Metal-matrix composites spectroscopy

Colomban, R, Analysis of strain and stress in ceramic, polymer and metal matrix composites by Raman spectroscopy, Adv. Eng. Mater., 4, 535, 2002. 

Treatise on Materials Science and Technology. 1972-. (vols. 1-33, then unnumbered), San Diego, CA Academic Press. Each volume is an in-depth treatment of a topic, such as structural ceramics, metal matrix composites, and auger electron spectroscopy. 

Metal-ceramic interfaces are essential for the overall mechanical properties of ceramic (CMC) and metal matrix ceramic composites (MMC). The combined use of parallel electron energy loss spectroscopy (TEM/PEELS) and HREM imaging allows the direct determination of the arrangement of atoms along the interfaces from the Fe and/or Ni/Al20a composites processed by hot pressing [21]. 

A second method of studying vapor composition is to trap the atoms in a cold, inert material such as frozen argon or xenon. This can be done by employing liquid helium as a coolant (4 K) or special refrigeration units that can go down to below 20 K. A cold window can be employed inside a vacuum chamber, and the vapors coming off the hot metal source can be condensed on the cold window simultaneously with excess argon gas (atoms). In this way the metal particles can be surrounded and trapped in a frozen inert ice. Then the trapped atoms can be analyzed spectroscopically. This method is called matrix isolation spectroscopy and will be discussed in more detail in Section IL.B.2. 

The pure element standards can be also used as chemical composition standards. The certified properties are in this case the contents of all metallic traces at ultra trace level. BAM offers, e.g. BAM B Primary Cul with statements (certified values) of the content of 65 trace metal elements. This reference material is suitable for matrix matching in metal analysis, e.g. where using methods of atomic spectroscopy. 

Also the mode of adsorption (e.g. of CO, hydrocarbons, etc.) can depend on the available ensemble size or given composition of the surface [64—68]. It appears that the heat of adsorption of various modes of CO adsorption is only marginally influenced when the required ensemble (1,2 or 3 and more) is transferred from a pure metal into a matrix of another metal (for instance alloys with Cu, Au and Ag). When a CO molecule, monitored by IR spectroscopy, is taken as a probe of the local electronic structure of atoms (or ensembles of atoms), no pronounced effects of alloying are found 69-71]. 

In this review results from two surface science methods are presented. Electron Spectroscopy for Chemical Analysis (ESCA or XPS) is a widely used method for the study of organic and polymeric surfaces, metal corrosion and passivation studies and metallization of polymers (la). However, one major accent of our work has been the development of complementary ion beam methods for polymer surface analysis. Of the techniques deriving from ion beam interactions, Secondary Ion Mass Spectrometry (SIMS), used as a surface analytical method, has many advantages over electron spectroscopies. Such benefits include superior elemental sensitivity with a ppm to ppb detection limit, the ability to detect molecular secondary ions which are directly related to the molecular structure, surface compositional sensitivity due in part to the matrix sensitivity of secondary emission, and mass spectrometric isotopic sensitivity. The major difficulties which limit routine analysis with SIMS include sample damage due to sputtering, a poor understanding of the relationship between matrix dependent secondary emission and molecular surface composition, and difficulty in obtaining reproducible, accurate quantitative molecular information. Thus, we have worked to overcome the limitations for quantitation, and the present work will report the results of these studies. 

Inductively coupled argon plasma emission spectrophotometry (ASTM D-5708) has an advantage over atomic absorption spectrophotometry (ASTM D-4628, ASTM D-5863) because it can provide more complete elemental composition data than the atomic absorption method. Flame emission spectroscopy is often used successfully in conjunction with atomic absorption spectrophotometry (ASTM D-3605). X-ray fluorescence spectrophotometry (ASTM D-4927, ASTM D-6443) is also sometimes used, but matrix effects can be a problem. The method to be used for the determination of metallic constituents is often a matter of individual preference. 

Table 2 shows the chemical compositions of the porcelains measured by X-ray fluorescence spectroscopy (XRF 1500, Shimadzu), showing that all porcelains had aluminosilicate compositions with alkali and alkaline-earth metal oxides, besides other minor oxides. For porcelains containing leucite particles (C, D, and B), parts of Si02, AI2O3, and K2O contents composed these particles. Considering the fraction and stoichiometry of leucite (KAlSi206 = K20.Al203.4Si02), the compositions of glassy matrix of these porcelains were calculated and are also shown in Table 2. Note that all porcelains had in the glassy matrix an initial K2O content, and also potentially exchangeable Na ions by K ions from an external source.

In general, infrared spectroscopy can be used to investigate the chemical bonds of the NR matrix and the chemical links of the inorganic filled added to the matrix. For infrared spectrum of composites and nanocomposites based on NR, it is possible to identify all of the vibration band characteristics of the poly(cw-l,4-isoprene) structure being principally two main sets of bonds. The first set around 3000 cm and the second set around 1500 cm For the inorganic filler, it is expected to identify bands mainly between 800 and 200 cm that it can be attributed mainly to the metal-oxygen bonds. 

ABSTRACT. The paper details the use of scanning electron microscopy, surface reflectance infrared spectroscopy, Auger electron spectroscopy, ion scattering spectroscopy, secondary ion mass spectroscopy, and x-ray photoelectron spectroscopy in the analysis of polymeric adhesives and composites. A brief review of the principle of each surface analytical technique will be followed by application of the technique to interfacial adhesion with an emphasis on polymer/metal, fiber/matrix, and composite/composite adhesion. 

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