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(Cu-Zn-Ni) shape memory alloy with different percent have been prepared by using high frequency induction furnace under argon atmosphere. All of the specimens obtained from this alloys were heated in furnace for (15 minutes at 865°C) for homogenization and quenched in iced-water. Comparisons has been made with data obtained via differential scanning calorimetry (DSC) and energy-dispersive X-ray spectroscopy (EDS). The metallographic analyses were carried out by using optical microscopy (OM).

Series of alkali metal fluoroscandiates were prepared by reacting corresponding individual alkali fluorides MeF and ScF3 (were Me was Li, Na, K, Rb, Cs) at 400–600 °C for 100 h under argon atmosphere. The Me : Sc ratio varied from 1 : 1 to 3 : 1. X-ray powder diffraction analysis showed that the following phases were formed: Li3ScF6, Na3ScF6, NaScF4, K3ScF6, KSc2F7, Rb3ScF6, Cs3ScF6, CsScF4.

In the present study Ti-Al compounds formation in cold spray aluminium coatings on titanium alloy substrates by annealing in argon atmosphere at temperature in the range from 830 to 1270 K was considered. Experimental and modeling results of intermetallic compounds synthesis in cold spray coatings were presented. Formation of TiAl3 and Ti3Al phases was obtained. Data of X-ray, microstructure and microhardness analysis was shown.

The aim of this work was to study the effect of ball to powder weight ratio (BPR) on biodegradable binary magnesium-zinc (Mg-Zn) alloy synthesized using mechanical alloying. A powder mixture of Mg-5wt%Zn was milled in a planetary mill under argon atmosphere using a stainless steel container and balls. Milling process was carried out at 200 rpm for 5 hours using various BPR (i.e. 5:1, 10:1, 15:1, 20:1). Then, as milled powder was compacted under 400 MPa and sintered in a tube furnace at 300 °C in argon flow for an hour. The sintered density and microhardness of the alloy increased as BPR increased up to 15:1. However a further increasing showed a reduction in both density and microhardness which due to enlargement of crystallite and particle which resulted from the excessive internal energy during mechanical alloying.

The experimental studies were carried on for the test samples of welds of the steel 12X18H10T; the results are presented. The effect produced by the nanostructured modifying powders added to the weld pool on the quality of weld joints was examined. The weld joints were obtained by arc welding in argon atmosphere using consumable electrode. Due to the weld pool modification, the dendrite size was found to decrease and a more equilibrium microstructure would form in the weld material.

In this study, influence cobalt additives on the microstructural and hardness properties of an Al-Zn-Mg-Cu-Fe-Cr-Ni PM alloy undergone the retrogression and re-aging treatment were carried out. Green compacts pressed at 370 MPa were then sintered at temperature 650°C in argon atmosphere for two hours. The sintered compacts subjected to a homogenizing treated at 470°C for 1.5 hours then aged at 120°C for 24 hours and retrogressed at 180°C for 30 minutes, and then re-aged at 120°C for 24 hours. Microstructural results of the Al-Zn-Mg-Cu-Fe-Cr-Ni-Co alloys introduced an intermetallics compound in the matrix of alloy, identified as the Al5Co2, Al70Co20Ni10 and Al4Ni3 phases besides to the MgZn2 and Mg2Zn11 phases which produced of the precipitation hardening during heat treatment. These compounds with precipitates provided strengthening of dispersion that led to improved Vickers’s hardness and dinsifications properties of the alloy. The highest Vickers hardness of aluminum alloy containing cobalt was gotten a...

In present study, TaC−TaB2 nanocrystalline powder was produced by microwave synthesis. 3Ta and B4C Al as starting materials were milled for 1, 3, 6 and 9 h then pressed to form pellets. Green compacts were placed in a microwave oven with powder equal 1100W and argon atmosphere, for synthesis. The final products were studied by XRD and SEM analytical techniques. The results showed increasing of the milling time to 9 h the synthesis of desired phases (TaC and TaB2) was associated with greater success and the amount of the side products and intermediate compounds reach to minimum in the product. Also, with increasing of milling time from 1 to 9 h the required time for synthesis of samples reduces from 3 min to 35 sec. This method is an economical method for the preparation TaC−TaB2 powder with respect to energy, time and simplicity.

This paper reports the influence of the annealing in air and argon atmosphere on the structural and magnetic characteristics of Co-doped ZnO powders. XRD studies reveal a wurzite- type structure, while the formation of Co3O4 secondary phase was evidenced by Raman spectroscopy only for the sample annealed in air. A ferromagnetic behavior was observed for the sample annealed in air atmosphere and this behavior was explained. The sample annealed in argon atmosphere presents a paramagnetic behavior.

Herein we report lithographically fabricated FET with annealed graphene quantum dots (GQDs) as channel shows higher Ion/Ioff ratio as compared to as-prepared GQDs as channel. GQDs are synthesized via an electrochemical avenue using multiwall carbon nanotubes. As-prepared dots of 4.5 ± 0.55 nm average diameter are found to be p-type in air under ambient conditions with Ion/Ioff ratio of 45 and after annealing in Argon atmosphere at 300°C for 20 min it shows ambipolar nature with significant increase in resistance with Ion/Ioff ratio of 200.

Smooth, transparent and highly oriented nanostructured ZnO films were synthesized by RF‐magnetron sputtering onto Si(100) substrates. A mild‐pressed zinc oxide powder target was used for all depositions. The sputtering parameters were varied in order to obtain structures with good adherence and crystallinity. The depositions were carried out in inert argon atmosphere at four sputtering pressures (0.2 Pa, 0.25 Pa, 0.3 Pa and 0.45 Pa). ZnO films were deposited at 150 °C. The films were characterized from structural (XRD) and morphological (AFM) point of view. The influence of each sputtering parameter on the morphological and structural properties is discussed.

Pure and Cu doped SnO2 nanowires and nanobelts were grown in a tubular furnace under argon atmosphere at ambient pressure. X‐ray diffraction showed that Cu gets incorporated into the SnO2 lattice. Isolated single nanowire sensors have been fabricated for detection of H2S gas at room temperature. Cu doping was found to reduce the sensitivity of these sensors in contrast to results reported for Cu doped SnO2 thin films. Photoluminescence studies indicate that the reduction is sensitivity may be due to reduced defect density.

Growth of Nd:YAG single crystals by the Czochralski method in an argon atmosphere with ADC (Automatic Diameter Control) r.f. heating was investigated. The conditions required to grow Nd:YAG single crystals are described. The relationship of the latter to the growth mechanism is discussed and a mechanism proposed which provides an explanation of the manner in which the crystals grow and reject impurities. The Nd:YAG single crystal with growth direction of 〈111〉 was produced by effective control of growth conditions.

Small, sealed Cu freezing cells (100 mm high and 27.5 mm diameter) were fabricated for use in calibrating thermocouples in industry. The cell volume was about 15.8 cm3 and contained about 125 g of Cu. These cells can be used to calibrate a thermocouple of 5.5 mm diameter. The cells were sealed in an argon atmosphere so as to be at a pressure of 1 atmosphere at the freezing temperature. The cells were tested with a Pt/Pd‐thermocouple as a reference thermometer and compared with a large, standard Cu freezing cell. The small cells showed a slightly lower temperature than the standard cell. The uncertainty of the cell temperature was calculated to be 0.1 °C within a confidence range of 95 %.