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Phase transformation and residual stress probed by Raman spectroscopy in diamond-turned single crystal silicon

JASINEVICIUS, R. G.; Duduch, Jaime Gilberto; MONTANARI, L.; PIZANI, P. S.
Fonte: PROFESSIONAL ENGINEERING PUBLISHING LTD Publicador: PROFESSIONAL ENGINEERING PUBLISHING LTD
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
66.07%
Single-point diamond turning of monocrystalline semiconductors is an important field of research within brittle materials machining. Monocrystalline silicon samples with a (100) orientation have been diamond turned under different cutting conditions (feed rate and depth of cut). Micro-Raman spectroscopy and atomic force microscopy have been used to assess structural alterations and surface finish of the samples diamond turned under ductile and brittle modes. It was found that silicon undergoes a phase transformation when machined in the ductile mode. This phase transformation is evidenced by the creation of an amorphous surface layer after machining which has been probed by Raman scattering. Compressive residual stresses are estimated for the machined surface and it is observed that they decrease with an increase in the feed rate and depth of cut. This behaviour has been attributed to the formation of subsurface cracks when the feed rate is higher than or equal to 2.5 mu m/rev. The surface roughness was observed to vary with the feed rate and the depth of cut. An increase in the surface roughness was influenced by microcrack formation when the feed rate reached 5.0 mu m/rev. Furthermore, a high-pressure phase transformation induced by the tool/material interaction and responsible for the ductile response of this typical brittle material is discussed based upon the presented Raman spectra. The application of this machining technology finds use for a wide range of high quality components...

Phase transformation studies in U–Nb–Zr alloy.

Lopes, Denise Adorno; Restivo, Thomaz Augusto Guisard; Padilha, Angelo Fernando
Fonte: Amsterdam Publicador: Amsterdam
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
66.12%
Phase transformation diagrams provide fundamental informations for designing thermomechanical processes being a must regarding uranium alloys nuclear fuels. The work shows the evaluation of a kinetic transformation diagram for U–7.5Nb–2.5Zr (wt.%) based on both calorimetry experiments and dilatometry allied to X-ray diffraction analysis. Calorimetry measurements in scanning and drop modes can detect enthalpies of heating and transformation onset points from ambient up to select isotherms while the dilatometer is used to scan for sample volume changes related to phase transformations. The resulted kinetic diagram shows the gamma phase is stable for this alloy, guiding the rolling deformation process to temperature ranges where this phase remains for longer periods. Comparing to the literature results, the low temperature transformation (300–400 °C) is shifted to longer times accordingly to the disclosed TTT kinetic diagram. Therefore, two forming process windows can be proposed at 200 °C and 400 °C neighborhood where gamma-phase remains for enough time to accomplish total reduction

Modelamento numérico-computacional das transformações de fase nos tratamentos térmicos de aços.; Modelling of phase transformations in heat treatment of steels.

Bortoleto, Eleir Mundim
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 23/07/2010 PT
Relevância na Pesquisa
56.06%
Neste trabalho, propõe-se um modelo numérico-computacional representativo dos processos de tratamento térmico, que seja uma ferramenta eficiente e forneça meios para um entendimento efetivo do mecanismo de geração de tensões residuais durante a têmpera de aços. Foram investigados os fenômenos térmicos, mecânicos e de transformação de fase observados na têmpera, bem como o acoplamento entre esses três fenômenos. O modelo utiliza o Método dos Elementos Finitos (MEF) e o programa ABAQUS®, além de rotinas numéricas em FORTRAN responsáveis pela resolução do problema termo-mecânico-microestrutural acoplado. A utilização de sub-rotinas, que implementam uma alteração na formulação (matemática e numérica) do programa de Elementos Finitos, permite incluir no modelo as informações presentes em uma curva CRC (curva de resfriamento contínuo) do aço SAE 4140, implementando o cálculo de deformações da peça simulada de modo incremental e cumulativo. Os resultados mostram que a utilização das sub-rotinas desenvolvidas neste trabalho permitiu implementar, conjuntamente com o programa ABAQUS®, o cálculo das frações volumétricas, durezas, distorções e tensões que surgem em um tratamento térmico de têmpera...

Estudo da cinética da transformação de fase no estado sólido UAl3 + Al → UAl4; Kinetics of solid state phase transformation UAl3 + Al → UAl4

Cunha, Cecilio Alvares da
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 10/04/1987 PT
Relevância na Pesquisa
55.98%
A cinética da transformação de fase UAl3 + Al → UAl4 foi estudada em duas ligas Al-U, com 31,4 % e 33,4 % U em peso respectivamente, através de metalografia quantitativa. Os resultados mostraram que esta transformação é um processo de nucleação e crescimento termicamente ativado, com a nucleação ocorrendo heterogeneamente nas interfaces UAl3/AI(∞) e o crescimento sendo controlado por difusão em volume. A energia de ativação empírica do processo foi determinada, cujo valor médio é da ordem de 54,8 kcal/mol. Foi verificado que a cinética de crescimento da fase UAl4 obedece uma lei parabólica. As interfaces UAl4/ UAl3 e UAl4/Al(∞) migram em direções opostas, sendo que a velocidade da interface UAl4/ UAl3 é aproximadamente cinco vezes maior que aquela da interface UAl4/Al(∞). O coeficiente de difusão química do Al e do U na fase UAl4 foi avaliado ser da ordem de 10-9 cm 2/s a 600°C.; The kinetics of phase transformation UAl3 + Al → UAl4 of two Al-U alloys, with 31.4 and 33.4 wt % U respectively, was studied by quantitative microscopy. The results have shown that this transformation is a nucleation and thermally activated growth process. The nucleation occurs heterogeneously at the UAl3/AI(∞) interfaces and growth is controlled by volume diffusion. The empirical activation energy of the process was determined...

Role of the oriented attachment mechanism in the phase transformation of oxide nanocrystals

Ribeiro, Caue; Vila, Cristiane; de Matos, Jose Milton Elias; Bettini, Jefferson; Longo, Elson; Leite, Edson R.
Fonte: Wiley-Blackwell Publicador: Wiley-Blackwell
Tipo: Artigo de Revista Científica Formato: 5798-5803
ENG
Relevância na Pesquisa
55.95%
Bottom-up methods to obtain nanocrystals usually result in metastable phases, even in processes carried out at room temperature or under soft annealing conditions. However, stable phases, often associated with anisotropic shapes, are obtained in only a few special cases. In this paper we report on the synthesis of two well-studied oxides-titanium and zirconium oxide-in the nanometric range, by a novel route based on the decomposition of peroxide complexes of the two metals under hydrothermal soft conditions, obtaining metastable and stable phases in both cases through transformation. High-resolution transmission electron microscopy analysis reveals the existence of typical defects relating to growth by the oriented attachment mechanism in the stable crystals. The results suggest that the mechanism is associated to the phase transformation of these structures.

Phase Transformation in Titania Nanocrystals by the Oriented Attachment Mechanism: The Role of the pH Value

Ribeiro, Caue; Barrado, Cristiano M.; Camargo, Emerson R.; Longo, Elson; Leite, Edson R.
Fonte: Wiley-v C H Verlag Gmbh Publicador: Wiley-v C H Verlag Gmbh
Tipo: Artigo de Revista Científica Formato: 2217-2222
ENG
Relevância na Pesquisa
55.91%
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); A new synthetic method for TiO2 nanocrystals starting from metallic Ti and hydrogen peroxide was developed. in order to obtain minimal interferences to evaluate phase transformation in the system. The results revealed that the crystal morphology appeared to be dictated by the pH value, which shows a strong dependence oil the surface energy. The involvement of the oriented attachment (OA) mechanism is important to modify the morphology and, hence, the distribution of the surface energy and confirmed that the mechanism can accelerate certain phase transitions, albeit pH dependence in terms of how the mechanism affects the final particle morphology and direction of crystalline growth. The importance of the mechanism was also apparent in extremely basic conditions, which indicates a possible correlation with the formation of hydrogen titanate nanostructures.

Influence of silver additions on the structure and phase transformation of the Cu-13 wt % Al alloy

Arruda, G. J.; Adorno, A. T.; Benedetti, A. V.; Fernandez, J.; Guilemany, J. M.
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 6299-6303
ENG
Relevância na Pesquisa
55.94%
The influence of silver additions on the structure and phase transformation of the Cu-13 wt % Al alloy was studied by differential thermal analysis, X-ray diffraction, scanning electron microscopy and energy dispersive analysis of X-rays. The results indicate that the presence of silver modifies the phase-stability field, the transition temperature and the structure of the alloy. These effects are more pronounced for silver concentrations up to 8 wt %.

Extrusion of poly(vinylidene fluoride) filaments : effect of the processing conditions and conductive inner core on the electroactive phase content and mechanical properties

Ferreira, A.; Costa, Pedro; Carvalho, Helder; Nóbrega, J. M.; Sencadas, V.; Lanceros-Méndez, S.
Fonte: Springer Publicador: Springer
Tipo: Artigo de Revista Científica
Publicado em 07/02/2011 ENG
Relevância na Pesquisa
56.02%
The phase transformation from the α- to the electroactive β-phase of poly(vinylidene fluoride) (PVDF) extruded filaments submitted to different stretching conditions was investigated. Sample filaments of α-PVDF thermoplastic were extruded and stretched uniaxially at different temperatures (80 ºC to 120 ºC) and stretch ratios (1 to 6). The stretched samples were studied and characterised by x-ray diffraction and quasi-static mechanical experiments. High β-phase contents (~ 80%) are achieved using a stretch ratio of 5 independently of the stretching temperature, between 80 ºC and 120 ºC. Subsequently, in order to obtain filament geometries and material configurations suitable for application, a two layer filament with coaxial layers was produced by coextrusion. The inner layer consisted of a commercially available grade of a conductive thermoplastic with a polypropylene (PP) matrix. For the outer layer the same grade of PVDF was employed. The double-layer filament was also stretched under the same conditions of the PVDF filaments and the results obtained shows that the inner layer material, acting as an electrode, does not have any influence in the PVDF crystallization process: PVDF crystallizes in the α-phase for stretch ratios of 1 and the α to β-phase transformation occurs for higher stretch ratios.; Fundação para a Ciência e a Tecnologia (FCT)

Formation of welding residual stresses in low transformation temperature (LTT) materials

Kannengiesser,Thomas; Kromm,Arne
Fonte: Associação Brasileira de Soldagem Publicador: Associação Brasileira de Soldagem
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/03/2009 EN
Relevância na Pesquisa
56.06%
For the safety and cost efficiency of welded high-strength steel structures, precise knowledge of the level and distribution of welding- and cooling-specific stresses and residual stresses is essential, since they exert a decisive influence on strength, crack resistance, and finally on the bearable service load. This paper presents innovative filler materials, of which the phase transformation temperature was deliberately adjusted via the chemical composition. The transformation behaviour of these martensitic Low Transformation Temperature (LTT-) filler materials shows direct effects on the local residual stresses in the weld and the HAZ. These effects can purposefully be exploited to counteract the thermally induced shrinkage of the material and to produce significant compressive residual stresses in the weld. Comparative welding experiments were carried out on 690 MPa high-strength base materials using various LTT-filler materials. High energy synchrotron radiation was used for residual stress measurement. Particularly the use of high energy synchrotron radiation makes it possible to detect the residual stress condition fast without destruction of material. Thereby, residual stress depth gradients can be determined simultaneously without removing material. In steel...

In-situ-phase analysis using synchrotron radiation of low transformation temperature (LTT) welding material

Kromm,Arne; Kannengiesser,Thomas
Fonte: Associação Brasileira de Soldagem Publicador: Associação Brasileira de Soldagem
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/03/2009 EN
Relevância na Pesquisa
56.12%
Cold cracking resistance is a relevant evaluation criterion for welded joints and affected by residual stresses which result from the welding procedure. Compressive residual stresses can thereby have a positive influence on preventing cracking. A unique possibility of generating compressive residual stresses already during the welding procedure is offered by the so-called Low Transformation Temperature (LTT) filler wires. Compared to conventional wires, these materials show decreased phase transformation temperatures which can work against the cooling-specific contraction. In consequence, distinct compressive residual stresses can be observed within the weld and adjacent areas. The strength of these fillers makes them potentially applicable to high-strength steel welding. Investigations were carried out to determine the phase transformation behaviour of different LTT-filler materials. Transformation temperatures were identified using Single Sensor Differential Thermal Analysis (SS-DTA). Additionally Synchrotron radiation was used to measure the transformation kinetics of all involved crystalline phases during heating and cooling of a simulated weld thermal cycle.

Liquid phase sintered SiC. Processing and transformation controlled microstructure tailoring

Izhevskyi,V.A.; Genova,L.A.; Bressiani,A.H.A.; Bressiani,J.C.
Fonte: ABM, ABC, ABPol Publicador: ABM, ABC, ABPol
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/10/2000 EN
Relevância na Pesquisa
56.12%
Microstructure development and phase formation processes during sintering of silicon carbide based materials with AlN-Y2O3, AlN-Yb2O3, and AlN-La2O3 sintering additives were investigated. Densification of the materials occurred by liquid-phase sintering mechanism. Proportion of alpha- and beta-SiC powders in the initial mixtures was a variable parameter, while the molar ratio of AlN/RE2O3, and the total amount of additives (10 vol. %) were kept constant. Shrinkage behavior during sintering in interrelation with the starting composition of the material and the sintering atmosphere was investigated by high temperature dilatometry. Kinetics of b-SiC to a-SiC phase transformation during post-sintering heat treatment at temperatures 1900-1950 °C was studied, the degree of phase transformation being determined by quantitative x-ray analysis using internal standard technique. Evolution of microstructure resulting from beta-SiC to alpha-SiC transformation was followed up by scanning electron microscopy on polished and chemically etched samples. Transformation-controlled grain growth mechanism similar to the one observed for silicon nitride based ceramics was established. Possibility of in-situ platelet reinforced dense SiC-based ceramics fabrication with improved mechanical properties by means of sintering was shown.

Influence of deformation on the kinetics of phase transformation in a forging steel during warm working

Oliveira,Mauro Aparecido Ferreira de; Jorge Jr,Alberto Moreira; Balancin,Oscar
Fonte: ABM, ABC, ABPol Publicador: ABM, ABC, ABPol
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2004 EN
Relevância na Pesquisa
56.04%
Dilatometric techniques were used to determine the start and finish transformation heating temperatures for a carbon steel (0.30% C - 1.5% Mn). The mechanical behavior of the steel was measured by torsion testing in the temperature range of 700 to 820 °C with holding times ranging from 1 to 30 min. The flow stress curves presented different shapes and stress levels. These differences were attributed to the ferrite and pearlite, ferrite and austenite, and austenite strained structures. When ferrite and pearlite were deformed together, the flow stress presented a hump with little straining; when the austenitic structure was deformed the shape of the flow stress curve was typical of materials having low stacking fault energy. The microstructural evolution observed by optical and scanning electron microscopy revealed that the evolution of the phase transformation was dependent on the testing temperatures, holding times and amount of straining. Comparisons were made on the kinetics of phase transformation with and without the application of plastic deformation, and evidence of strain-induced dynamic transformation was investigated.

Study of phase transformations In API 5L X80 Steel in order to increase its fracture toughness

Pedrosa,Igor Rafael Vilarouco; Castro,Renato Soares de; Yadava,Yogendra Prasad; Ferreira,Ricardo Artur Sanguinetti
Fonte: ABM, ABC, ABPol Publicador: ABM, ABC, ABPol
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/04/2013 EN
Relevância na Pesquisa
56%
Phase transformations in API 5L X80 steel were studied in different thermomechanical sequences with a view to increasing the fracture toughness of this steel. Dilatometry tests performed on the quenched steel detected a phase transformation occurred, during heating, in the temperature range 593-618 K. This phase transformation was identified as the dissolution of M-A islands. Based on preliminary dilatometric tests, ten thermal and thermomechanical treatments were performed on X80 steel samples. Initially, the material was hot rolled and quenched and only quenched. On the material without deformation, aging was also performed at temperatures of 603, 673, 723, 773, 823 and 873 K. These treatments resulted in the formation of the acicular ferrite constituent, among others. Tensile tests showed that the aging treatments produced reductions in yield strength and increases in the elongation and toughness of X80 steel. All the treatments resulted in an increase in the tensile strength of steel.

Effect of niobium in the phase transformation and corrosion resistance of one austenitic-ferritic stainless steel

Itman Filho,André; Silva,Rosana Vilarim; Cardoso,Wandercleiton da Silva; Casteletti,Luiz Carlos
Fonte: ABM, ABC, ABPol Publicador: ABM, ABC, ABPol
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/08/2014 EN
Relevância na Pesquisa
55.96%
Austenitic-ferritic stainless steels containing 0.2% and 0.5% niobium were evaluated with respect to the microstructures, microhardness, pitting potential resistance, electrochemical impedance and wearing tests. Niobium is an alphagenic element and has a great influence on phase transformation of duplex stainless steels. In the present investigation, the samples were annealed at 1050 ºC and aged at 850 ºC to promote the formation of sigma phase. The pitting potential resistance and electrochemical impedance were evaluated in 3.5 % sodium chloride solution. The wear coefficients were calculated by micro-wear tests conducted using a fixed ball machine and aluminum oxide as abrasive. The results show that the niobium content lead to increase on Laves phase formation. This phase, in association with the sigma phase, causes a significant increase in the hardness and wear resistance with a decrease on corrosion resistance of the austenitic-ferritic stainless steels.

Multiple phase silicon in submicrometer chips removed by diamond turning

Jasinevicius,R. G.; Porto,A. J. V.; Duduch,J. G.; Pizani,P. S.; Lanciotti Jr.,F.; Santos,F. J. dos
Fonte: Associação Brasileira de Engenharia e Ciências Mecânicas - ABCM Publicador: Associação Brasileira de Engenharia e Ciências Mecânicas - ABCM
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2005 EN
Relevância na Pesquisa
56%
Continuous chips removed by single point diamond turning of single crystal silicon have been investigated by means of Scanning Electron Microscopy/Transmission Electron Microscopy and micro-Raman Spectroscopy. Three different chip structures were probed with the use of electron diffraction pattern: (i) totally amorphous lamellar structure, (ii) amorphous structure with remnant crystalline material and, (iii) partially amorphous together with amorphous with remnant crystalline material. Furthermore, micro-Raman spectroscopy from the chips left in the cutting tool rake face showed different silicon phases. We have found, from a detailed analysis of the debris, five different structural phases of silicon in the same debris. It is proposed that material removal mechanisms may change along the cutting edge from shearing (yielding lamellar structures) to extrusion. Shearing results from structural changes related to phase transformation induced by pressure and shear deformation. Extrusion, yielding crystalline structures in the chips, may be attributed to a pressure drop (due to an increase in the contact area) from the tool tip towards the region of the cutting edge where brittle-to-ductile transition occurs. From this region upwards, pressure(stress) would be insufficient to trigger phase transformation and therefore amorphous phase would not form integrally along the chip width.

Application of Micro-Raman Spectroscopy to the Study of Yttria-Stabilized Tetragonal Zirconia Polycrystal (Y-TZP) Phase Transformation

Ramos, Carla MüeIler; Tabata, Américo Sheitiro; Cesar, Paulo Francisco; Rubo, José Henrique; Fracisconi, Paulo Afonso Silveira; Borges, Ana Flávia Sanches
Fonte: Soc Applied Spectroscopy Publicador: Soc Applied Spectroscopy
Tipo: Artigo de Revista Científica Formato: 810-814
ENG
Relevância na Pesquisa
65.98%
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Processo FAPESP: 2011/18061-0; The aim of this study was to perform micro-Raman spectroscopy as an alternative and nondestructive method to identify the phase transformation of zirconia after mechanical stress. The groups evaluated were experimental zirconia, zirconcad, IPS e.max ZirCad, and In Ceram YZ. Ten specimens were constructed for each group (n = 30) and subjected to a three-point bending test with a crosshead speed of 0.5 mm/min. The fractured surfaces were analyzed by micro-Raman spectroscopy. The laser power was kept at 10 mW, and scanning was performed in three regions of the fractured surface: (i) near the source of the failure (region of tensile stress), (ii) central to the fractured surface, and (iii) far from the source of failure. All materials showed the characteristic bands of tetragonal and monoclinic phases of zirconia. All zirconia studied showed a monoclinic phase in the tensile stress region. Micro-Raman spectroscopy was effective in detecting the presence of crystalline phases in polycrystals ceramics.

Texture Evolution and Variant Selection in Zr-2.5Nb During the α-β Phase Transformation

MOSBRUCKER, PAULA L.
Fonte: Quens University Publicador: Quens University
Tipo: Tese de Doutorado
EN; EN
Relevância na Pesquisa
56.09%
Zr-2.5Nb is used as the pressure tube material for 2nd and 3rd generation CANDU reactors. The physical properties of pressure tubes in service, including strength, dimensional stability, and delayed hydride cracking resistance, are largely dependent upon the crystallographic texture of the hcp α-phase, whose texture is predominantly developed during the extrusion stage of manufacturing. During extrusion and subsequent cooling, the formation of α may occur by transformation of the bcc β-phase to α according to the Burgers relationship and influenced by variant selection – that is, a preference for one or more of the twelve possible orientations of the hcp lattice relative to the bcc lattice. Variant selection has been observed in other Zr alloys, including the heat-treated zone in pressure tube welds and the bulk texture of heat-treated pressure tubes. Further, it has been proposed as a possible explanation for texture characteristics in pressure tubes that are not explained by the deformation mechanics of extrusion. However, the criteria for variant selection are unclear. In this work, an understanding of the criteria for variant selection is developed through observations of the differing mechanisms at play during both directions of transformation...

Age-hardenability and related microstructural changes during and after phase transformation in an Au-Ag-Cu-based dental alloy

Kim,Hyung-Il; Kim,Tae-Wan; Kim,Young-Oh; Cho,Su-Yeon; Lee,Gwang-Young; Kwon,Yong Hoon; Seol,Hyo-Joung
Fonte: ABM, ABC, ABPol Publicador: ABM, ABC, ABPol
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/02/2013 EN
Relevância na Pesquisa
56%
The aim of this study was to clarify how the microstructural changes during and after phase transformation determine the age-hardenability of an Au-Ag-Cu-based dental alloy. The rapid increase in hardness in the initial stage was the result of rapid atomic diffusion by spinodal decomposition into metastable Ag-rich' and Cu-rich' phases. The constant hardening after apparent initial hardening was the result of a subsequent transformation of the metastable Ag-rich' and Cu-rich' phases to the stable Ag-rich α1phase and AuCu I phase through the metastable AuCu I' phase. During the increase in hardness, fine block-like structure with high coherency formed in the grain interior, which changed to a fine cross-hatched structure. A relatively coarse lamellar structure composed of Ag-rich α1and AuCu I phases grew from the grain boundaries, initiating softening before the grain interior reached its maximum hardness. As a result, the spinodal decomposition attributed to rapid hardening by forming the fine block-like structure, and the subsequent ordering into AuCu I, which is a famous hardening mechanism, weakened its hardening effect by accelerating the lamellar-forming grain boundary reaction.

The effect of laser excitation on the Raman microspectroscopy of nanoindentation-induced silicon phase transformation

Mahon, Denise C; Mahon, Peter; Creagh, Dudley C
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
56.01%
It is well established that silicon undergoes a series of phase transformations when subjected to the pressure of nanoindentation. Phase transformations in silicon are studied using diamond anvil apparatus. The effect of the high pressure is an increase i

Nanoindentation-induced phase transformation in crystalline silicon and relaxed amorphous silicon

Rao, Rui; Bradby, Jodie; Ruffell, Simon; Williams, James
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
66.02%
Nanoindentation-induced phase transformation in both crystalline silicon (c-Si) and relaxed amorphous silicon (a-Si) have been studied. A series of nanoindentations were made with a sharp diamond Berkovich tip. During nanoindentations, maximum loads were