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Volume 16, Issue 1
Displaying 1-5 of 5 articles from this issue
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[in Japanese]1969 Volume 16 Issue 1 Pages 1-11
Published: March 25, 1969
Released on J-STAGE: May 22, 2009
JOURNAL OPEN ACCESSDownload PDF (1799K) -
Toranosuke Kawaguchi, Hiroshi Yamamoto1969 Volume 16 Issue 1 Pages 12-22
Published: March 25, 1969
Released on J-STAGE: December 04, 2009
JOURNAL OPEN ACCESSThis experiment was carried out to produce Fe-Si-Al ternary alloys by means of powdertype spraying method, and some properties of the sheets produced under the various spraying conditions of spraying were examined. Audio-heads were made from both sprayed Fe-Si-Al ternary alloy sheets and laminated sheets of Fe-Si-Al ternary alloy and copper. Of course, such materials were produced under the optimum spraying condition based on the previous experimental result, and the audio-head characteristics were measured.
The results obtained.are as follows: (1) Oxygen-hydrogen flame for Fe-Si-Al ternary alloy powder spraying is more suitable than oxygen-acetylene gas. (2) Flame sealing by nitorogen on argon gas is not so effective in improving the magnetic properties. (3) Magnetic properties depend on the spraying distance. In this process, the distance of 8-12cm gave the best results. (4) Chemical analysis of the sprayed Fe-Si-Al alloy sheet showed that 0.2-0.3wt% o of silicon and aluminium were lost irrespective of the spraying distance. (5) Line patterns by X ray micro analyser of the product showed that aluminium is too much enriched locally as compared with the original powder content.
Sudh aluminium may be in metallic or oxidized state. (6) Record-play back frequency characteristics of heads made from the sprayed Fe-Si-Al ternary alloy sheet are superior to those from laminated permalloy plates.View full abstractDownload PDF (9736K) -
Hiroshi Yamamoto1969 Volume 16 Issue 1 Pages 23-28
Published: March 25, 1969
Released on J-STAGE: May 22, 2009
JOURNAL OPEN ACCESSThere are many methods for measuring surface area of powders, and among them gas adsorption method(BET-method) is the best in reliance. However, "BET-method" has two weak points, one is taking comparably long time (few hours or more) to measure equiliblium pressure of the adsorption, and the other is passing through complicated calculations to get the value of surface area from the value of equiliblium pressure.
In this study "one point method" was applied to avoid a long measuring time required to get the equiliblium pressure, and a correction method was studied for inevitable error containing in "one point method".
A calculating-diagram (surface area vs. equiliblium pressure) was drawn to. abridge the complicated calculations. In this process, several factors concerned with experimental conditions were fixed as constants. However, actual measurements had given slight deviations with these factors from the fixed values, therefore some corrections were made.
The simplified procedure above mentioned needs only an hour or less for measurement, and gave a value with a deviation only less than ±5% from that by the normal BET-method.View full abstractDownload PDF (357K) -
Fabrication Study of High Density Sintered UO2 PelletsMunetsugu Makino1969 Volume 16 Issue 1 Pages 29-37
Published: March 25, 1969
Released on J-STAGE: December 04, 2009
JOURNAL OPEN ACCESSSintered UO2 pellets of high densities are used as fuel for water-cooled reactors. Relations between physical properties … such as bulk density, tap density, specific surface area, average particle size and compatibilities or sinterabilities of as-received, oxidation-reduction treated or ball-milled powders were examined. In these experiments, powders were compacted at 2-7 t/cm2 and were sintered for 1-10 hours at temperatures from 1400°C to 1650°C in an atmosphere of cracked ammonia.
The results are summarized below :
1) The specific surface areas of UO2 powders increased with increasing oxidation-reduction cycles ; however only small change was observed in the ball-milled UO2 powders.
2) In contrast to the ball-milled UO2 powder, the green density of the oxidation-reduction treated UO2 decreased with increasing specific surface area. Ball-milling and oxidation-reduction treatment improved the sinterability.
3) The activation energy of the densification of UO2 during sintering in cracked ammonia was calculated.
4) It was found that the densification factors are proportional to the specific surface area of as-received or activation treated powders.View full abstractDownload PDF (2011K) -
The Variation of Lattice Parameter with Carbon Content of TaC-WC Solid Solution in High Carbon RangeTakeji Hachisuka1969 Volume 16 Issue 1 Pages 38-41
Published: March 25, 1969
Released on J-STAGE: December 04, 2009
JOURNAL OPEN ACCESSTaC-WC solid solutions in high carbon range, containing up to 30 mol % WC, were prepared by heating single carbide mixtures in vacuum. And the variations of lattice parameter with carbon content were studied. The results are as follows.
1) The lattice parameter of TaC-WC solid solutions increased linearly with carbon content.
2) Fitted equations of these solid solutions were obtained by applying the least-squares as follows.
(Ta0.9W0.1)C:a0=4.337+0.101X
(Ta0.8W0.2)C:a0=4.311+0.116X
(Ta0.7W0.3)C:a0=4.328+0.085X X=C/(Ta+W)
3) The slopes of these equations are smaller than that of TaC obtained by other investigators. But the recalculated value of the slope employing Bowman's results in high carbon range agreed with the values of solid solutions within the range of experimental errors.View full abstractDownload PDF (250K)
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