Effect of Surface Oxidization on the Spectral Normal Emissivity of Aluminum 3A21 at the Wavelength of 1.5  $$\upmu $$ μ m Over the Temperature Range from 800 K to 910 K

AbstractThis work presents an application of the subsecond calorimetry technique at very high temperatures, which uses both contact and radiance temperature measurements. This technique is normally applied for thermophysical characterization of high temperature solid phase materials in the temperature range from ambient up to about 2600 K, which is the limit of the standard tungsten-rhenium thermocouple use. Simultaneously with contact temperature measurements, noncontact or radiance temperature detection may be performed in the approximate range from 1000 to 2600 K in order to acquire information on spectral normal emissivity of specimen under test. In this study, however, the specimen is heated above 2600 K and, then, the temperature is measured only by the noncontact mean. In the extended temperature range, the obtained values of the spectral normal emissivity are extrapolated for each experimental run, which makes possible a conversion from radiance to absolute specimen temperature. In order to test this application, a pure polycrystalline specimen of tungsten in the form of rod, 3 mm in diameter and 200 mm in length, has been used. The specimen has been heated in vacuum environment of about 10–4 mbar by short pulses of high DC current with a gradual increase of the total heating time from about 0.5–2.5 s. During the specimen heating and the beginning of the cooling period, four sets of experimental data have been recorded and reduced by using the corresponding data reduction procedure. Obtained results of specific heat and specific electrical resistivity from ambient to 3700 K, total hemispherical emissivity from 1000 to 3700 K and spectral normal emissivity from 1000 to 2600 K (extrapolated to 3700 K) are presented, discussed and compared with related literature data.

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Effect of Surface Oxidization on the Normal Spectral Emissivity of Straight Carbon Steel at 800–1100 K in Air

ISIJ International ◽

10.2355/isijinternational.55.697 ◽

2015 ◽

Vol 55 (3) ◽

pp. 697-705 ◽

Cited By ~ 7

Author(s):

Deheng Shi ◽

Fenghui Zou ◽

Zunlue Zhu ◽

Jinfeng Sun

Keyword(s):

Carbon Steel ◽

Spectral Emissivity ◽

Normal Spectral Emissivity ◽

Effect Of Surface ◽

Surface Oxidization

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Defects in ion implanted silicon

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100109070 ◽

1978 ◽

Vol 36 (1) ◽

pp. 386-387

Author(s):

J.A. Lambert ◽

P.S. Dobson

Keyword(s):

Defect Structure ◽

Dislocation Loops ◽

Frank Loop ◽

Burgers Vector ◽

Temperature Range ◽

Perfect Dislocation ◽

Contrast Analysis ◽

Image Position ◽

Ion Implanted

The defect structure of ion-implanted silicon, which has been annealed in the temperature range 800°C-1100°C, consists of extrinsic Frank faulted loops and perfect dislocation loops, together with‘rod like’ defects elongated along <110> directions. Various structures have been suggested for the elongated defects and it was argued that an extrinsically faulted Frank loop could undergo partial shear to yield an intrinsically faulted defect having a Burgers vector of 1/6 <411>.This defect has been observed in boron implanted silicon (1015 B+ cm-2 40KeV) and a detailed contrast analysis has confirmed the proposed structure.

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Domain coarsening by grain boundary migration in ordered Ni4Mo

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100144279 ◽

1986 ◽

Vol 44 ◽

pp. 560-561

Author(s):

K. Vasudevan ◽

H. P. Kao ◽

C. R. Brooks ◽

E. E. Stansbury

Keyword(s):

Grain Boundary ◽

Grain Boundaries ◽

Short Range ◽

Boundary Migration ◽

Grain Boundary Migration ◽

Rapid Cooling ◽

Temperature Range ◽

Fee Structure ◽

Domain Coarsening ◽

Boundary Reaction

The Ni4Mo alloy has a short-range ordered fee structure (α) above 868°C, but transforms below this temperature to an ordered bet structure (β) by rearrangement of atoms on the fee lattice. The disordered α, retained by rapid cooling, can be ordered by appropriate aging below 868°C. Initially, very fine β domains in six different but crystallographically related variants form and grow in size on further aging. However, in the temperature range 600-775°C, a coarsening reaction begins at the former α grain boundaries and the alloy also coarsens by this mechanism. The purpose of this paper is to report on TEM observations showing the characteristics of this grain boundary reaction.

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Nucleation and initial growth of Pd2Si crystals on Si(111)

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100150058 ◽

1993 ◽

Vol 51 ◽

pp. 844-845

Author(s):

Xianghong Tong ◽

Oliver Pohland ◽

J. Murray Gibson

Keyword(s):

High Vacuum ◽

Dark Field ◽

Ultra High Vacuum ◽

Initial Growth ◽

Surface And Interface ◽

Dark Field Imaging ◽

Transmission Electron ◽

Initial Stage ◽

Effect Of Surface

The nucleation and initial stage of Pd2Si crystals on Si(111) surface is studied in situ using an Ultra-High Vacuum (UHV) Transmission Electron Microscope (TEM). A modified JEOL 200CX TEM is used for the study. The Si(111) sample is prepared by chemical thinning and is cleaned inside the UHV chamber with base pressure of 1x10−9 τ. A Pd film of 20 Å thick is deposited on to the Si(111) sample in situ using a built-in mini evaporator. This room temperature deposited Pd film is thermally annealed subsequently to form Pd2Si crystals. Surface sensitive dark field imaging is used for the study to reveal the effect of surface and interface steps.The initial growth of the Pd2Si has three stages: nucleation, growth of the nuclei and coalescence of the nuclei. Our experiments shows that the nucleation of the Pd2Si crystal occurs randomly and almost instantaneously on the terraces upon thermal annealing or electron irradiation.

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The reaction of amorphous Ni-Nb films with Si in the presence of a native SiO2 layer

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100176459 ◽

1990 ◽

Vol 48 (4) ◽

pp. 664-665

Author(s):

N. Rozhanski ◽

A. Barg

Keyword(s):

High Temperature ◽

Crystallization Temperature ◽

Diffusion Barriers ◽

Sio2 Layer ◽

Si Substrate ◽

Cross Sectional ◽

Plan View ◽

Temperature Range ◽

Sputter Deposited

Amorphous Ni-Nb alloys are of potential interest as diffusion barriers for high temperature metallization for VLSI. In the present work amorphous Ni-Nb films were sputter deposited on Si(100) and their interaction with a substrate was studied in the temperature range (200-700)°C. The crystallization of films was observed on the plan-view specimens heated in-situ in Philips-400ST microscope. Cross-sectional objects were prepared to study the structure of interfaces.The crystallization temperature of Ni5 0 Ni5 0 and Ni8 0 Nb2 0 films was found to be equal to 675°C and 525°C correspondingly. The crystallization of Ni5 0 Ni5 0 films is followed by the formation of Ni6Nb7 and Ni3Nb nucleus. Ni8 0Nb2 0 films crystallise with the formation of Ni and Ni3Nb crystals. No interaction of both films with Si substrate was observed on plan-view specimens up to 700°C, that is due to the barrier action of the native SiO2 layer.

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A Transmission Electron Microscopical Investigation of Phase Transformations in TiNi

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s1431927600001446 ◽

1980 ◽

Vol 38 ◽

pp. 340-341

Author(s):

P. Moine ◽

G. M. Michal ◽

R. Sinclair

Keyword(s):

Electron Microscopy ◽

Phase Transformations ◽

Applied Stress ◽

Structural Changes ◽

Microscopical Investigation ◽

Temperature Range ◽

Transmission Electron ◽

Electron Microscopical ◽

Diffraction Effects ◽

Microscopy Images

Premartensitic effects in near equiatomic TiNi have been pointed out by several authors(1-5). These include anomalous contrast in electron microscopy images (mottling, striations, etc. ),diffraction effects(diffuse streaks, extra reflections, etc.), a resistivity peak above Ms (temperature at which a perceptible amount of martensite is formed without applied stress). However the structural changes occuring in this temperature range are not well understood. The purpose of this study is to clarify these phenomena.

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