Role of Sn as a Process Control Agent on Mechanical Alloying Behavior of Nanocrystalline Titanium Based Powders

In this study, the e ects of Sn as a process control agent (PCA) on the final powder sizes, morphology, homogenization and alloying process of a new titanium alloy were investigated. Two kinds of powders, Ti10Ta8Mo and Ti10Ta8Mo3Sn (wt %), were prepared using a mechanical alloying process. For the Ti10Ta8Mo3Sn (wt %) alloy, the Sn element was used as PCA to enhance the milling process in the planetary ball mill. The milling process of both compositions was carried out with 200 rpm for 10, 15, 20, 40, 60, 80 and 100 h. The results confirmed that using Sn as a proces control agent can result in a relatively good size distribution and better yield performance compared to samples without Sn addition. The phase analysis using X-ray di raction proved the formation of the nanocrystalline phase and the partial phase transformation from to nanocrystalline phases of both alloy compositions. The Scaning Electron Micoscope- Backscattered Electrons SEM-BSE results confirmed that the use of Sn as the PCA can provide a better homogenization of samples prepared by at least 60 h of ball milling. Furthermore, the presence of Sn yielded the most uniform, spheroidal and finest particles after the longest milling time

Effect of high energy ball milling on the structure and phase decomposition of the ultiferroic Bi5Ti3FeO15 ceramics

The paper presents the results of the Bi5Ti3FeO15 multiferroic phase stability analysis during high-energy ball milling aimed at obtaining fine dispersion ceramic powder. The X-ray diffraction and transmission electron microscopy methods were used to analyse the structure and verify the degree of crystallite dispersion. Structural data analysis was carried out using the Rietveld method. To carry out the analysis of the morphology, the scanning electron microscopy was used. The results that were obtained showed that the high energy ball milling process results in the decomposition of the initial ceramics, where finally Bi5Ti3FeO15 and Bi are obtained. An increase in the proportion of the amorphous phase and an increase in the dispersion of the grains and crystallites of the powder that occurs with an increase in the milling time were observed[…

Structure Characterization of Biomedical Ti-Mo-Sn Alloy Prepared by Mechanical Alloying Method

The study presents the results of the influence of high energy milling on the structure of the new Ti–15Mo– 5Sn [wt%] alloy for biomedical applications. During testing the powders were milled for the following milling times: 5, 15, 30, and 45 h. The milled powders were characterized by X-ray diffraction, scanning and transmission electron microscopy methods. Observation of the powder morphology after various stages of milling leads to the conclusion that with the increase of the milling time the size of the powder particles as well as the degree of aggregation change. However, a clear tendency of particles reduction at every stage of the mechanical alloying process is clearly observed. The X-ray diffraction results confirmed the presence of the and phases, and molybdenum. It has been found that the reflections from the Sn phase disappeared after five hours of milling, suggesting that the Sn and Ti alloying took place, leading to the creation of a titanium-based solid solution. After 30 and 45 h of mechanical alloying the formation of the -Ti phase, the final share of which is 46(4) wt%, was observed. Furthermore, it was found that a diffraction line broadening with the increase of the milling time results from reduction of the crystallite size and an increase in the lattice distortion. The maximum level of the reduction of the crystallite size was obtained after 45 h of milling. The maximum degree of the unit cells reduction for all phases present in the powder that was being milled was also observed for this milling time

Influence of high energy milling time on the Ti-50Ta biomedical alloy structure

Nickel-free titanium alloys are a promising research direction in the field of biomedical materials. Current literature reports indicate that there is a possibility of using the Ti–Ta alloys in medicine since these alloys have had satisfactory results as far as biocompatibility, resistance to corrosion and mechanical properties are concerned, which is an important aspect while considering the use of this alloy for long-lasting bone implants. This article presents the results of a high-energy milling process with the use of Ti and Ta powders. The ball-milling process was carried out for various times, including 20, 40, 60, 80, and 100 h. The samples were characterized by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The research confirmed partial synthesis of the materials during the process of high energy ball milling

Phase composition of urban soils by X-Ray diffraction and Mössbauer spectroscopy analysis

The m ain purpose of this study was to identify the mineral composition of soil sample taken from the upper layer of topsoil. High absorption of chemical substance is a characteristic for humus-organic layer of topsoil. The source of those substance could be a pollutant emitted to the atmosphere by human activity. The research area includes Upper Silesia region, which is the most industrial region of Poland. In the present study, the phase composition of the top soil separates were analyzed by using X-ray diffraction and Mössbauer spectroscopy. X-ray diffraction analysis revealed the presence of seven mineral phases in the material magnetic separated by lower current (quartz, illite, kaolinite, Fe3+ oxides, hematite, magnetite and pyrite). In case of higher current were identified four phases (quartz, muscovite, kaolinite and K0.94 Na0.06(AlSi3O8)). Mössbauer spectroscopy was used for an extensive analysis of iron-containing phases (pyrrhotite, magnetite, aluminosilicate oxides with Fe3+ and kaolinite/Fe2+ silicate)

Microstructure evolution of Ti/ZrO2 and Ti/Al2O3 composites prepared by powder metallurgy method

The current study were performed in order to assess the fabrication possibility of the metal-ceramic composites based on nanocrystalline substrates. The influence of the variable time of the high energy ball-milling (10, 30 and 50 h) on the structure, pores morphology and microhardness of Ti/ZrO2 and Ti/Al2O3 compositions was studied. The X-ray diffraction analysis confirmed the composite formation for all milling times and sintering in the case of Ti/ZrO2 system. Decomposition of substrates during milling process of Ti/Al2O3 system was also observed. Additionally, the changes of lattice parameter as a function of milling time were studied. The morphology of powders and the microstructure of the sintered samples were observed by scanning electron microscopy (SEM). Also, analysis of microhardness and pores structure were performed

Fabrication and characterization of new functional graded material based on Ti, Ta, and Zr by powder metallurgy method

In view of the aging population and various diseases worldwide, the demand for implants has been rapidly increasing. Despite the efforts of doctors, engineers, and medical companies, the fabrication of and procedures associated with implants have not yet been perfected. Therefore, a high percentage of premature implantations has been observed. The main problem with metal implants is the mechanical mismatch between human bone and the implant material. Zirconium/titanium-based materials with graded porosity and composition were prepared by powder metallurgy. The whole samples are comprised of three zones, with a radial gradient in the phase composition, microstructure, and pore structure. The samples were prepared by a three-step powder metallurgy method. The microstructure and properties were observed to change gradually with the distance from the center of the sample. The x-ray diffraction analysis and microstructure observation confirmed the formation of diffusive connections between the particular areas. Additionally, the mechanical properties of the obtained materials were checked, with respect to the distance from the center of the sample. An analysis of the corrosion properties of the obtained materials was also carried out

Electrodeposition of copper and brass coatings with olive-like structure

One method of creating a brass coating is through electrodeposition, which is most often completed in cyanide galvanic baths. Due to their toxicity, many investigations focused on the development of more environmentally friendly alternatives. The purpose of the study was to explore a new generation of non-aqueous cyanide-free baths based on 1-ethyl-3-methylimidazolium acetate ionic liquids. The study involved the formation of copper, zinc, and brass coatings. The influence of the bath composition, cathodic current density, and temperature was determined. The obtained coatings were characterized in terms of their morphology, chemical composition, phase composition, roughness, and corrosion resistance. It was found that the structure of the obtained coatings is strongly dependent on the process parameters. The three main structure types observed were as follows: fine-grained, porous, and olive-like. To the best knowledge of the authors, it is the first time the olive-like structure was observed in the case of an electrodeposited coating. The Cu-Zn coatings consisted of 19–96 at. % copper and exhibited relatively good corrosion resistance. A significant improvement of corrosion properties was found in the case of copper and brass coatings with the olive-like structure

Microstructure and porosity evolution of the Ti-35Zr biomedical alloy produced by elemental powder metallurgy

In the present study, the structure and porosity of binary Ti–35Zr (wt.%) alloy were investigated, allowing to consider powder metallurgy as a production method for new metallic materials for potential medical applications. The porous Ti–Zr alloys were obtained by milling, cold isostatic pressing and sintering. The pressure during cold isostatic pressing was a changing parameter and was respectively 250, 500, 750 and 1000 MPa. The X-ray diffraction study revealed only the α phase, which corresponds to the Ti–Zr phase diagram. The microstructure of the Ti–35Zr was observed by optical microscopy and scanning electron microscopy. These observations revealed that the volume fraction of the pores decreased from over 20% to about 7% with increasing pressure during the cold isostatic pressing. The microhardness measurements showed changes from 137 HV0.5 to 225 HV0.5

Application of Mössbauer spectroscopy for identification of iron-containing components in Upper Silesian topsoil being under industrial anthropopressure

The main objective of the presented preliminary study was the identification of iron-containing phases. Iron-containing phases had accumulated in organic topsoil horizons collected from an area that has long been a ected by the steel industry and emissions from power plants. X-ray di raction and Mössbauer spectroscopy methods were used for the determination of the iron-containing mineral phases in topsoil subsamples which, after two-staged separation, varied in terms of magnetic susceptibility and granulometry. The Mössbauer spectra were recorded using paramagnetic and magnetic components, although the latter occurred only in the strongly magnetic fraction. The central part of spectra was fitted by two doublets (D1 and D2), which were identified as aluminosilicates. Simultaneously, the experimental spectra were described using several Zeeman sextets (Z1, Z2, and Z3) corresponding to the occurrence of hematite and magnetite-like phases with iron in tetrahedral and octahedral sites. Identification of magnetic phases in the tested material, including hematite, led to the conclusion that soil contamination in the studied area was presumably caused by emissions from a nearby power plant. Magnetite-like phases with a di erent iron content detected in topsoil samples could be related to metallurgical and coking processes, reflecting the specificity of the industrial area from which the samples were taken. The specific composition of the iron-containing aluminosilicates also illustrated the intense and long-lasting impact of the steel and coking industries on the studied area