Crystallinity, thermal diffusivity, and electrical conductivity of carbon black filled polyamide 46

Polyamide 46 (PA 46) with carbon black (CB) has been subjected to a heat treatment. Crystallinity, specific heat capacity, crystalline melting peak temperature, thermal diffusivity, and electrical conductivity were measured. The crystallinity increases with duration of thermal treatment. The maximum value is dependent on the filler fraction. A lower CB content leads to a higher crystallinity at maximum tempering time. The crystalline melting peak temperature increases with decreasing filler fraction and duration of thermal treatment due to different crystal types and/or diverging geometric forms of the crystals. Thermal diffusivity and electrical conductivity act positively proportional to each other and increase with CB content and tempering time. The thermal diffusivity decreases with increasing temperature. The volume resistance of PA 46 is lowered by heat treatment. By CB addition in combination with a tempering process, the PA 46 can be transferred into a conductor. CB is moved by PA 46 crystals into amorphous regions forming conductive pathways

Damping of the woodwind instrument reed material Arundo donax L

The viscoelastic properties (E', G', tanΦ, δ) of Arundo donax (AD) and a polypropylene-beech fiber composite (PPC) were measured from RT to 580K for various frequencies and strains. E' of AD varies between 5250-6250MPa depending on ageing at RT while E'(RT)=2250MPa of PPC is signifcantly lower. E' of the AD is higher than E' of PPC in the whole investigated temperature range with the exception of AD after a heat treatment up to 575K. Damping spectra exhibit peaks around 340K (Q=234kJ/mol) and 415K for the PPC related to relaxations in the crystalline part of polypropylene and the relaxation at melting temperature. For AD damping peaks were found at 350K (Q=320kJ/mol) related to the glass-rubber transition of lignin, at 420K due to a reorganization in the amorphous phase of lignin, at 480K related to micro-Brownian motions in the non-crystalline region of cell-wall polymers and reduction of the crystallinity of cellulose, and at 570K due to the polymeric compounds of wood and/or a decomposition of lignin. The course of E' and tanΦ of AD and PPC is comparable from 20-200Hz, whereas tanΦ of AD is lower than tanΦ of PPC while E' of AD is higher than E' of PPC.Fil: Weidenfeller, Bernd. Technische Universitat Clausthal; AlemaniaFil: Lambri, Osvaldo Agustin F.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario; Argentina. Universidad Nacional de Rosario. Facultad de Ciencias Exactas, Ingeniería y Agrimensura; ArgentinaFil: Bonifacich, Federico Guillermo. Universidad Nacional de Rosario. Facultad de Ciencias Exactas, Ingeniería y Agrimensura; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario; ArgentinaFil: Arlic, Uwe. Technische Universitat Clausthal; AlemaniaFil: Gargicevich, Damian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario; Argentina. Universidad Nacional de Rosario. Facultad de Ciencias Exactas, Ingeniería y Agrimensura; Argentin

Damping of Fe-Al Alloy Electrodeposited in an Ionic Liquid

Iron-Aluminium alloys were produced by the electro-deposition of iron-aluminium on a copper substrate. The electro-deposition process was done in the ionic liquid 1-butyl-1-methylpyrrolidinium trifluoromethylsulfonate, [Py1,4]TfO. A solution of (0.2 M FeCl2 + 2.75 M AlCl3)/ [Py1,4] TfO was used at a temperature of T=363 K because this mixture is solid at room temperature. Electrodeposited samples were studied by means of mechanical spectroscopy, differential thermal analysis and laser light microscopy. Mechanical spectroscopy studies were performed as a function of temperature, frequency and strain. The usual damping peaks for copper, low temperature grain boundary peak, recovery peak and intermediate temperature grain boundary peak were observed. In addition, a new damping peak at around 800 K which is not thermally activated was discovered. The physical mechanism controlling the appearance of this new peak is the dissolution of small precipitates or agglomerates of defects which take place at around 800 K during the warming and the subsequent re-precipitation/re-agglomeration during the cooling. This process could occur either in the copper substrate or at the Fe-Al electrodeposit.Fil: Lambri, Osvaldo Agustin F.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario; Argentina. Universidad Nacional de Rosario. Facultad de Ciencias Exactas Ingeniería y Agrimensura. Escuela de Ingeniería Eléctrica. Laboratorio de Extensión e Investigación en Materiales; ArgentinaFil: Weidenfeller, Bernd. Technische Universitat Clausthal; AlemaniaFil: Bonifacich, Federico Guillermo. Universidad Nacional de Rosario. Facultad de Ciencias Exactas Ingeniería y Agrimensura. Escuela de Ingeniería Eléctrica. Laboratorio de Extensión e Investigación en Materiales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario; ArgentinaFil: Pulletikurthi, Giridar. Technische Universitat Clausthal; AlemaniaFil: Xu, Jiayi. Technische Universitat Clausthal; AlemaniaFil: Weidenfeller, Laura. Technische Universitat Clausthal; Alemani

Simulation of thermally induced stresses in glass-polymer composites

Due to differenees in thermal expansion, crazing and delamination effects are observed in multiphase materials such as glasspolymer composites. For a composite consisting of spherical particles homogeneously embedded in a matrix phase, the radial and tangential stresses occurring have been simulated. Two-dimensional calculations were used as a basis for optimizing the optical transparency of the material which was found to be strongly affected by the mechanical properties of the constituents of the composite and the resulting stresses. Further, the influence of the shape and the size distribution of the particles on the emergence of scattering surfaces inside the material is described. With the Christiansen-Shelyubskii method the maximum transparency of a potential material depending on whether it is a gradient material or not can be predicted

Electrodeposition of Al from a 1-butylpyrrolidine-AlCl3 ionic liquid

The addition of 1-butylpyrrolidine to AlCl3 results in the formation of an electrolyte that is suited to Al deposition. The feasibility of electrodepositing Al from the synthesized electrolyte was investigated. Several compositions of AlCl3 and 1-butylpyrrolidine were prepared for this purpose. These mixtures show a different phase behavior at various compositions of AlCl3 and 1-butylpyrrolidine. IR, Raman and NMR spectroscopy were employed to characterize the synthesized liquids. Among the prepared compositions, 1:1.2 mol ratio of 1-butylpyrrolidine:AlCl3 and the upper phase of 1:1.3 mol ratio of 1-butylpyrrolidine:AlCl3 were found to be suitable for Al electrodeposition at room temperature (RT). Uniform and thick (~µm thick) layers of Al were obtained on copper at RT. Al deposition occured from the cationic species of AlCl3−xLy+ (where x≤2, y=1–2, and L=1-butylpyrrolidine) in this electrolyte. This behavior is contrary to the well investigated classic AlCl3 based ionic liquids, where the deposition of Al occurs mainly from anionic Al2Cl7− ions

Determination of materials and methods used in the manufacture of a Weltklang saxophone made in East Germany in 1960 by means of archaeometric techniques

El presente trabajo muestra un estudio de caracterización mediante técnicas arqueométricas, de los materiales utilizados para la fabricación de un saxofón “Weltklang” proveniente de la, por entonces, República Democrática Alemana. Para tal fin se implementaron estudios de fluorescencia de rayos X, microscopía óptica, microscopía electrónica de barrido con análisis dispersivo de energías y termogravimetría. El saxofón fue fabricado en 1960, siendo parte de la línea de saxofones Weltklang (B&S) con el número de serie 32936, y permaneció en uso hasta el año 2002. Los resultados mostraron que el material base del ejemplar era el bronce, con una composición (Cu- 28% masa Zn); la cual se ajusta a las composiciones actuales para los bronces a nivel internacional. Con respecto al plateado observable en la superficie del instrumento, los análisis realizados permitieron determinar que éste se obtuvo probablemente mediante inmersión en un baño compuesto de cianuro de plata, cianuro de potasio y carbonato de potasio; pudiéndose determinar en consecuencia no sólo el método implementado sino también la composición del compuesto utilizado para dicho tratamiento. A su vez, se encontraron diferentes tipos de imperfecciones en las muestras que corresponden principalmente al lado interior del instrumento, lo que indica la existencia de zonas falladas en el proceso de bañado, las cuales probablemente fueron reparadas por fundición local de plata sobre esas mismas áreas defectuosas. Los datos obtenidos en este estudio muestran la potencialidad del uso de técnicas arqueométricas para poder inferir los métodos utilizados para la fabricación de instrumentos musicales antiguos, y, por consiguiente, la viabilidad de la arqueometría para la reconstrucción de modos de elaboración de aquellos instrumentos musicales que puedan recuperarse en contextos arqueológicos. Al mismo tiempo, los resultados provenientes de los análisis implementados en este trabajo demuestran la aplicabilidad de la arqueometría para casos de estudios relacionados con la arqueometalurgia histórica y la arqueología industrial.The present work shows a characterization study by means of archaeometric techniques of the materials used for the manufacture of a “Weltklang” saxophone from the formerly German Democratic Republic. For fulfill this purpose, X-ray fluorescence, optical microscopy, scanning electron microscopy with dispersive energy analysis and thermogravimetry studies, were implemented. The saxophone was manufactured in 1960, being part of the Weltklang (B&S) line of saxophones with serial number 32936, and remained in use until 2002. The results showed that the base material of the sample was brass, with a composition (Cu- 28% mass Zn); which conforms to current compositions for brasses internationally. Regarding the silver layer observable on the surface of the instrument, the analyzes allowed to determine that it was probably promoted by the immersion of the instrument in a plating bath composed of silver cyanide, potassium cyanide and potassium carbonate. Therefore, the implemented method for plating the instrument and also the components of the used bath were determined. In turn, different types of imperfections were found in the samples that correspond mainly to the inner side of the instrument, which indicate the existence of faulty areas of the bathing process. These areas were probably repaired by the local deposition of melted silver above those faulty areas. The data obtained in this study show the potentiality of the use of archeometric techniques to infer the methods used in the manufacture of ancient musical instruments. Consequently, the viability of archaeometry for the reconstruction of the elaboration procedures of those musical instruments which can be recovered in archaeological contexts has been shown.Fil: Lambri, Melania Lucila. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario; Argentina. Universidad Nacional de Rosario. Facultad de Ciencias Exactas Ingeniería y Agrimensura. Escuela de Ingeniería Eléctrica. Laboratorio de Extensión e Investigación en Materiales; Argentina. Universidad Nacional de Rosario. Facultad de Humanidades y Artes. Escuela de Antropología. Centro de Estudios de Arqueología Historica; ArgentinaFil: Weidenfeller, Laura. Ilmenau University of Technology; AlemaniaFil: Lambri, Osvaldo Agustin F.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario; Argentina. Universidad Nacional de Rosario. Facultad de Ciencias Exactas Ingeniería y Agrimensura. Escuela de Ingeniería Eléctrica. Laboratorio de Extensión e Investigación en Materiales; Argentina. Universidad Nacional de Rosario. Facultad de Humanidades y Artes. Escuela de Antropología. Centro de Estudios de Arqueología Historica; ArgentinaFil: Weidenfeller, Bernd. Clausthal University of Technology; AlemaniaFil: Bonifacich, Federico Guillermo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario; Argentina. Universidad Nacional de Rosario. Facultad de Ciencias Exactas Ingeniería y Agrimensura. Escuela de Ingeniería Eléctrica. Laboratorio de Extensión e Investigación en Materiales; Argentina. Universidad Nacional de Rosario. Facultad de Humanidades y Artes. Escuela de Antropología. Centro de Estudios de Arqueología Historica; ArgentinaFil: Zelada, Griselda Irene. Universidad Nacional de Rosario. Facultad de Ciencias Exactas Ingeniería y Agrimensura. Escuela de Ingeniería Eléctrica. Laboratorio de Extensión e Investigación en Materiales; Argentina. Universidad Nacional de Rosario. Facultad de Humanidades y Artes. Escuela de Antropología. Centro de Estudios de Arqueología Historica; ArgentinaFil: Rocchietti, Ana Maria. Universidad Nacional de Rosario. Facultad de Humanidades y Artes. Escuela de Antropología. Centro de Estudios de Arqueología Historica; Argentin

Impact of Alloy Composition and Thermal Stabilization on Martensitic Phase Transformation Structures in CuAlMn Shape Memory Alloys

<div><p>Alloys of CuAlMn are known as cheap, high strength shape memory alloys with an excellent damping capacity within their austenitic-martensitic phase transformation, compared to alloy systems like NiTi, CuZnAl or MnCu. But CuAlMn alloys have disadvantage due to generation of voids by a high shrinkage which further increases the existing proneness to stress cracks during rapid cooling. Alloying grain refining elements improves the stress crack resistance and enables a wide range of rapid quenching parameters which are needed to control the temperature of martensitic phase transformation. Additionally, the elements itself influence the in- or decreasing of the phase transformation temperature and the SMA effects. Furthermore, some of these elements can reduce the internal friction indirectly by decomposing areas of metastable martensite into its stabilized forms, where no transformation occurs. This thermic stability can be calculated by the concentration of valence electrons in a unit cell. The proneness to ageing is controlled by multistep heat treatments. Annealing and rapid quenching into the area of martensitic phase transformation maximize the generation of point defects. A high amount of point defects contradicts the negative effect of pinning. It also preserves the material from extreme brittleness. The influences of these effects are shown at single cantilever bending beams by elastic strain amplitude (ε = 12E-4) depending measurements of internal friction at natural frequency along the ageing at room temperature (293 K) up to 2500 h. The samples are annealed at 1123 K for 15 min (CuAl14Mn2) and 1100K for 30min (CuAl11Mn5) afterwards rapid quenched to 370 K with no further thermic stabilisation. The base alloy of CuAl14.1Mn2.0Ni1.9Fe0.4 had an internal friction measured as logarithmic Decrement (δ) of 0.155 and 0.11 after 2500 h of ageing at RT. The phase transformation is located between 284 K and 352 K, measured by DSC. The alloy of CuAl11.1Mn5.5Zn2.9Ni2.1 had a logarithmic decrement of 0.31 and diminish continuously to 0.12 after 2500 h of ageing at RT. The phase transformation is located between 287 K and 318 K.</p></div

Recognizing boiled bone-remains from the Boca de Lega archaeological site in Argentina through mechanical spectroscopy studies

A study in thermo-altered bone-remains recovered from the Boca de Lega archaeological site (Santa Fe, Argentina) is performed with the aim of distinguishing among the whole group of seven investigated bone-remains which ones were boiled during culinary activities. In fact, for the boiled-bone-remains, the damping spectra exhibited the appearance of the damping peaks related to the loss of free water, the loss of the crystallization water, and the peak related to the viscous movement of collagen fibrils, after the triple helix to random coil transition; at around 370 K, 420 K and 510 K, respectively. In addition, the dynamic modulus behaviour in boiled samples exhibited the peaked shape behaviour as a function of temperature, i.e., an increase from around 370 K up to around 450 K, which was already reported for experimental bones. The results from mechanical spectroscopy were corroborated through scanning electron microscopy studies at high resolution. Besides, differential thermal analysis, thermogravimetry, and energy dispersive spectroscopy, are used also as instrumental techniques and their obtained results are discussed in the present work too.Fil: Lambri, Melania Lucila. Universidad Nacional de Rosario. Facultad de Ciencias Exactas Ingeniería y Agrimensura. Escuela de Ingeniería Eléctrica. Laboratorio de Extensión e Investigación en Materiales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario; ArgentinaFil: Lambri, Osvaldo Agustin F.. Universidad Nacional de Rosario. Facultad de Ciencias Exactas Ingeniería y Agrimensura. Escuela de Ingeniería Eléctrica. Laboratorio de Extensión e Investigación en Materiales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario; ArgentinaFil: Weidenfeller, Martin. No especifíca;Fil: Bozzano, Patricia Beatriz. Universidad Nacional de San Martín. Instituto Sabato; ArgentinaFil: Bonifacich, Federico Guillermo. Universidad Nacional de Rosario. Facultad de Ciencias Exactas Ingeniería y Agrimensura. Escuela de Ingeniería Eléctrica. Laboratorio de Extensión e Investigación en Materiales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario; ArgentinaFil: Weidenfeller, Bernd. No especifíca;Fil: Lambri, Fernando Daniel. Universidad Nacional de Rosario. Facultad de Ciencias Exactas Ingeniería y Agrimensura. Escuela de Ingeniería Eléctrica. Laboratorio de Extensión e Investigación en Materiales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario; ArgentinaFil: Zelada, Griselda Irene. Universidad Nacional de Rosario. Facultad de Ciencias Exactas Ingeniería y Agrimensura. Escuela de Ingeniería Eléctrica. Laboratorio de Extensión e Investigación en Materiales; ArgentinaFil: Rocchietti, Ana Maria. Universidad Nacional de Rosario; Argentina. Universidad Nacional de Río Cuarto; Argentin