researchers with stimulating new ideas and original results. It consists of one review paper regarding state of art and perspectives of alloys for aeronautic applications [1] and fifteen research papers [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16] focused on different materials and processes.…”

Section: Contributionsmentioning

confidence: 99%