Diffraction Peak Width Research Articles

On some distinct characteristics of reactive and normal flash sintering: A case study using low-temperature synthesized p-type cuprous delafossite, CuCrO2

We report the rapid synthesis of the high temperature cuprous delafossite (CuCrO2) through a single-step Reactive Flash (RF) method at furnace temperature, Tf=270 ℃ and dc electric field, E≈160 V/cm in ≈ 6.5 min from mixed oxides of Cu and Cr. Besides successful synthesis, we also investigate the larger question of the effect of external dc fields and current on nucleation and growth (N-G) type systems with accompanying compositional changes, typical of chemical reactions. CuCrO2 powders obtained from a hydrothermal route with an abundance of product nuclei were used to investigate the effect on N-G systems with insignificant compositional change (fine-grained/amorphous → coarse-grained). Temperature dependent current measurements towards the end of stage I indicate processes with activation energies of ∼3 eV, suggesting incipient electrochemical and ionic activity. In both scenarios (nucleation, growth, and chemical reactions), the influence of the E-field (Stage I) is far surpassed by the electric current (Stage III) yielding almost single-phase microstructures and p-type conductivity with [h] ≈1014/cm3. Subtle distinctions are identified in the flash characteristics using descriptors including widths of diffraction peaks and average voltage fluctuations.

Elucidating a proper framework for the determination of threading dislocation densities in semiconductor films: a comprehensive study based on Ge/Si(001)

Abstract Methods of deducing threading dislocation densities (TDDs) from x-ray diffraction (XRD) peak widths have been reevaluated based on crystallography theories. Moreover, Ge/Si heteroepitaxial structures were taken as model materials for investigation. The procedure is tailored in accordance with the specific designs of modern XRD systems to minimize instrumental interference, whereas practical characteristics of heteroepitaxial films are also considered to avoid intrinsic errors. TDDs of samples grown with different epitaxy methods were investigated using the newly implemented XRD method and etch pit density (EPD) method, and satisfactory agreement has been achieved among three independently calculated sets of TDD results: two from XRD and one from EPD. These values were further corroborated by cross-sectional transmission electron microscopy analysis. Key considerations that are of scientific and technical importance in TDD studies are also discussed in detail. The present work provides not only the most up-to-date elucidation on obtaining TDD values in semiconductor epitaxial films, but also insights into the long-existing ambiguity in TDD calculation methods, which will be helpful for the future studies of defect density characterizations in various material systems.

An approach for identifying the deformation-induced strain from tensile tests and x-ray diffraction measurements

ABSTRACT Non-uniform plastic deformation and phase transformation introduce residual stress (RS) in a material. The present study focuses on the influence of tensile strain on RS development in 304L austenitic stainless steel, wherein strain-induced martensite (SIM) transformation influences deformation behaviour. Room temperature tensile tests were interrupted at various tensile strains between the material yield and ultimate tensile strength at 5.21 × 10−4 and 1.3 × 10−2 s−1 strain rates. Microstructural characterisation of as-received and deformed samples by electron backscatter diffraction provides evidence of SIM formation and shear bands. Analysis of tensile flow and work hardening behaviour is discussed in correlation to the microstructural and dislocation density variations. In addition, RS in the austenite and martensite phases was measured using the x-ray diffraction method, and the RS balance that occurs between the longitudinal and transverse components and the two phases after tensile deformation is presented. It is shown that a combined analysis of RS and x-ray diffraction peak width could be utilised to find the deformation level in tensile fractured, press brake bent, and roll bent samples.

Stressful crystal histories recorded around melt inclusions in volcanic quartz

Magma ascent and eruption are driven by a set of internally and externally generated stresses that act upon the magma. We present microstructural maps around melt inclusions in quartz crystals from six large rhyolitic eruptions using synchrotron Laue X-ray microdiffraction to quantify elastic residual strain and stress. We measure plastic strain using average diffraction peak width and lattice misorientation, highlighting dislocations and subgrain boundaries. Quartz crystals across studied magma systems preserve similar and relatively small magnitudes of elastic residual stress (mean 53–135 MPa, median 46–116 MPa) in comparison to the strength of quartz (~ 10 GPa). However, the distribution of strain in the lattice around inclusions varies between samples. We hypothesize that dislocation and twin systems may be established during compaction of crystal-rich magma, which affects the magnitude and distribution of preserved elastic strains. Given the lack of stress-free haloes around faceted inclusions, we conclude that most residual strain and stress was imparted after inclusion faceting. Fragmentation may be one of the final strain events that superimposes stresses of ~ 100 MPa across all studied crystals. Overall, volcanic quartz crystals preserve complex, overprinted deformation textures indicating that quartz crystals have prolonged deformation histories throughout storage, fragmentation, and eruption.

Rolling Contact Fatigue Damage Analysis of G10CrNi3Mo Steel Bearing Inner Ring by X-ray Measurements

Contact fatigue is the main failure model for bearing systems in steel rolling mills. Characterizing the degree of contact fatigue damage is important for predicting its operating life. In this paper, the X-ray diffraction method (XRD) is used to measure the residual stress state and the diffraction peak width (FWHM, full width at half maximum) of six samples with different degrees of contact fatigue failure. The results show that surface residual stress values increased by more than 70% compared with the original state, while the diffraction peak width values decreased by more than 7% and were strongly correlated with the degree of contact fatigue damage. The XRD measurement of the bearing inner ring enables the characterization of the evolution of the residual stress state and grain distortion due to damage development. FWHM values may be considered an indicator for predicting the degree of contact fatigue.

Relating the combinatorial materials chip mapping to the glass-forming ability of bulk metallic glasses via diffraction peak width

There is a gap between the cooling rate of thin film deposition (∼108 K/s) and bulk metallic glass (BMG) casting (∼103 K/s). In this work, we tried to corelate the glass-forming range (GFR) determined from the combinatorial materials chip (CMC) with the glass-forming ability (GFA) of BMG. Data from five CMCs and the reported critical casting diameter (Dmax) of BMGs were used as the dataset. It is found that the full-width at half maximum (FWHM) of the first sharp diffraction peak (FSDP) is a good indicator of the GFA of BMG as suggested by Liu et al. [1]. Strong positive correlations between the FWHM and Dmax are shown in the Zr-, Ag-, Cu-, Fe-, La-, and Mg-based BMG systems. Furthermore, the Pearson correlation coefficients of the symbolic regression (SR) models indicate possible similarity in the GFA natures of the Ag-Zr, Cu-Zr, Cu-Ag, and Mg-La pairs.

Assessment of residual strain in laser shock peened additive manufactured Inconel 718 using synchrotron X-ray diffraction

The through-thickness residual strain profile due to laser shock peening (LSP) of an additively-manufactured IN718 sample is shown for the first time. The results provide tantalising insight into the potential of fatigue life extension of additive-manufactured samples using LSP. Residual strains were measured in as-manufactured and peened samples using state-of-the-art synchrotron radiation. Significant beneficial compressive in-plane residual strains, extending to 1.0 mm depth, were observed due to the peening process. No phase changes were observed due to LSP. A periodic strain variation was observed arising from the layer-by-layer manufacturing strategy of the samples. The peened sample showed no increase in diffraction peak width in the near-surface regions. This is contrary to reported studies using wrought laser shock peened alloys and suggests less grain disruption in additively-manufactured peened samples. The results are timely given a current drive to adopt additive-manufacturing for a step-change in efficiency of aero-engine component production.

Evaluating the phonon-phason coupling strength of an Al-Ni-Co decagonal quasicrystal

Recently, a novel method was proposed to probe the phonon-phason coupling effect in quasicrystals, and it was applied to an Al-Pd-Mn icosahedral quasicrystal. In this study, the method was applied to an Al-Ni-Co decagonal quasicrystal with a periodic layered structure of a two-dimensional quasicrystal. We applied elastic phonon strain along a 2-fold (aperiodic) axis in the quasicrystal plane at high temperatures with active phasons. Then, the phason strain was induced to the quasicrystal, which was demonstrated by the phason momentum (G ⊥) dependences of the powder X-ray diffraction peak widths. In contrast, when we applied phonon strain along the 10-fold periodic axis, no appreciable phason strain was observed to be induced. These results present clear evidence on the presence of phonon-phason coupling in a decagonal quasicrystal. The shape and width of the powder X-ray diffraction peaks were calculated based on the generalized elasticity of quasicrystals. The absolute value of the phonon-phason coupling constant was evaluated by quantitatively comparing the calculated results with the measured diffraction peaks.

Study on the surface integrity of 7050 aluminum alloy with different crystal orientations during high-speed machining

This paper investigates the effect of crystal orientations and machining parameters on the surface integrity of 7050 aluminum alloy in high-speed machining. Three groups of pre-compression deformations (10%, 15%, and 20%) are performed on the aluminum alloy to fabricate specimens with different crystal orientations. A single-factor dry-cutting experiment was designed, and the surface roughness, surface morphology and defects, work hardening, and X-ray diffraction (XRD) were tested. The results show that the 15% pre-deformed 7050 aluminum alloy specimen had lower surface roughness and the best surface quality under the same cutting parameters. The surface roughness of 7050 aluminum alloy with different crystal orientations tended to first increase and then decrease with the increase of the cutting speed, and the surface roughness was positively correlated with the cutting depth and feed rate. Under different cutting parameters, the machined surfaces of 7050 aluminum alloy specimens with different crystal orientations exhibited different degrees of plowings, apophysis, sticky chips, and pits. Moreover, the degree of work hardening of the 15% pre-deformed 7050 aluminum alloy specimen was small, while that of the 20% pre-deformed specimen was more serious. XRD analysis demonstrated that the diffraction peak width of the 10% pre-deformed 7050 aluminum alloy specimen slightly increased with the increase of the cutting depth. Moreover, the (111) and (200) diffraction peak intensities of the 15% pre-deformed 7050 aluminum alloy specimen increased with the increase of the cutting speed, and there was no obvious Al2CuMg phase on the machined surface of the 20% pre-deformed specimen.

Anomalous high-temperature quasi-linear superelasticity of Ni-Fe-Ga-Co shape memory alloy

The superelasticity of shape memory alloys is associated with the martensitic transformation which has been widely used in engineering applications. Here, we clarify quasi-linear superelasticity in Ni-Fe-Ga-Co shape memory alloy exhibiting a recovery strain of 3.58% at 573 K, which is far above the martensitic transformation temperature. Real-time in-situ neutron diffraction measurement was used to explore the underlying quasi-linear superelasticity mechanism via tracing the structural evolution during cyclic compression loading. Neutron diffraction observation showed that the superelasticity is correlated with stress-induced continuous variation of lattice parameter. The in-situ neutron diffraction provides the direct evidence on the anomalous diffraction peak width broadening, which mainly stems from the spatial heterogeneity in strain. The excessive Co doping is responsible for the decrease in stacking-fault energy leading to an increase in stacking faults, which suppresses the martensitic transformation and triggers the nucleation of the weak first-order phase under the external stress. The study provides insights into the interplay between superelasticity and structural transformation in shape memory alloys, and it is also instructive for understanding the anomalous high-temperature quasi-linear superelasticity in functional materials. • The quasi-linear superelasticy of Ni-Fe-Ga-Co shape memory alloy is caused by the weak first-order transformation. • The quasi-linear superelasticity of Ni-Fe-Ga-Co exhibits a recovery strain of ~3.58% at 573 K, which is rarely reported. • The excessive Co is account for trigger the nucleation of the weak first-order phase under the external stress.

Nanoscale Mechanism of Moisture-Induced Swelling in Wood Microfibril Bundles.

Understanding nanoscale moisture interactions is fundamental to most applications of wood, including cellulosic nanomaterials with tailored properties. By combining X-ray scattering experiments with molecular simulations and taking advantage of computed scattering, we studied the moisture-induced changes in cellulose microfibril bundles of softwood secondary cell walls. Our models reproduced the most important experimentally observed changes in diffraction peak locations and widths and gave new insights into their interpretation. We found that changes in the packing of microfibrils dominate at moisture contents above 10–15%, whereas deformations in cellulose crystallites take place closer to the dry state. Fibrillar aggregation is a significant source of drying-related changes in the interior of the microfibrils. Our results corroborate the fundamental role of nanoscale phenomena in the swelling behavior and properties of wood-based materials and promote their utilization in nanomaterials development. Simulation-assisted scattering analysis proved an efficient tool for advancing the nanoscale characterization of cellulosic materials.

Synergetic promotion of 4Mn10Ce/γ-Al2O3 catalyst to Pt/xBa/Ce0.5Zr0.5O2 catalysts for NOx removal from diesel exhausts

In this investigation, Pt/xBa/Ce0.5Zr0.5O2 catalysts were prepared by deposition and incipient wetness impregnation method and the physio-chemical properties of samples were characterized with XRD and BET. The experiments were carried out to evaluate the effect of 4Mn10Ce/γ-Al2O3 on the removal of NOx over the Pt/xBa/Ce0.5Zr0.5O2 catalysts and NO-TPD was employed for determining the NOx adsorption. The results showed that the larger diffraction peak width of Ce-Zr oxides and specific area were found over Pt/15Ba/Ce0.5Zr0.5O2. Based on the NOx storage and storage-reduction experiments, it was found that the decline of NOx storage efficiency was attributed to the decomposition of nitrites and nitrates under high temperatures beyond 350℃, and the inhibition of reactions of NOx with Ba by the NO oxidation. NO2 was stored more easily and faster than NO, which contributed to NOx storage after 4Mn10Ce/γ-Al2O3 catalyst added. The stability of stored species was undermined at higher temperature due to H2 consumption by 4Mn10Ce/γ-Al2O3 catalyst leading to shortage of reductant and more reaction heat. The optimal concentration of O2 at around 7.5% can provide more OⅡ for the oxidation process of NO and improve the performance of NOx reduction.

Hard and electrically conductive multicomponent diboride-based films with high thermal stability

We report high-quality, hard (31–41 GPa), crack-resistant (hardness-to-effective Young's modulus ratio of 0.13–0.16) and electrically conductive (2.8–4.2 × 105 S m−1) HfB2-based ceramic materials with high thermal stability. The materials were prepared in the form of well adhesive films using a simple deposition process: pulsed magnetron sputtering (B4C target overlapped by metal stripes) onto floating substrates. We go through a wide range of compositions resulting from incorporating five other metals (Ti, Y, Zr, Ho or Ta) which partially replace Hf, and focus on the effect of the number and characteristics of elements in the metal sublattice. Regardless of the number of incorporated elements, no segregation to more than one AlB2-type crystalline phase was observed. Growing number of metal elements leads to decreasing crystal size as indicated by the width of diffraction peaks, strongly decreasing compressive stress to less than 2 GPa and slightly decreasing hardness and electrical conductivity. The experimental data are explained by Monte-Carlo calculations of the energy delivered into the growing films. The thermal stability of septenary diboride-based films Hf8Zr4Ti4Ta4Y5B60C9 and Hf10Zr4Ti4Ta4Ho5B58C9 was superior to that of quaternary films Hf22Y5B58C9 and Hf22Ho5B58C9 when annealed to 1300 °C. Both the single solid solution crystalline phase (X-ray diffraction) and the dense and pinhole-free structure (scanning electron microscopy) were observed for the septenary films not only before but also after annealing. The results are important for the design and industry-friendly preparation of thin-film materials combining multiple functional properties for various technological applications.

Experimental and Numerical Stress State Assesment in Refill Friction Stir Spot Welding Joints

Abstract Refill Friction Stir Spot Welding (RFSSW) is a technology used for joining solid materials that was developed in Germany in 2002 by GKSS-GmbH as a variant of the conventional friction stir spot welding (FSSW) [1]. In the RFSSW technology, the welding tool consists of a fixed outer part and rotating inner parts, which are called a pin and a sleeve. The tool for RFSSW is designed to plasticize the material of the parts to be joined by means of a rotary movement. The design of the tool allows independent vertical movement of both elements of the welding tool. This allows obtaining spot welds without creating holes that could weaken the structure. The main advantage of RFSSW is the potential for replacing the technologies that add weight to the structure or create discontinuities, such as joining with screws or rivets. Thus, RFSSW has great potential in the automotive, shipbuilding and aviation industries. Furthermore, the technology can be used to join different materials that could not be connected using other joining methods. The main objective of this work is to understand the physical and mechanical aspects of the RFSSW method – including the residual stress state inside the weld and around the joint. The results of the investigations can help to determine optimal parameters that could increase the strength and fatigue performance of the joint and to prove the significant advantage of RFSSW connections over other types of joints. The work assumes the correlation of two mutually complementary investigation methods: numerical analyses and experimental studies carried out with diffraction methods. The comparison between numerical and experimental results makes potentially possible the determination of degree of fatigue degradation of the material by observing the macroscopic stress state and the broadening of the diffraction peak width (FWHM), which is an indicator of the existence of micro-stress related to the dislocation density and grain size.

Intact archeological human bones and age at death studied with transmission x‐ray diffraction and small angle x‐ray scattering

AbstractHigh‐energy, wide‐angle x‐ray scattering (WAXS, x‐ray diffraction) and small‐angle x‐ray scattering (SAXS) were used to study intact human second metacarpal bones (mc2) from two UK archeological sites. A novel method correcting for irregular mass distribution was applied in these transmission geometry experiments done at beamline 1‐ID of the Advanced Photon Source. The authors asked whether there were age‐at‐death‐related changes in carbonated apatite (cAp) lattice parameters and whether SAXS could detect collagen D‐period peaks in the archeological mc2. For each of the two sites, Ancaster and Wharram Percy in England, six female mc2s were studied; for each site, two were from each of three age‐at‐death cohorts (young, 18–29 years; middle, 30–49 years; old ≥50 years) along with a modern control mc2. The Rietveld method was applied to the WAXS patterns to provide precise lattice parameter values. The cAp lattice parameters did not correlate with age‐at‐death estimated from dental wear. From WAXS and the 00.2 diffraction peak widths, four archeological mc2s possessed coherently scattering domain lengths (crystallite c‐axis sizes) that matched that of the modern mc2; SAXS revealed the same four archeological mc2 had D‐period peak intensities equivalent to that of the modern mc2. The other eight archeological mc2s had significantly larger crystallite sizes (than the modern mc2) and weak or absent D‐period peaks, differences attributed to diagenetic changes. Based on these data, the authors suggest that WAXS 00.2 peak width and SAXS D‐period peak intensity can be used with intact bones to select those likely to retain largely unaltered tissue nanostructure, which might be required for other analyses. Taken as a whole, the results suggest detecting age‐related deterioration in nanostructural features may be difficult in bone showing significant bioerosion.

The Characteristic Analysis of Caffeine Molecularly Imprinted Polymers Synthesized Using The Cooling-Heating Method, for Application as a Sensor Material

The cooling-heating method was used to successfully synthesize molecularly imprinted polymers on caffeine. Caffeine was used as a template and mixed with chloroform solvent, methacrylic acid as a monomer, ethylene glycol dimethacrylate as a cross-linker, and benzoyl peroxide as an initiator. The solution was stirred for 15 minutes and placed in a vial. Then it was placed in a cooler with a temperature of -5○C for 60 minutes and then inserted into an oven with an increasing temperature at 75○C, 80○C, and 85○C for 3, 2 and 1 hour, respectively. Furthermore, the repeated washing process resulted in solid polymer, which was subjected to template leaching to produce polymers with specific cavities called molecularly imprinted polymers (MIP). The resulting caffeine polymer and MIP were tested using SEM, FTIR, and XRD methods. In addition, the SEM image analysis data showed 388 cavities in the polymer after template leaching, compared to the 121 cavities in the unwashed polymer. This result was supported by the FTIR spectrum analysis which showed that caffeine MIP has a higher transmittance value than the polymer. Therefore, the caffeine concentration was significantly reduced after the leaching process. The XRD spectra showed that caffeine MIP had a smaller halfmaximum diffraction peak width (FWHM) compared to the polymer. Also, the low FWHM value depicted a larger crystalline size in the caffeine MIP compared to the polymer.

Effect of Citrate on the Size and the Magnetic Properties of Primary Fe3O4 Nanoparticles and Their Aggregates

The size, size distribution and magnetic properties of magnetite nanoparticles (NPs) prepared by co-precipitation without citrate, in the presence of citrate and citrate adsorbed post-synthesis were studied by X-ray Diffraction (XRD), Dynamic Light Scattering (DLS), Electron Paramagnetic Resonance (EPR) and magnetization measurements. The aim of this investigation was to clarify the effect of citrate ions on the size and magnetic properties of magnetite NPs. The size of the primary NPs, as determined by analysing the width of diffraction peaks using various methods, was ca. 10 nm for bare magnetite NPs and with citrate adsorbed post-synthesis, whereas it was around 5 nm for the NPs co-precipitated in the presence of citrate. DLS measurements show that the three types of NPs form aggregates (100–200 nm in diameter) but the dispersions of the citrate-coated NPs are more stable against sedimentation than those of bare NPs. The sizes and size distributions determined by XRD are in good agreement with those of the magnetic domains obtained by fitting of the magnetization vs. magnetic field intensity curves. Magnetization vs. magnetic field intensity curves show that the three kinds of sample are superparamagnetic.

X-ray rocking curve imaging on large arrays of extremely tall SiGe microcrystals epitaxial on Si

This work investigates layers of densely spaced SiGe microcrystals epitaxially formed on patterned Si and grown up to extreme heights of 40 and 100 µm using the rocking curve imaging technique with standard laboratory equipment and a 2D X-ray pixel detector. As the crystalline tilt varied both within the epitaxial SiGe layers and inside the individual microcrystals, it was possible to obtain real-space 2D maps of the local lattice bending and distortion across the complete SiGe surface. These X-ray maps, showing the variation of crystalline quality along the sample surface, were compared with optical and scanning electron microscopy images. Knowing the distribution of the X-ray diffraction peak intensity, peak position and peak width immediately yields the crystal lattice bending locally present in the samples as a result of the thermal processes arising during the growth. The results found here by a macroscopic-scale imaging technique reveal that the array of large microcrystals, which tend to fuse at a certain height, forms domains limited by cracks during cooling after the growth. The domains are characterized by uniform lattice bending and their boundaries are observed as higher distortion of the crystal structure. The effect of concave thermal lattice bending inside the microcrystal array is in excellent agreement with the results previously presented on a microscopic scale using scanning nanodiffraction.

Structural transitions of 4:1 methanol–ethanol mixture and silicone oil under high pressure

A 4:1 (volume ratio) methanol–ethanol (ME) mixture and silicone oil are two of the most widely used liquid pressure-transmitting media (PTM) in high-pressure studies. Their hydrostatic limits have been extensively studied using various methods; however, the evolution of the atomic structures associated with their emerging nonhydrostaticity remains unclear. Here, we monitor their structures as functions of pressure up to ∼30 GPa at room temperature using in situ high-pressure synchrotron x-ray diffraction (XRD), optical micro-Raman spectroscopy, and ruby fluorescence spectroscopy in a diamond anvil cell. No crystallization is observed for either PTM. The pressure dependence of the principal diffraction peak position and width indicates the existence of a glass transition in the 4:1 ME mixture at ∼12 GPa and in the silicone oil at ∼3 GPa, beyond which a pressure gradient emerges and grows quickly with pressure. There may be another liquid-to-liquid transition in the 4:1 ME mixture at ∼5 GPa and two more glass-to-glass transitions in the silicone oil at ∼10 GPa and ∼16 GPa. By contrast, Raman signals only show peak weakening and broadening for typical structural disordering, and Raman spectroscopy seems to be less sensitive than XRD in catching these structural transitions related to hydrostaticity variations in both PTM. These results uncover rich pressure-induced transitions in the two PTM and clarify their effects on hydrostaticity with direct structural evidence. The high-pressure XRD and Raman data on the two PTM obtained in this work could also be helpful in distinguishing between signals from samples and those from PTM in future high-pressure experiments.

X-ray powder diffraction analysis of the phase composition of α- and near-α-titanium alloys

Titanium alloys are widely used as materials for the elements of nuclear power plants, which are subject to high reliability requirements. The goal of the study is to develop X-ray diffraction analysis of the phase composition of α - and near- α -titanium alloys. Surface treatment of the samples of titanium alloys PT-3V, PT-7M and VT1-0 was carried out by mechanical, electrochemical polishing and chemical etching. It is shown that PT-3V and PT-7M alloys are characterized by a mixed structure consisting of α - and α ’-phases with precipitation of submicron particles of the β -phase along the grain boundaries. The results of X-ray diffraction analysis of the samples obtained on an X-ray diffractometer Shimadzu XRD-7000 (Cu K α radiation) were compared with the data of metallography and electron microscopy. It is shown that the results of X-ray diffraction analysis strongly depend on the method, quality and duration of the surface treatment of the samples. Electrochemical polishing and acid treatment reduce the width of diffraction peaks and lead to a more pronounced manifestation of their «fine» structure thus demonstrating the presence of at least two crystalline phases in the alloys. «Splitting» of the main X-ray peaks of titanium is a consequence of the fine structure of primary X-ray radiation ( K α 1,2 -doublet). Presence of «fine» structure of X-ray peaks and correlation between the intensities of different peaks appears to depend essentially on the mode and quality of surface treatment of the titanium alloy thus reducing the reliability of quantitative analysis of the phase composition of titanium alloys without verification of the results by direct methods of studying alloy structure.