Dispersive Spectroscopy Research Articles

Synthesis and Characterization of X–MOF/AC (X=tin or copper) Catalysts for the Acetylene Hydrochlorination

AbstractIn this study, metal organic framework/activated carbon catalysts (X–MOF/AC, where X=Sn or Cu) were synthesized using a facile method and used for the acetylene hydrochlorination reaction. The prepared catalysts were characterized using Fouriertransform infrared spectroscopy (FTIR), X‐ray diffraction analysis(XRD), nitrogen adsorption‐desorption analysis, thermo‐gravimetric analysis (TGA), acetylene temperature‐programmed desorption experiments (C2H2‐TPD), hydrogen temperature‐programmed reduction experiments (H2‐TPR), X‐ray photoelectron spectroscopy (XPS) and scanning electron microscopy‐energy dispersive spectroscopy (SEM‐EDS). Compared with Cu–MOF/AC, Sn‐MOF/AC behaved the highest acetylene conversion of 93.5% under the conditions of 200 °C and an acetylene gas space velocity of 30 h−1. Furthermore, XRD, TGA and SEM‐EDS results showed that Sn‐MOF and Cu–MOF possesse different morphology and thermalstability, respectively. Additionally, C2H2‐TPD and TGA results indicated that Sn‐MOF/AC displays the higher acetylene adsorption and the better anti‐coking ability as compare to Cu–MOF/AC.

Analysis of 410NiMo coating deposited by thermal spray in CA6NM martensitic stainless steel against erosion by cavitation

For most applications, martensitic stainless steels are subject to operating conditions where good mechanical properties and wear resistance are required. Soldering soft martensitic stainless steels features decreased tenacity of the welded joint which, along with the residual stresses, can shorten the life of component and accelerate the cavitation process. In order to increase the strength of the martensitic structures, thermal spraying is used to produce coatings, laid without resulting in thermal cycles that influence the structural integrity of the coated steels. This work was deposited by the electric arc and wire flame, the 410NiMo martensitic stainless steel, in wire and rod form, respectively, on the substrate of the martensitic stainless steel CA6NM. The samples were sent to Vickers microhardness tests and accelerated cavitation, according to ASTM G32-10. The results were obtained through optical microscopy, X-ray diffraction, SEM, and dispersive energy spectroscopy (DES); the samples featured high adhesion, low porosity, and cavitation erosion–resistant coatings. The thermal spray is suitable for the application of this type of coating.

Characterization of magnetic iron phases in IMPACTITES by MÖSSBAUER spectroscopy

We present the results for two mineral samples from the Natural History Museum (MHN) of San Marcos National University (UNMSM) classified as: potential meteoritic samples coded MHN08 and MHN09 with an iron content of about 10% that were characterized using physical techniques such as energy dispersive X-ray fluorescence (EDXRF), X-ray diffractometry (XRD) and transmission Mossbauer spectroscopy (TMS). This study reveals that the samples consist mainly of quartz, goethite and impactites such as coesite, stishovite, and ringwoodite, and therefore should be classified as impactites. 57Fe Mossbauer spectroscopy allowed the observation of three subspectra, two of them assigned to magnetic iron phases, and a third subspectrum assigned to a superparamagnetic phase. An important contribution of TMS is the possibility of observing this superparamagnetic phase which is assigned to goethite which at RT shows a very broad area (80.8%), and at liquid helium temperature appears as a magnetically ordered sextet.

Fabrication of ZnO-Al2O3-PTFE Multilayer Nano-Structured Functional Film on Cellulose Insulation Polymer Surface and Its Effect on Moisture Inhibition and Dielectric Properties

After a century of practice, cellulose insulating polymer (insulating paper/pressboard) has been shown to be one of the best and most widely used insulating materials in power transformers. However, with the increased voltage level of the transformer, research has focused on improving the insulation performance of the transformer’s cellulose insulation polymer. Considering the complex environment of the transformer, it is not enough to improve the single performance of the insulating polymer. In this study, a nano-structured ZnO-Al2O3-PTFE (polytetrafluoroethylene) multifunctional film was deposited on the surface of insulating pressboard by radio frequency (RF) magnetron sputtering. The effect of the multilayered ZnO-Al2O3-PTFE functional film on the dielectric and water contact angle of the cellulose insulating polymer was investigated. The scanning electron microscopy/energy dispersive spectrometry (SEM/EDS) showed that the nano-structured ZnO-Al2O3-PTFE functional film was successfully deposited on the cellulose insulation pressboard surface. The functional film presented an obvious stratification phenomenon. By analyzing the result of the contact angle, it was found that the functional film shields the hydroxyl group of the inner cellulose and improves hydrophobicity. The AC breakdown field strength of the treated samples was obviously increased (by 12 to ~17%), which means that the modified samples had a better dielectric insulation performance. This study provides a surface modification method to comprehensively improve electrical properties and the ability to inhibit the moisture of the cellulose insulating polymer, used in a power transformer.

Practical Considerations Regarding the Electrodeposition of Ni-Cu Layers as Potential Supercapacitors Plates

In this paper the properties of some Ni-Cu layers deposited onto a steel substrate were discussed. One has investigated the influence of the electrodeposition process on the final properties of the Ni-Cu layers, in order to see if these electrodeposited layers could be used as supercapacitor plates. The structural characterization was investigated by scanning electron microscopy and their composition by dispersive energy spectrometry. One has built a number of functional supercapacitors using Ni-Cu layer plates inserting in between them a separation membrane and their capacitance values were determined.

RECYCLING OF CONSTRUCTION WASTE USING HIGH-SPEED MILLING PROCESS: DETERMINATION OF WASTE CONCRETE

This paper deals with the use of high-speed milling process for recycling old concrete and direct determination of the potential of input waste. For this purpose, three different types of waste concrete were used: prefabricated railway sleeper, structural concrete of monolithic pillar and prefabricated drainage gutter. The paper directly examines the chemical and phase composition by XRF, X-Ray Diffraction (XRD), Energy Dispersive X-ray Spectrometry (EDS) and microscopic analysis, particle size distribution and pH of the recycled material. Results of those analysis are used to select suitable recycled material. The suitability of choice is supported by mechanical tests of 28-day old cement pastes, where the compressive strength and dynamic modulus of elasticity are observed properties. Specimens measuring 40 × 40 × 160mm are composed of 70 wt.% Portland cement and rest is micronized concrete. In all cases, the results are compared with the reference material.

Mechanical Characteristics of a Roll-Bonded Cu-Clad Steel Sheet Processed Through Incremental Forming

Incremental sheet forming (ISF) is an emerging cold forming process with a high economic payoff. In this study, the influence of the ISF process on the tensile properties of Cu-clad Steel sheet is analyzed experimentally. Depending on the forming conditions, the post-ISF values of yield strength, tensile strength, and ductility are found to range from 161 to 430, 288 to 449 MPa, and 4.93 to 16.62 pct, respectively. These properties show a strong dependence on several correlated quantities such as the applied plastic strain, grain size, and mean residual stress. As the plastic strain increases from 0.08 to 0.8, the width of the grain decreases from 8.11 to 5.78 µm and the residual stress increases from − 15 to − 131 MPa. In comparison to the unformed sheet, ISF enhances the yield strength (4.6 to 117 pct) and tensile strength (0.6 to 73 pct). The nature of change in ductility (− 67 to 117 pct), however, depends on the process conditions, especially the state of the unformed sheet (i.e., rolled/annealed) and the value of applied strain. In general, the rolled (or prestrained) sheet upon ISF experiences an increase in ductility. The annealed sheet, however, sees a drop in ductility when the forming strains are low (e.g., 0.4). X-ray diffraction (XRD) and electron dispersive spectroscopy (EDS) analyses confirm that no new phase formed during ISF.

Simultaneous determination of 25 pesticides in Zizania latifolia by dispersive solid-phase extraction and liquid chromatography-tandem mass spectrometry

An improved quick, easy, cheap, effective, rugged, and safe (QuEChERS) method combined with ultrapressure liquid chromatography tandem mass spectrometric method (UPLC-MS/MS) was developed to simultaneously determine 25 pesticides in Zizania latifolia. The samples were extracted with methanol(MeOH) and 0.1% formic acid (80:20, v/v) and cleaned with C18 absorbent and primary-secondary amine (PSA). LC separation was performed on a BEH C18 UPLC column under the condition of gradient elution with the mobile phase consisted of 0.5% formic acid (10 mM ammonium acetate)/MeOH. External standard calibration method with matrix-matched was used for quantification, and good linearity was obtained over a concentration range of 0.5–100 μg/l, with correlation coefficients greater than 0.9901. The limit of detection (LOD) and the limit of quantitation (LOQ) of the 25 pesticides were in the range of 0.2–1.0 µg/kg and 0.5–3.3 µg/kg, respectively. The recoveries ranged from 72% to 118%, and the relative standard deviations (RSDs) were less than 20%. Thus, the proposed method is suitable for the simultaneous determination of 25 pesticides in Z. latifolia.

Facile Synthesis of ZnS Nanoparticles for Detection of O-nitrophenol

The ZnS nanoparticles were synthesized by hydrothermal method using thioacetamide and zinc chloride as precursors, and characterized by X-ray diffractometer, scanning electron microscopy, transmission electron microscopy, energy dispersive spectrometer and AC impedance spectroscopy. Electrochemical behavior of O-nitrophenol at nano ZnS modified glassy carbon electrode was investigated, and the reduction mechanism was discussed. Determination of artificial samples using the standard addition method was proposed, and recoveries were in the range from 96.3 to 102.0% with RSD of 1.3–2.0% (n = 6).

Effect of electroplated interlayers on properties of cold-sprayed copper coatings on SS316L steel

Cold-sprayed copper (Cu) coatings have been recommended for the passivation of plasma-facing components in the vacuum vessel of Tokamaks. Therefore, research is under progress to develop such coatings with desired properties, which is still a challenging task. In the present work, the effect of nickel (Ni) and Cu electroplated interlayers on several properties of cold-spray copper coated SS316L steel was investigated. Further, the effect of heat-treatment on the developed coatings was also analyzed. The developed coatings were characterized by scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS), X-ray diffraction (XRD), microhardness, nanoindentation, macro-tensile, and lap-shear test/ adhesion testing, and porosity, density and, electrical and thermal conductivity measurements. The novelty of the article includes the in-situ micro-tensile investigations performed under SEM to reveal the fracture phenomenon for the coatings. It was observed that the heat-treatment, in general, improves the coating properties. Additionally, gamma (γ)-ray and heavy nuclei irradiation and thermal cyclic tests were performed to elucidate the actual environmental performance of the coatings. Based on the overall results of the study, the heat-treated Cu-coating developed on Ni-electroplated steel substrate was found to be the most suitable material for protecting the plasma-facing components.

Defects and the Formation of Impurity ‘Hot Spots’ in HgCdTe/CdZnTe

The formation of impurity ‘hot spot’ macro-defects—localized high impurity level contaminates—is examined. The evolution of macro-defects through their critical stages: as-received CdZnTe substrate, molecular beam epitaxy (MBE) prep etch, Te/oxide desorption and stabilization at deposition temp in MBE chamber, thin (200 nm) HgCdTe deposition, and thick (> 4 μm) MBE HgCdTe deposition, is analyzed. As-received CdZnTe wafers have small and large agglomerations of residual SiO2 and Al2O3 polishing grit. Additionally, macro-defects composed of organic residue, Cd(Zn)Te particulates, and additional impurities are also observed. The MBE preparation etch does not significantly alter the types of defects found on the wafer. The Te/oxide desorption process adds a small number of defects due to colloidal graphite particles. HgCdTe deposition introduces MBE spit defects and Hg droplet residue. There is significant movement of polishing grit and organic macro-defects during the various processing steps. Energy dispersive X-ray spectroscopy (EDS) analysis of MBE spit defects shows they are Cd rich with some of the spit defects containing high concentrations of impurities. The vertical gradient in Te concentration associated with the overgrowth on a metal rich MBE spit defect acts as an impurity pipe for Cu to travel toward the surface to become a ‘hot spot’ defect.

Dry sliding wear behaviour of Ti–6Al–4V pin against SS316L disc in vacuum condition at high temperature

ABSTRACTTi–6Al–4V alloy exhibit a unique combination of mechanical, physical, and chemical properties; that pronounced its desirability for implementation in the fields of aerospace, automobile, and chemical industries. The mechanisms, namely, strain rate response/adiabatic shear band (ASB) – effect of plastic deformation, tribo-chemical reaction and formation of the mechanically mixed layer (MML), can control wear behaviour of the alloy. Hence, the present work investigates the influence of these mechanisms in governing the tribological characteristics of the Ti6Al4V alloy aganist SS316L steel. The experiments were executed on a pin-on-disc tribometer under vacuum (2 × 10−5 Torr), by varying the temperature (25, 100, 200, 300 and 400°C) at constant sliding speed (0.01 ms−1) and load (137.3 N) conditions. Compression test was carried out at distinct strain rate (0.001 and 10 s−1) and temperature (25, 100 and 400°C) values, to investigate the occurrence of ASB. The scanning electron microscopy and energy dispersive X-ray spectroscopy analyses were used to evaluate the formation of appendage layers (oxides and MML) and the composition of wear debris, respectively. The wear rate of the Ti–6Al–4V alloy decreased with increment in temperature (room condition to 400°C) inside vacuum environ, governed by ASB and the presence of oxide layers.

MON-099 Particulates mixed in dialysate

When foreign bodies that cannot be metabolized enter the systemic circulation, they remain in the body and are often difficult to remove. Therefore, each country’s pharmacopoeia measures insoluble particulates that are unintentionally mixed into injections and manages quality control by the predetermined permissible range of insoluble particulates. However, the present Standard of Fluids for Hemodialysis and Related Therapies only stipulates the water quality standard for biological and chemical contaminants, but there is no standard for insoluble particulates in dialysate. We measured insoluble particulates in online prepared substitution fluid prepared from dialysate and substitution fluid for hemofiltration and evaluated the insoluble particulates using scanning electron microscopy/energy dispersive spectroscopy. We measured insoluble particulates in online prepared substitution fluid prepared by filtering dialysate using an endotoxin retentive filter installed in the central dialysis fluid delivery system and commercially-available substitution fluid for hemofiltration. We used the Light Obscuration Particle Count Test for measurement, as stipulated by Japanese pharmacopoeia. We evaluated the constituent elements of insoluble particulates using scanning electron microscopy/energy dispersive spectroscopy. We also measured silicon contained in reverse osmosis water used to prepare dialysate in the central dialysis fluid delivery system and substitution fluid for hemofiltration. The mean number of particles of ≥ 10 μm contained in the online prepared substitution fluid was 0.1–1 /mL and 0–0.1 /mL for particles of ≥ 25 μm. Insoluble particulate elements included carbon, oxygen, calcium, magnesium, and silicon. The silicon content of reverse osmosis water was 0.5 mg/L. The mean number of particles of ≥ 10 μm contained in substitution fluid for hemofiltration was 0.5 /mL, with no particles ≥ 25 μm. These insoluble particulates were composed of carbon and oxygen. The silicon content was 0.1 mg/L. Japanese pharmacopoeia stipulates that the number of insoluble particulates in 1 mL of injection fluid must be 25 or fewer for particles of ≥ 10 μm and 3 or fewer for particles of ≥ 25 μm. The numbers of insoluble particles in online prepared substitution fluid and substitution fluid for hemofiltration were within permissible ranges, as stipulated by Japanese pharmacopoeia. We presume that insoluble particulates in online prepared substitution fluid were calcium and magnesium precipitated from dialysate and silicon precipitated from reverse osmosis water. The insoluble particulates in the substitution fluid for hemofiltration were carbon and oxygen, which were presumed to be components of glucose based on the composition of hemofiltration substitution fluid.

Abstract 4859: MFP-FePt-GO nanocomposite promotes radiosensitivity of non-small cell lung cancer via activating caspase system and impairing DNA damage repair

Abstract Recent advances in nanomedicine provide promising alternatives for cancer treatment that may improve the survival and life quality of patients with cancer. A novel nanocomposite (MFP-FePt-GO) based on a lamellar-structure magnetic graphene oxide (GO) and polyethylene glycol drug delivery system was designed, synthesized and functionalized for co-delivery of metronidazole and 5-fluorouracil. The chemical synthesis efficiency was measured by Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and energy dispersive X-ray spectroscope. The morphology, dispersion and sizes of this nanocomposite were also measured with transmission electron microscope. This new nanocomposite exhibited good solubility, stability and biocompatibility. While no severe allergies, liver and kidney damage or drug-related deaths were observed, MFP-FePt-GO promoted radiosensitivity of non-small cell lung cancer (NSCLC) cells both in vivo and in vitro. MFP-FePt-GO imrpvoed the effects of radiation through activation of the caspase system and impairment of DNA damage repair. This novel nanocomposite also induced a reactive oxygen species burst, which suppressed the antioxidant protein expression and induced cell apoptosis. Furthermore, MFP-FePt-GO prevented the migration and invasion of NSCLC cells. Taken together, MFP-FePt-GO showed a synergistic anti-tumor effect with radiation in eliminating the tumors. With good safety and efficacy, this novel nanocomposite might be a potential radiosensitive agent for NSCLC patients. Citation Format: Shan Peng, Yingming Sun, Yuan Luo, Shijing Ma, Yan Gong, Conghua Xie. MFP-FePt-GO nanocomposite promotes radiosensitivity of non-small cell lung cancer via activating caspase system and impairing DNA damage repair [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4859.

Uranium brannerite with Tb(III)/Dy(III) ions: Phase formation, structures, and crystallizations in glass

AbstractUranium brannerite phases with terbium(III) or dysprosium(III) ions have been investigated. The precursors with molar ratio of 0.5:0.5:2 (Ln: U: Ti with Ln = Tb or Dy) were prepared and calcined at 750°C in argon. Sintering the pelletized samples in argon at 1200°C led to the formation of pyrochlore phases with TiO2 rutile and U‐rich oxides while sintering in air led to the formation of brannerite phases with the nominal composition close to Ln0.5U0.5Ti2O6 together with trace amounts of TiO2 rutile and LnUO4. Incorporating an excess of TiO2 (20 wt%) and sintering at higher temperature (1300°C) resulted in no obvious change to the phase equilibrium. As designed, pentavalent uranium has been proven to be dominant in these brannerite phases with diffuse reflectance spectroscopy. The relationships between the cell parameters and the ionic radii of the A‐site cations have been explored and rationalized from the structure point of view for a range of titanate brannerite phases (ATi2O6). In addition, the crystallization of Ln0.5U0.5Ti2O6 brannerite in glass has been achieved via heat treatment at 1200°C and confirmed with X‐ray diffraction, scanning electron microscopy‐energy dispersive spectroscopy and transmission electron microscopy–selected area electron diffraction.

Synthesis, Crystallographic, Monoclinic, Inflexible, Antifungal Assessment of Schiff based resin

The present study investigates the preparation of a newly prepared Schiff base BHNMXD and Schiff based resin PMBHNMXD via polymerization. The condensation or polymerization procedure was used with formaldehyde (HCHO) at temperature 70 to 80 ˚C for 2-3 h. The prepared Schiff base BHNMXD and its respective resinPMBHNMXD were recrystallized from methanol to attain pure resin. After successful synthesis of Schiff base and resin was characterized by different instrumental techniques such as; CHN, elemental microanalysis, thermogravimetric analysis (TGA) studies of Schiff based resin, energy- dispersive x-ray spectroscopy EDS mass spectrometry, E.I-MS (electron impact ionization), 1HNMR spectroscopy and MALDI-TOF mass spectrometry clearly investigated the molecular weight and structural information of synthesized compounds. The FT-IR spectra of resin PMBHNMXD showed stronger absorption band at 1632 cm-1 of azomethine >C=NH confirming the compound formation. The SEM analysis showed the morphology of Schiff base and resin showing, longitudinal spherical rough, inflexible and rigid structure. The structures and components were carefully investigated by X-ray diffraction .The crystallographic evaluation of Schiff base and its resin, aproved the monoclinic sharp crystalline structure. These active materials have shown high efficiency against the antifungal growth of Aspergillus Flavus (G-ve), Candida albicans (G-ve) and Aspergillus Niger (G-ve),by agar well diffusion method.

The microstructure and shear behavior of Zn–25Sn–xTi solder joints with Ni substrate

The effect of Ti addition on the shear behavior of a Zn–25Sn–xTi solder bonding with Ni substrate at 25 °C and 100 °C was investigated. The microstructures of the solder joints had three different phases, which are the Zn-rich phase, laminar Sn-Zn eutectic phase, and the intermetallic compound with some pores. The average atomic composition of the intermetallic compound was 16.38 at.% Zn and 81.46 at.% Ni corresponding to a ratio of Ni to Zn of 1:4.63. The Ni5Zn21 intermetallic compounds were confirmed by Wavelength dispersive spectroscopy and X-ray diffraction analysis. The addition of Ti refined the Zn-rich phase. Moreover, compared with Pb–5Sn/Ni, the Zn–25Sn–xTi/Ni solder joints exhibited superior shear strength at 25 °C and 100 °C. The mechanical properties of the solder joints were further investigated with nanoindentation tests. The Ni5Zn21 intermetallic layer exhibited the lowest value of plasticity parameter compared with the solder matrix and substrate. Accordingly, shear fracture tended to occur in the IMC layer at room temperature.

Corrosion behavior of under‐, peak‐, and over‐aged 6063 alloy: A comparative study

AbstractThe mechanical property of age‐hardenable Al‐alloys is governed by the state of ageing, which determines the microstructure and consequently, their corrosion behavior which is a vital aspect for a number of applications. This article presents a comparative assessment of corrosion behavior of under‐, peak‐ and over‐aged Al‐Mg‐Si alloy. Corrosion characteristics have been determined via immersion tests in 0.1 M ortho‐phosphoric acid solution and intergranular corrosion (IGC) tests. Corroded surfaces are examined by field emission scanning electron micrographs‐energy dispersive spectroscopy and 3D optical profilometer. The obtained results reveal that the corrosion rate at a specific immersion time as well as the depth of IGC increases in the order for under‐, peak‐, and over‐aged states. Irrespective of the state of ageing, corrosion loss increases linearly but the rate of corrosion decreases rapidly with increasing immersion time. The dominant mode of corrosion in under‐aged alloy is identified as localized pitting, while peak‐aged is highly susceptible to IGC in contrast extensive pitting corrosion is observed for over‐aged alloy. The observed differences in corrosion behavior are explained considering characteristics of precipitates. Formation of β (Mg2Si) in case of over‐aged alloy and presence of inclusions like AlFeMnSi particles are found to accelerate pitting corrosion.

Sticking-Free Reduction of Titanomagnetite Ironsand in a Fluidized Bed Reactor

Fluidized bed reduction of iron ore fines is typically inhibited by the onset of “sticking” at temperatures above 973 K, which leads to particle agglomeration and defluidization of the bed. Here, we report the sticking-free fluidized bed reduction of titanomagnetite (TTM) ironsand at 1223 K in Ar-H2 gas mixtures. We show that sticking is prevented by the formation of a protective titanium-rich oxide shell around each particle during the initial reduction stage. This protective shell prevents iron-iron contact between particles throughout the reduction process, enabling metallization degrees of 93 pct to be attained without sticking occurring. Phase evolution during the reaction has also been analyzed using q-X-ray diffraction and scanning electron microscope/energy dispersed spectroscopy. We find that the reduction proceeds through four separate stages. During the initial stage, approximately half of the initial TTM phase is converted to wustite, forming a network of sub-micron wustite channels which interlace the TTM matrix. During this stage, Ti and Al are enriched within the TTM matrix, due to the low solubility of both species in wustite. This enrichment stabilizes the remaining TTM, meaning that wustite is then preferentially reduced to metallic iron in stage 2 of the reduction. In stage 3, the remaining Ti-enriched TTM is reduced directly to metallic iron and ilmenite. The final stage of reduction involves the conversion of ilmenite into rutile and pseudobrookite. Our findings clarify the important role played by titanium species during the reduction of TTM and suggest that New Zealand ironsand can offer significant advantages over conventional hematite ores when used as a feedstock for fluidized bed direct-reduced iron processes.

Comparative Analysis of the Chemical Composition and Microstructure Conformation Between Different Dental Implant Bone Drills.

Background: Hardness is considered an important parameter for evaluating the clinical performance of dental implant bone drills. It is connected to the chemical composition, microstructure conformation and manufacture of the surgical drills. Methods: Microstructure of five dental implant drills using scanning electronic microscopy (SEM) integrated with energy dispersive X-ray spectrometry. Vickers microhardness was measured using a CV 2000 microhardness tester with an indentation force of 500 g. Results: Composition of the implant drills was typical of martensitic stainless steel (MSS). The drills contained 13%–17% of Cr; Mo, Si and Mn were present as minor ligands. The examined bone drills showed different external surface conformation and hardness in relation to the different industrial production processes. A rougher external surface and a higher hardness value are characteristics of the surgical bone drills produced by hot forming; the implant drills produced by machining showed mailing lines on their external surface and a lower hardness. Conclusions: Different compositions and treatments were used by the manufacturers to improve the hardness of the external layer of the dental implant drills making them prone to a diverse heat generation during the implant site preparation.