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Volume 29, Issue 1
Displaying 1-6 of 6 articles from this issue
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[in Japanese]1982 Volume 29 Issue 1 Pages 1-7
Published: January 25, 1982
Released on J-STAGE: May 22, 2009
JOURNAL OPEN ACCESSDownload PDF (1837K) -
Densification and Effect of Heating Rate in α-Fe2O3Takeshi Nomura, Takashi Yamaguchi1982 Volume 29 Issue 1 Pages 8-12
Published: January 25, 1982
Released on J-STAGE: May 22, 2009
JOURNAL OPEN ACCESSDensification behavior of three representative a-Fe2O3 powders, which were chosen referring to the results of previous works, has been studied. Incorporation of plastic powder into powder compacts revealed that there exists a critical pore size which determines the final density. Effect of ball-milling of aggregated powder on sintering has been interpreted in terms of the behavior of intra-aggregate pores. Rate of heating has little effect on the densification but influences the grain growth.View full abstractDownload PDF (3033K) -
Effect of α-Fe2O3 Raw Material Powders on the Sintering of ZnFe2O4Takeshi Nomura, Takashi Yamaguchi1982 Volume 29 Issue 1 Pages 13-17
Published: January 25, 1982
Released on J-STAGE: May 22, 2009
JOURNAL OPEN ACCESSAs a final report of this program, effects of a-Fe2O3 raw material powders on the formation and sintering of ZnFe2O4 have been studied. It is shown that the ferrite formation is not a simple function of primary particle size of α-Fe2O3. Densification behavior of ZnFe2O4 is well correlated to that of corresponding α-Fe2O3 powders. The temperature at which the initial shrinkage starts is a function of primary particle size of ZnFe2O4, as is the case in α-Fe2O3. It is suggested that higher calcination temperatures are favorable for obtaining uniform microstructures.View full abstractDownload PDF (3750K) -
Hideshi Miura, Yoshiaki Itou, Youichi Tokunaga1982 Volume 29 Issue 1 Pages 18-24
Published: January 25, 1982
Released on J-STAGE: May 22, 2009
JOURNAL OPEN ACCESSDamping capacity is a very sensitive character of the internal structure as is clearly evidenced by the damping changes that occur when the shape of graphite in cast iron is altered. However, a limited amount of work has been carried out on the damping of sintered irons.
In this paper, the characteristics of the damping capacity of sintered irons are investigated and some factors affecting it are discussed by observing the micro-structure of the specimens. The damping capacity was measured by the transverse-vibration method at strain-amplitudes ranging from 2×10-6 to 1×10-4.
The results obtained were as follows: The damping capacity observed on a sintered iron can be separated into two parts; the amplitude independent part (QL-1) and the amplitude dependent part (QH-1). Magni-tude of QL-1 decreases with an increase of the density, sintering temperature and time, and it corresponds to the degree of sintering. QH-1 showes a well-defined amplitude dependence, that is, it increases linearly with the strain-amplitude. The origin of QH-1 is due mainly to the magneto-mechanical static hysteresis in ferrite. A specimen machined by grinding or repressed exhibits as high damping capacity as flaky cast iron. This may be caused by the existence of some elongated pores produced by machining.View full abstractDownload PDF (2969K) -
Hisashi Suzuki, Yasuro Taniguchi, [in Japanese]1982 Volume 29 Issue 1 Pages 25-29
Published: January 25, 1982
Released on J-STAGE: May 22, 2009
JOURNAL OPEN ACCESSEffect of nitrogen addition on some basic properties of WC-β-Co (β; WC-TiC solid solution) alloy was studied. Effect of tantalum carbide addition on the mechanical properties of nitrogen free or contained WC-β-Co alloy was also studied.
It was found that the grain size of carbonitride in the nitrogen contained WC-β-Co alloy became finer almost independently of TaC addition; the strength of those alloys was somewhat lowered by the poreformation caused by denitrification; however, the strength of hot-isostatically pressed alloy was extraordinarily increased; the hardness of alloys inclined to decrease to some extent. The three-phase region of the nitrogen contained WC-β-Co alloy was examined.View full abstractDownload PDF (1649K) -
Hiroshi Kawabata, Yoshio Fujimura, Eiichi Sentoku1982 Volume 29 Issue 1 Pages 30-34
Published: January 25, 1982
Released on J-STAGE: May 22, 2009
JOURNAL OPEN ACCESSThe purpose of this work is to analyze cermet tools by using EPMA, which is a simpler and a more economical method, and to estimate their cutting performance.
First, the examination was made to confirm the fact that analyzed elements were not influenced by other elements. The calibration curves for Ti, Mo, and Ni were drawn from the standard specimens. These diagrams show that the X-ray intensity is proportional to the percentage of each element contained in the cermet tools. It appeared that each element in the cermet tools didn't form perfect solid solution but exists for the most part as a single element. The specimens whose contents are not to the public have been analyzed according to these curves. Reliable estimation for the cutting performance have been given by data of the analysis.View full abstractDownload PDF (1380K)
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