Martensitic Transformations
Mostrando 1-12 de 12 artigos, teses e dissertações.
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1. Evaluation of two-step transformation in Ni-rich titanium-nickel alloys using thermal and internal friction analyses
ABSTRACT The use of Ti-Ni memory alloys covers several fields of application such as medicine, dentistry, actuators, sensors among others. Because of the thermomechanical behavior of these materials, they are an object of continuous studies and their properties are related to the occurrence of thermoelastic martensitic phase transformations. The thermal anal
Matéria (Rio J.). Publicado em: 16/09/2019
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2. Structural and Magnetic Properties of Duplex Stainless steel (UNS S31803) Powders Obtained by high Energy Milling of Chips with Additions of NbC
In this study, the high energy mechanical milling was utilized to the production of duplex stainless steel powders from the recycling chips with and without the addition niobium carbide. The effect of milling time and addition carbide on the morphology, particle size and magnetic properties of the powders was investigated. The utilization of the powder metal
Mat. Res.. Publicado em: 30/10/2017
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3. The Influences of Martensitic Transformations on Cavitation-Erosion Damage Initiation and Pitting Resistance of a Lean Austenitic Stainless Steel
This paper looks into the influences of martensitic transformations on the cavitation-erosion (CE) damage initiation mechanism and pitting corrosion resistance of a lean austenitic stainless steel. The ε and α' martensites are prime sites of CE damage initiation for this steel, whereas grain boundaries are more favourable damage initiation sites for other
Mat. Res.. Publicado em: 03/10/2016
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4. Corrosion and microstructural characterization of martensitic stainless steels submitted to industrial thermal processes for use in surgical tools
INTRODUCTION: The mechanical properties and corrosion resistance of a material are dependent on its microstructure and can be modified by phase transformation. When a phase transformation occurs in a material it usually forms at least one new phase, with physical-chemical characteristics that differ from the original phase. Moreover, most phase transformatio
Rev. Bras. Eng. Bioméd.. Publicado em: 2014-09
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5. ECAE processed NiTi shape memory alloy
The current work evaluated the microstructures and martensitic transformation temperatures of NiTi shape memory alloy (SMA) deformed by equal channel angular extrusion (ECAE). The Ti-55.27wt.%Ni alloy was processed by 1 ECAE pass at 250 °C using a die with an intersection angle of 120°. After processing, samples were annealed at 300 °C, 400 °C and 500 °
Mat. Res.. Publicado em: 25/03/2014
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6. Martensitic transformation induced by cold deformation of lean duplex stainless steel UNS S32304
Lean duplex UNS S32304 is an austenitic ferritic stainless steel with pitting resistance equivalent number around 24-25. Its corrosion resistance is similar to AISI 316L steel, but with the advantage of a yield limit two times superior to conventional austenitic grades. Deformation induced martensitic transformations (γ→ε and γ→ α') have been extensi
Mat. Res.. Publicado em: 27/09/2013
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7. Analysis of the transformations temperatures of helicoidal Ti-Ni actuators using computational numerical methods
The development of shape memory actuators has enabled noteworthy applications in the mechanical engineering, robotics, aerospace, and oil industries and in medicine. These applications have been targeted on miniaturization and taking full advantage of spaces. This article analyses a Ti-Ni shape memory actuator used as part of a flow control system. A Ti-Ni s
Mat. Res.. Publicado em: 10/05/2013
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8. Heat treatments and thermomechanical cycling influences on the R-phase in Ti-Ni shape memory alloys
This article studies changes observed on the R-phase thermoelastic behavior in a near-equiatomic Ti-Ni shape memory alloy. Three kinds of procedures have been performed: different treatments, thermomechanical cycling under constant loading in shape memory helical springs and thermal cycling in as-treated and trained samples. Several heat treatments were carr
Materials Research. Publicado em: 2010-09
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9. Electro-thermomechanical properties of superelasticity in single crystals shape memory alloys
In this work, superelastic behavior of single crystals shape memory alloys has been investigated by the electric resistivity (ER) measure technique coupled simultaneously during traction tests. Samples in austenitic phase were submitted to stress induced martensite (SIM) under several conditions such as: different temperatures, different deformation rate, th
Materials Research. Publicado em: 2010-06
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10. Phase transformation studies af a low alloy steel in the (α + γ) phase region
This research work describes a thermo mechanical investigation of a low alloy steel treated in the (α + γ) phase region. The aim is to develop a high tensile, ductile microstructure that could have a wide range of engineering applications. Recent advances in the area of precipitation, recrystallization mechanisms, and α / γ transformations provide strong
Materials Research. Publicado em: 2010-03
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11. Analysis of the application potentiality of nodular cast iron ASTM A536 60-40-18 as raw material for thixoforming processes / Estudo da potencialidade da aplicação do ferro fundido nodular ASTM A536 60-40-18 como materia prima para processos de tixoconformação
This work analyses the thixoability, the viability of actual production of thixotropic semi-solid of ferritic nodular cast iron ASTM A536 60-40-18, as well as the phase transformations taking place in the process. Thixoability evaluation is made through thermal analysis by Differential Thermal Analysis (DTA) and Differential Scanning Calorimetry (DSC) tests
Publicado em: 2009
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12. CaracterizaÃÃo termoelÃstica de atuadores helicoidais da liga Cu- Zn-AI com memÃria de forma
O advento dos materiais inteligentes ocorreu devido à crescente corrida tecnolÃgica com a introduÃÃo de novas tÃcnicas para o desenvolvimento de novos materiais capazes de proporcionar a produÃÃo de dispositivos heterodoxos resultando em melhorias funcionais aliadas a miniaturizaÃÃo e simplificaÃÃo. Esses dispositivos desenvolvidos a partir desses
Publicado em: 2007