High Frequency Furnace Research Articles

Influence of Zirconium on the Corrosion Passivation of Titanium in Simulated Body Fluid

Pure Ti and 85%Ti-15%Zr alloy were sintered in a heat induction high frequency furnace. The corrosion behaviour of Ti and 85%Ti-15%Zr in simulated body fluid (SBF) was studied. The work was achieved using different techniques as the cyclic polarization (PCP), the impedance spectroscopy (EIS), and the change of the potentiostatic current with time (PCT) experiments. The morphology of the surfaces of Ti and Ti-Zr after being corroded in SBF for 72 were investigated by a scanning electron microscope (SEM) and the analysis for the layer formed on that surface was collected via energy dispersive X-ray (EDX). Results depicted that the 15% Zr present within Ti decreases the corrosion via increasing Ti corrosion resistance and minimizing its measured corrosion rate. PCP data proved that the addition of Zr reduced all anodic, cathodic and corrosion currents. EIS results confirmed that Zr has a positive impact on the reduction of corrosion resistance. PCT, SEM, and EDX examinations displayed that both Ti and Ti-Zr alloy don’t show pitting corrosion even after 72 h exposure to SBF.

Superstructure formation in the solid solution Sc3Pt3−xIn3 (x = 0–0.93)

Abstract The equiatomic indide ScPtIn (ZrNiAl type, space group P 6 ‾ $‾{6}$ 2m) shows an extended solid solution Sc3Pt3–xIn3. Several samples of the Sc3Pt3–xIn3 series were synthesized from the elements by arc-melting and subsequent annealing, or directly in a high frequency furnace. The lowest platinum content was observed for Sc3Pt2.072(3)In3. All samples were characterized by powder X-ray diffraction and their lattice parameters and several single crystals were studied on the basis of precise single crystal X-ray diffractometer data. The correct platinum occupancy parameters were refined from the diffraction data. Decreasing platinum content leads to decreasing a and c lattice parameters. Satellite reflections were observed for the Sc3Pt3–xIn3 crystals with x = 0.31–0.83. These satellite reflections could be described with a modulation vector ( 1 3 , 1 3 , γ ) $\left(\frac{1}{3},\frac{1}{3},\gamma \right)$ ( γ = 1 2 $\gamma =\frac{1}{2}$ c* for all crystals) and are compatible with trigonal symmetry. The interplay of platinum filled vs. empty In6 trigonal prisms is discussed for an approximant structure with space group P3m1.

Study on Phase Transformation and Desulfurization Ability during Refining with Flux Additions of B2O3 and CaF2 into CaO-Based Desulfurizer

CaF2 aids melting and desulfurization, but can also cause environmental pollution. Thus, it has become important to discuss the phase transformation and find a substitute for CaF2. A CaO-based desulfurizer with various flux additions of B2O3 and CaF2 is investigated during the refining process. The purpose of this study is to discuss the phase transformation and desulfurization ability and during refining with B2O3 and CaF2 using a high frequency furnace. Experimental results indicate that the melting temperature of CaO-Al2O3-SiO2 series desulfurizer becomes lower when more B2O3 and less CaF2 are added. On the other hand, the desulfurization ability can be affected within 15 min when various proportions of B2O3 and CaF2 areadded. The desulfurization ability is better with a high content of B2O3 desulfurizer within a 15 min period. However, the desulfurization ability is not affected by the proportion of B2O3 and CaF2 for a long melting period (30 min).

Release and Transformation Characteristics of Arsenic during Coal Pyrolysis and Gasification

Pyrolysis and gasification experiments of bituminous coal (Yunnan Zhenxiong) have been conducted in a high frequency furnace reactor to investigate the distinction of release and transformation of arsenic at two different stages decoupled from integrated gasification. The results indicate that the release rate of arsenic changes significantly with increasing temperature and holding time during gasification when compared with pyrolysis. Escape of volatiles accounts for the release of arsenic during pyrolysis, while the promotion of migration during gasification is attributed to the carbon conversion and minerals melting. Arsenic in char derived from pyrolysis and gasification mainly presents as forms bound to residues and sulfides, and fraction of extractable form of arsenic from gasified char is higher than that from pyrolysis char.

SrPt2Al2 – A (3+2)D-incommensurately modulated variant of the CaBe2Ge2 type structure

Abstract The first ternary compound in the Sr–Pt–Al system, SrPt2Al2, was synthesized by melting of the elements in a sealed niobium tube in a high frequency furnace. The structure of SrPt2Al2 was determined by single-crystal X-ray diffraction on the basis of data sets recorded at 90, 150, 210, 270 and 300 K. The compound crystallizes in an incommensurately modulated (3+2)D structure being related to the tetragonal primitive CaBe2Ge2 type structure. The structure was refined in the orthorhombic superspace group Pmmn(α,0,0)0s0(0,β,0)s00 (α=0.222(1) a*, β=0.224(1) b*, a=b=436.89(5), c=1010.16(13) pm at 90 K) with R M=0.0403, R S,1=0.0597 and R S,2=0.2046. The structural relation with CaBe2Ge2 along with a refinement in the tetragonal superspace group P4/nmm(α,0,0)0000(0,α,0)00s0 is discussed with respect to the temperature dependence of the q-vectors and by group-subgroup relations. The modulation, from the standpoint of the crystal chemistry, is mainly caused by the distortion of the Pt arrangements within the pseudo-tetragonal ab plane.

ChemInform Abstract: Segregation of Cd2 Pairs in CaCu9Cd2 and EuCu9Cd2.

AbstractCaCu9Cd2 and EuCu9.14Cd1.86 are synthesized by solid state reaction of stoichiometric mixtures of the elements (argon, Ta tubes, high frequency furnace; 1.

ChemInform Abstract: EuLiGe2 and YbLiGe2 — A Divalent and an Intermediate‐Valent Compound with CaLiSi2‐Type Structures.

AbstractThe title compounds are synthesized from stoichiometric mixtures of the elements (Ta tubes, 1173 K; high frequency furnace).

ChemInform Abstract: Yb4LiGe4 — A Yb Mixed Valent Zintl Phase with Strong Electronic Correlations.

AbstractYb4LiGe4 and Yb5Ge4 are prepared from the elements in stoichiometric ratios (high frequency furnace, Ta ampules, 1070 K, 20 min).

Synthesis, structure and properties of Nd2BC containing the trans-dibora–(1,3)-butadiene [C=B–B=C]8–-unit

Abstract The crystal structure of Nd2BC, synthesized by arc melting of the element mixture, repeated in a high frequency furnace and subsequent annealing at 1070 K, has been determined from single crystal X-ray diffraction data. It crystallizes in a new structure type in the monoclinic space group C2/m (a = 12.732(2) Å, b = 3.6848(4) Å, c = 9.398(2) Å, β = 130.43(1)°, R1 = 0.038 (wR2 = 0.091) for 596 reflections with I o > 2σ (I o)). Characteristic building units are C—B—B—C entities with the distances d C—B = 1.51(2) Å and d B—B = 1.65(2) Å. These units are embedded in a framework of neodymium atoms resulting from the stacking of slightly corrugated two-dimensional square nets of Nd. Within the ionic limit Nd2BC can be described as (Nd2+)4[C—B—B—C]8– or (Nd3+)4[CBBC]8– · 4 e– with [C=B—B=C]8– units, which are isoelectronic to 1,3-butadiene. The measured magnetic moment of 3.65μ B per Nd atom in Nd2BC is in good agreement with the expected value of 3.62μ B for 4f3 configuration. LMTO band structure calculations show that Nd2BC is metallic and the extra electrons occupy mainly bonding Nd-5d and antibonding π* states within the C—B—B—C units.

Pilot plant study of nozzle clogging mechanisms during casting of REM treated stainless steels

A pilot scale bottom teemed high frequency furnace with a nominal capacity of 600 kg and an adjustable nozzle temperature was used to study clogging of rare earth metal (REM) treated stainless steels. The influence of the following variables on the clogging was studied: amount of REM, fraction of oxide clusters, total oxygen content in the steel, reoxidation, aluminium additions before REM additions and silicon additions during casting. Overall, the results show that, during the present experimental conditions, mainly two typical clogging rates could be identified, fast and slow clogging. Two main differences could be detected between the fast and slow clogging rates. Steel containing mainly small single inclusions clogged faster than steel containing mainly large inclusion clusters. The reason was believed to be that the small inclusions could stick to the nozzle wall at narrow passages where the steel flow velocity was high while the larger ones could not. The source of the small inclusions was believed to be reoxidation. It was also found that the main part of the nozzle accretion was caused by agglomeration of inclusions and inclusion clusters, while only a thin oxide film along the nozzle wall was caused by oxide precipitation at the nozzle wall.

Synthesis of Single‐Walled Carbon Nanotubes in a High Frequency Furnace

AbstractAn alternative method for the synthesis of single‐walled carbon nanotubes (SWCNTs) is presented, which is based on the co‐evaporation of a pure graphite body and a metal catalyst (nickel). The graphite body is inductively heated in a high frequency furnace up to ~2400 °C. Characterization of the produced soot was performed using SEM, TEM and Raman spectroscopy techniques.

Rare Earth-rich Cadmium Compounds RE23T7Cd4 (T = Co, Ni, Ru, Rh, Ir, Pt)

The rare earth-rich intermetallic compounds RE23T7CD4(RE = La-Nd, Sm, Gd, Tb; T = Co, Ni, Ru, Rh, Ir, Pt) were synthesized by melting of the elements in sealed tantalum tubes in a high frequency furnace. They crystallize with the Pr23Ir7Mg4-type structure, space group P63mc, Z = 2. The structures of La23Pt7Cd4 (a = 1025.4(2), c = 2319.5(5) pm, wR2 = 0.0425, 2587 F2, 74 variables), La23Ru6.87(1)Cd4 (a = 1015.0(2), c = 2282.8(4) pm, wR2 = 0.0383, 2459 F2, 75 variables), and Nd23Rh7Cd4 (a = 990.0(2), c = 2239.0(5) pm, wR2 = 0.0507, 2350 F2, 74 variables) were refined from single crystal X-ray diffractometer data. Central structural motifs of the RE23 T7Cd4 compounds are transition metal-centered trigonal prisms of rare earth atoms and Cd4 tetrahedra. The RE6T prisms are condensed via common edges and corners, leading to three-dimensional networks. Typical interatomic distances in the prismatic network and in the Cd4 tetrahedra are 295 - 313 pm La-Pt and 319 - 325 pm Cd-Cd, respectively (examplarily for La23Pt7Cd4)

Rare Earth-rich Cadmium Compounds RE4TCd (T = Ni, Pd, Ir, Pt)

New intermetallic compounds RE4TCd (RE = Y, La-Nd, Sm, Gd-Tm, Lu; T = Ni, Pd, Ir, Pt) were synthesized by melting of the elements in sealed tantalum tubes in a highfrequency furnace. They crystallize with the Gd4RhIn-type structure, space group F 4̄3m, Z = 16. The four gadolinium compounds were characterized by single crystal X-ray diffractometer data: a = 1361.7(1) pm, wR2 = 0.062, 456 F2 values, 19 variables for Gd4NiCd; a = 1382.1(2) pm, wR2 = 0.077, 451 F2 values, 19 variables for Gd4PdCd; a = 1363.6(2) pm, wR2 = 0.045, 494 F2 values, 19 variables for Gd4IrCd; a = 1379.0(1) pm, wR2 = 0.045, 448 F2 values, 19 variables for Gd4PtCd. The rare earth atoms build up transition metal-centered trigonal prisms which are condensed via common corners and edges, leading to three-dimensional adamantane-related networks. The cadmium atoms form Cd4 tetrahedra which fill voids left in the prisms’ network.

Non-Collinear Magnetic Structure of TbB4

Non-Collinear Magnetic Structure of TbB₄

Ferromagnetic Ordering in the Thallide EuPdTl2

Abstract The new thallide EuPdTl2, synthesized from the elements in a sealed tantalum tube in a highfrequency furnace, was investigated by X-ray diffraction on powders and single crystals: MgCuAl2 type, Cmcm, Z = 4, a = 446.6(1), b = 1076.7(2), c = 812.0(2) pm, wR2 = 0.0632, 336 F2 values, 16 variables. The structure can be considered as an orthorhombically distorted, palladium-filled variant of the binary Zintl phase EuTl2. The palladium and thallium atoms build up a three-dimensional [PdTl2] polyanion with significant Pd-Tl (286 - 287 pm) and Tl-Tl (323 - 329 pm) interactions. The europium atoms fill distorted hexagonal channels of the [PdTl2] polyanion. Susceptibility measurements show a magnetic moment of 7.46(5) μB/Eu atom, indicative of divalent europium. EuPdTl2 is a soft ferromagnet with a Curie temperature of TC = 12.5(5) K.

Synthesis and Structural Relationship of the Ternary Indides Sc3Ni2.10(5)In3.60(5), Sc3Ni2.14(2)In3.76(2), ScPd0.981(2)In and Sc3Rh1.594(9)In4

The ternary scandium transition metal indides Sc3Ni2.10(5)In3.60(5), Sc3 Ni2.14(2)In3.76(2), ScPd0.981(2)In, and Sc3Rh1.594(9)In4 have been synthesized from the elements in glassy carbon crucibles in a high frequency furnace or by arc-melting. They have been investigated by X-ray powder diffraction and the structures refined on the basis of single crystal diffractometer data: Lu3Co1.87In4 type, P6̄, a = 745.7(1), c = 342.85(7) pm, wR2 = 0.0689, 545 F2, 24 parameters for Sc3Ni2.10(5)In3.60(5), a = 753.63(7), c = 344.3(1) pm, wR2 = 0.0362, 792 F2, 22 parameters for Sc3Ni2.14(2)In3.76(2), P6̄2m, ZrNiAl type, a = 764.1(2), c = 345.90(8) pm, wR2 = 0.0333, 326 F2, 15 parameters for ScPd0.981(2)In, and P6̄, a = 769.4(1), c = 684.1(1) pm, wR2 = 0.0526, 1097 F2, 35 parameters for the new structure type Sc3Rh1.594(9)In4. In the three structure types the scandium atoms build trigonal prisms. The latter are filled exclusively by palladium atoms in ScPd0.981(2)In, while transition metal and indium atoms fill these sites in the other three structures. The different coloring of the trigonal prismatic sites leads to a symmetry reduction for the structures of Sc3Ni2.10(5)In3.76(5), Sc3Ni2.14(2)In3.76(2) and Sc3Rh1.594(9)In4. The structural relationship is described on the basis of a group-subgroup scheme. Chemical bonding in these intermetallics is briefly discussed.

A 119Sn and 151Eu Mössbauer spectroscopic, magnetic susceptibility, and electrical conductivity investigation of the stannides EuTSn (T = Cu, Pd, Ag, Pt)

The title compounds were prepared from the elements by reaction in sealed tantalum tubes in a high frequency furnace. EuCuSn and EuAgSn crystallize with the KHg2 type structure with a statistical distribution of the copper (silver) and tin atoms on the mercury position. EuPdSn and EuPtSn adopt the TiNiSi type structure, a ternary ordered version of KHg2. The four stannides show Curie–Weiss behaviour above 60 K with experimental magnetic moments between 7.75(5) and 8.10(5) µB/Eu indicating divalent europium. While EuCuSn remains paramagnetic down to 4.2 K, antiferromagnetic ordering is observed for EuAgSn, EuPdSn and EuPtSn with Néel temperatures of 6.0(5), 15.5(5) and 28.5(5) K, respectively. EuPdSn and EuPtSn show metamagnetic transitions at fields of 2.5(2) and 0.8(1) T, respectively. The stannides EuCuSn, EuPdSn, EuAgSn and EuPtSn are metallic conductors. Temperature dependent 151Eu and 119Sn Mössbauer spectroscopic data confirm the magnetic transition temperatures and yield values of the internal (and transferred) magnetic flux densities. A compilation of the 151Eu isomer shifts for the whole series of EuTX (T = transition metal; X = element of the 3rd, 4th or 5th main group) compounds reveals an interesting linear correlation with the electron count.

Establishment of Efficient Operation Method for Small Capacity High Frequency Furnace

Establishment of Efficient Operation Method for Small Capacity High Frequency Furnace

The Crystal Structure and Chemical Properties of U2Al3C4 and Structure Refinement of Al4C3

A well crystallized sample of U2Al3C4 was obtained by melting the elemental components in a carbon crucible in a high frequency furnace. The crystal structure of this compound was determined from single-crystal diffractometer data of a twinned crystal: P63mc, a = 342.2(1) pm. c = 2323.0(3) pm. Z = 2 , R = 0.030 for 537 structure factors and 18 variable parameters. The structure can also be described in the higher symmetry space group P63/mmc with one split aluminum position. It consists of close packed layers of uranium and aluminum atoms with carbon atoms at interstitial sites. The structure is closely related to that of Al4C3, which was refined from single-crystal X-ray data to a residual of R = 0.033 for 135 F-values and 11 variables. The hydrolysis of U2Al3C4 with diluted hydrochloric acid resulted in about 74 (wt-)% methane, 8% ethane and ethylene, and 18% saturated and unsaturated higher hydrocarbons.

The HEVA Experimental Program

Between 1983 and 1989, the Fuel Behavior Studies Branch of the Commissariat a l'Energie Atomique-Grenoble performed eight tests in the HEVA (helium and vapor) program. This program, which is a part of the general French Institute for Nuclear Protection and Safety program concerning severe accident studies, is devoted to the measurement of fission product (FP) release rates under severe accident conditions. Each test was performed with a small section (three pellets) of a standard pressurized water reactor fuel rod in its original cladding, heated in a high frequency furnace, at temperatures up to 2,300 K, in a stream and hydrogen environment. The volatile FP release rates were measured by gamma spectrometry. Posttest examinations supplied further information about the behavior of the FP, mainly concerning the aerosol sizing and the chemical speciation of the deposits. The results were compared with those obtained by other laboratories and with the calculated values. The measured release rates are generally lower than those calculated using the CORSOR model. A large influence of the environment is evidenced. The aerosol mean aerodynamic diameter is [approximately] 0.3 [mu]m. The HEVA program is extended by the VERCORS program mainly devoted to low volatile FP release rates and kinetics.