The refraction effect at small incidence angles was investigated for solid Al2O3 disks of varying surface roughness, and Al2O3 and LaB6 powder layers of varying thickness and roughness using pseudo parallel beam optics. For the disks the peak shift Δ2θ correlated approximately inversely with ζmax, the maximum slope of a sinusoidal model of the surface roughness. For a disk polished with 3θm diamond, Δ2θ exceeded that predicted by the James equation. For the powder layers Δ2θ was very small for the thinnest layers. For thicker, rougher layers Δ2θ was larger and was probably due to displacement error from the 0.4° divergence of the Soller slit used and specular reflection of the diffracted beam from the Soller slit leaves.

The internal stress state in a Al2O3-SiC composite has been studied with X-ray diffraction and with calculations with a modified Eshelby model. The influence (on the internal stress state) of volume fraction, temperature, geometric shape, and the orientation of the silicon carbide particles are discussed. The stress tensors were measured in both the matrix and in the reinforcing phase, and the macro- and microstresses were separated for ail the components. Good agreement with the microstresses for the Eshelby model is found in all cases.

Results from X-ray diffraction experiments at low temperature (45-295 K) on the coefficient of thermal expansion are also presented.

The changes in micro structure and hardness of massively transformed Ti-48mol%Al alloys with tempering were investigated. The results were correlated to the X-ray profile analysis. The integral width of Cu-kα1 net peak especially from γ (111) plane related well to the hardness change. Hall plots suggested that lattice strains are released by spheroidizing with the recovery at low temperature and then small particles grow at higher temperatures, as might support the microstructural change. The small particle size is therefore presumed to be the controlling factor for the hardness. Macro stress is shown not to affect the hardness as much.

The properties of the surface on various machine parts are very important. We are required to improve wear resistance, fatigue strength and thermal properties of the surface. Recently, ceramic films coated on various parts were widely used in industry, where they were improved the properties of the surface. Diamond is a new coating film deposited by the CVD method giving a film which is very hard and excels in wear resistance. In the past few years, a diamond film deposited by CVD method has become available for use in industry, however, the properties of the film remain unknown, and it is important to determine these properties.

An x-ray diffraction (sin2ψ) method has been successfully used to measure the oxidation stresses at room temperature in annealed and electropolished samples of polycrystalline Cu coupons of different thickness’ (0.75, 1.25, and 2.25 mm thick) oxidized for 15 and 30 minutes at temperatures 700, 800, and 900° C, Oxide scale stresses are generally a result of both differential Coefficient of Thermal Expansion (CTE) and the Pilling-Bedworth Ratio (PBR). At the oxidation temperatures of this study, the oxide scale consisted of a mixture of both CuO and Cu2O. Residual stress measurements were made in the Cu2O phase. In this system, the average stresses on the free surface of the oxide (<σ11> and <σ22>) were compressive and the average stress through the thickness (<σ22>) normal to the oxide layer was found to be tensile.

Residual stress in thin films of RF-sputtered aluminum coated on substrate of glass was measured by X-ray multiaxial stress measurement. The films were manufactured under the various conditions such as temperature of substrate ranged from 473K to 573K, and pressure of argon gas range from 0.0093Pato 13.3Pa respectively. These results brought comprehension that residual stress existed in tri-axial and that was influenced by temperature of substrate and pressure of argon gas. Residual stresses were unstable in range of less than 1.33Pa of pressure of argon gas.

In this work we apply high-resolution X-ray diffractometry to the study of InGaAs/GaAs multiple quantum well structures on (001) and(lll)B GaAs substrates. The samples consisted of p-i-n diodes with a multiple quantum well embedded in the i-region and were simultaneously grown on (001) and (111)B substrates by molecular beam epitaxy. For the characterization we have used symmetric and asymmetric reflections at different azimuthal positions. The interpretation of the diffraction profiles has been possible thanks to our recently developed simulation model, which allows the calculation of any reflection regardless of the substrate orientation. X-ray results about composition and thickness are very similar in the samples simultaneously grown on both orientations as expected from our specific growth conditions. The information obtained from X-ray characterization is consistent with the results of photoluminescence and photocurrent measurements within the experimental uncertainty of the techniques. In (lll)B samples, X-ray diffractometry provides structural information which cannot be easily obtained from optical characterization techniques.

Accurate measurement of the lattice misfit between the γ and γ phases in Ni-base single crystal superalloys at high temperatures has successfully been achieved using a parallel beam mode X-ray diffractometer with a high temperature specimen stage. The superalloys have γ' precipitates, an ordered FCC structure based on Ni3Al, in a γ-matrix having a disordered FCC structure (LI2). The parallel beam mode, the optics of which is made from a Ge (111) channel cut crystal, generates a superior monochromatic and parallel CuKα1 beam, which makes it possible to resolve a cluster peak in Ni-base superalloys into individual γ and γ ‘ peaks. This peak separation was almost impossible using the CuKα1+2 doublet beam from the standard type para-focusing mode, due to the very small difference in lattice parameters between the two phases.

Program “Breadth” was written for analyzing diffraction-line broadening. The physically broadened line profiles are required as input. The results are calculated according to three ”simplified” integral-breadth methods: Cauchy-Cauchy, Cauchy-Gauss, and Gauss-Gauss. The program output includes volume-weighted coherent domain size and a maximum strain. Furthermore, the root-mean-square strain and both surface-weighted and volume-weighted domain sizes are calculated according to the “double-Voigt” method. This method also allows the accurate determination of both surface-weighted and volume-weighted domain-size distribution functions for specimens showing a dominant size-broadening effect, which gives more detailed information than the mere average value of coherent-domain size. Some examples for ball-milled W (shows simultaneous size-strain broadening) and NiFe2O4 (shows pronounced pure-size broadening) are included.

The composition of the sample related-effects with those from the instrument, has been carried out by convolution of involved terms. The sample-related effects have been modelled via the modulation function accounting for packed parallel planes, named here “layers”, and other structure-related parameters. The instrumental parameters have been determined using DISVAR93, a softawre package allowing the diffraction profiles to be represented in the more convenient shape of a pseudo-Voigt function. A constrained optimization process is the basis for determining these instrumental parameters; their calibration is typically carried out by adopting an external standard sample. The comparison of the modeled intensity distribution with the experimental one is performed via minimization of χ2 where the convolutor and minimizator are embedded engines of the algorithm.

The measurement of retained austenite is important in the analysis and quality control of asmanufactured steel components, as well as to the evaluation of components returned from service. The amounts of retained austenite are most accurately measured using x-ray diffraction techniques where the integrated area under the austenite and martensite diffraction peaks from a sample are determined. In addition to quantitative information about the amount of each phase, however, the raw x-ray diffraction data contains other information that may be useful in evaluating the condition of a steel component. The diffracting particle size of both the martensite and austenite phases, and the presence and degree of preferred orientation in both phases can be calculated from the basic four peak retained austenite x-ray scan. This information, in conjunction with knowledge of the amount of retained austenite present, may be used to determine information about variations in materials and manufacturing processes as well as changes due to service. If the residual stress in both phases is also measured, additional conclusions can be made regarding changes due to processing and service. The theoretical and experimental aspects of these measurements are reviewed data from a case history in which these types of measurements were used to determine changes due to processing and service are presented.

Austenitic stainless steel has large toughness and high corrosion resistance compared to other alloy steels. The austenite near the fracture surface will be transformed to the martensite when it is fractured. In the present study, X-ray fractography is applied to a fatigue fracture surface of austenitic stainless steel. The fatigue tests were carried out on compact tension ( CT ) type specimens. The volume fraction of transformed martensite was quantitatively evaluated on fatigue fracture surfaces by the X-ray method. The plastic strain on the fracture surface was estimated by measuring the line broadening of X-ray diffraction profiles. The size of plastic zone left on the fatigue fracture surface was determined from the distribution of the line broadening

X-ray diffraction observation of fracture surfaces provides fracture analysis with useful information on the mechanisms and mechanical conditions of fracturing. This method is called ” X-ray fractography “ and has been developed especially in Japan as a new engineering tool for fracture analysis.

In the present paper, X-ray fractography is applied to fatigue fracture surfaces of AZ91 magnesium alloy which are used for machine parts. The X-ray stress constant, H,was first determined. The fatigue tests were conducted by using compact tension ( CT ) specimens of AZ91 magnesium alloy. The residual stress was measured on and beneath the fatigue fracture surface. The depth of the plastic zone left on the fatigue fracture surface was evaluated from the residual stress distribution. The results are discussed on the basis of fracture mechanics.

The objective of this study was to measure the peak broadening inherent in chi (x) tilting and compare that to a geometrical model. The (012) and (300) reflections from a Al2O3 plate (NIST SRM 1976) were each scanned every 100 from -700 to +700x (15 lilts/reflection) to examine the influence of a low and high 2θ, respectively. The absorption correction was not taken into account. The equation y=2m1| tan x | cosθ+m2 fits well the data from both low and high 2θ except the point x =0. The extended equation y=m1cosh(m2tan x cosθ) fits well with all the experimental points.

X-ray diffraction (XRD) scans of many semicrystalline polymers, in which noncrystalline (amorphous) phases with varying degrees of order coexist with more than one crystalline phases, are usually not well resolved. Resolution of such data can be enhanced by deconvolving the effect of size broadening using maximum entropy methods. The use of resolution-enhanced XRD scans for studying the order in the noncrystalline (amorphous) domains and for studying small differences in the crystalline regions in poorly crystallized polymers is illustrated with examples from polyamides and polyesters. Crystallinity in poorly crystallized polymers is determined using an amorphous template obtained by analyzing highly crystalline polymers. The degree of order in the noncrystalline regions is evaluated from the changes in the shape and the position of the amorphous scattering. It is suggested that these procedures can be a part of the documentation of laboratory procedures required for ISO (International Organization for Standards) certification.

A full structure analysis of a completely crystallized sample of high-density polyethylene (HDPE) has been achieved using x-ray powder diffraction data collected on a laboratory-based powder diffractometer. The structure refinement is performed using the Rietveld method and includes refinement of the carbon and hydrogen atomic positions and temperature factors. The C-C and C-H bond distances and the C-C-C bond angle along the polyethylene chain have been calculated from the refined atomic positions and are in very good agreement with previous experimental and modelling determinations. Evaluations of the pseudo-Voigt profile parameters for Lorentzian strain broadening and me Scherrer coefficient for Gaussian broadening yield reasonable values for microstrain and particle size for this sample. Refinement of the preferred orientation parameter indicates that the HDPE flakes consist of platy crystals or lamellae that are packed normal to the diffraction vector.

We have developed a novel method of determining polymer fiber morphology. Analysis of pair-density functions obtained from synchrotron x-ray diffraction patterns with scattering vectors lying in the meridional direction and equatorial plane allows for the determination of crystallite dimensions, volume fractions of crystalline and amorphous phases, and the probability distribution of crystallite c axis orientation relative to the fiber axis. This method is independent of details regarding the structure of the amorphous phase, and may be successfully applied to both highly crystalline and poorly crystalline samples. Here we describe this new polymer fiber morphological analysis technique, and present examples of its application to three NOMEX aramid samples of widely differing morphologies.

Crystallographic data for a wide range of crystalline borates are used as a basis to propose a set of topological criteria for the formation of vitreous borate networks, taking into account the topological degrees of freedom necessary for conventional glass formation. It is shown that considerable insight into the structural criteria for the formation of borate networks can be gained by studying the arrangements of superstructural units found in the various crystalline borates.

The aromaticity fa, crystallite parameters dm, dy, La, Lc, Mc, and RDF parameters r1 and Ka have been determined for sedimentary organic matter, such as kerogens, coals, and bitumens. Here, the rt value is the interatomic distance between the nearest neighbors of carbon atoms, and Ka is an empirical coefficient as an indicator of the degree of order-stacking for aromatic clusters. The refined methods of X-ray diffraction include the improved experimental conditions and new computer programs. The computer programs are composed of four software: AMORPHOUS software; NORMALIZATION software; RDF (Radial Distribution Function) software; and MPS (Multiple Peak Separation) software.

Coal mine dust is produced from complex materials which consist of organic sedimentary phases, inorganic minerals, and trace elements. The dust varies in its chemical compositions and is capable of causing lung injury when inhaled. The purpose of this study was to perform scanning electron microscopy combined with energy dispersive spectrometry, wavelength dispersive spectrometry and X-ray diffraction analyses of three coal dusts and examine their effects on rat lung alveolar macrophages (AM) in cell culture. The coal dusts were obtained from coal surfaces of anthracite, meager and fat coal mines. AM were harvested by bronchoalveolar lavage from adult male Wistar rats and were cultured in Eagle's medium at 37°C.