Microstructural Details (microstructural + detail)

Distribution by Scientific Domains


Selected Abstracts


Monotonic and Cyclic Deformation Behaviour of the SiC Particle-Reinforced Aluminium Matrix Composite AMC225xe,

ADVANCED ENGINEERING MATERIALS, Issue 4 2010
Marek Smaga
The monotonic and cyclic deformation behaviour of the aluminium matrix composite AMC225xe , i.e., the aerospace grade aluminium alloy AA 2124 reinforced with 25,vol.-% ultrafine SiC particles , is characterised in detail on the basis of mechanical stress,strain hysteresis curves as well as temperature and electrical resistance measurements. A pronounced difference in plastic strain response is observed between tension and compression under monotonic and cyclic loading. In fully reversed stress-controlled constant amplitude tests, negative plastic mean strains developed. The cyclic deformation behaviour of AMC225xe is characterised by pronounced initial cyclic hardening. The endurance limit is reliably estimated in continuous load increase tests. In particular, electrical resistance data are used as input parameters for fatigue life calculations analogous to the Basquin equation. Microstructural details are investigated by light and scanning electron microscopy. [source]


New Record of Palaeoscolecids from the Early Cambrian of Yunnan, China

ACTA GEOLOGICA SINICA (ENGLISH EDITION), Issue 2 2008
HU Shixue
Abstract: A new palaeoscolecid, Guanduscolex minor Hu, Luo et Fu gen. et sp. nov., with preserved soft parts of introvert and intestines comes from the Lower Cambrian Guanshan fauna of Yunnan, South China. Microstructural details of the cuticle revealed by scanning electron microscopy (SEM) show that each annulation bears three rows of plates and each plate bears 9,10 marginal and 4,5 central nodes. This discovery sheds new light on the relationships and evolutionary pathway of the palaeoscolecids and other early priapulids. [source]


m/p -Cresol,based t -BOC protected alternating "high ortho" copolymer as a possible e-beam resist: Characterization using multidimensional NMR spectroscopy,

JOURNAL OF APPLIED POLYMER SCIENCE, Issue 4 2009
Maneesh Sharma
Abstract Synthesis of a m/p -cresol,based novolac resin and its subsequent esterification using di- tert -butyl dicarbonate (t -BOC) is described. The product has been characterized using techniques of FTIR spectroscopy, one dimensional 1H NMR, 13C NMR, and DEPT-135 spectra. Two dimensional NMR experiments like, COSY, HSQC, and HMBC have been used for exhaustive probing of the microstructural details of the derivatized copolymer. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 [source]


Correlating Raman peak shifts with phase transformation and defect densities: a comprehensive TEM and Raman study on silicon

JOURNAL OF RAMAN SPECTROSCOPY, Issue 6 2009
Thomas Wermelinger
Abstract Silicon is the most often used material in micro electromechanical systems (MEMS). Detailed understanding of its mechanical properties as well as the microstructure is crucial for the reliability of MEMS devices. In this paper, we investigate the microstructure changes upon indentation of single crystalline (100) oriented silicon by transmission electron microscopy (TEM) and Raman microscopy. TEM cross sections were prepared by focused ion beam (FIB) at the location of the indent. Raman microscopy and TEM revealed the occurrence of phase transformations and residual stresses upon deformation. Raman microscopy was also used directly on the cross-sectional TEM lamella and thus microstructural details could be correlated to peak shape and peak position. The results show, however, that due to the implanted Ga+ ions in the lamella the silicon Raman peak is shifted significantly to lower wavenumbers. This hinders a quantitative analysis of residual stresses in the lamella. Furthermore, Raman microscopy also possesses the ability to map deformation structures with a lateral resolution in the submicron range. Copyright © 2009 John Wiley & Sons, Ltd. [source]