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Volume 31, Issue 6
Displaying 1-6 of 6 articles from this issue
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Shiro Kohara, Kiyohiko Tatsuzawa1984 Volume 31 Issue 6 Pages 183-188
Published: August 25, 1984
Released on J-STAGE: May 22, 2009
JOURNAL OPEN ACCESSSintering behavior of Fe-Ni compacts prepared with plated powder was studied by means of dilatometric method and electron probe micro analysis. Sintering of the plated powder compacts was enhanced with increasing nickel content, compared with the case of mixed powder. The enhancement of sintering in the plated powder compacts was more dominant in the alpha range than in the gamma range of iron. The mechanism of the enhanced sintering in the plated powder compacts was discussed.View full abstractDownload PDF (3192K) -
Tohru Kohno, Yoshio Nishino, M.J. Koczak, R. Venkatesh1984 Volume 31 Issue 6 Pages 189-195
Published: August 25, 1984
Released on J-STAGE: December 04, 2009
JOURNAL OPEN ACCESSThe influence of graphite addition on the dimensional change and the strength was studied in some sintered mixed elemental alloys, i.e. Fe-Cu-C alloys (Cu; 3%, C; 0-0.9%) and Fe-Cu-P-C alloys (Cu; 3%, P; 0.28%, C; 0-0.9%) and then the effect of phosphorus addition on the sintered Fe-Cu-C alloys was discussed. The phosphorus addition was done by using a Cu-8.4%P eutectic alloy powder.
The results obtained are as follows;
1) In the sintered Fe-Cu-C alloys, the growth of the compacts decreased with increasing graphite content, in contrast, in Fe-Cu-P-C sintered alloys, the dimensional change of the compacts was almost constant with graphite content.
2) With the addition of graphite in the Fe-Cu mixed powder compacts, penetration of the liquid copper into the boundaries of the iron powder particles was reduced, so that copper segregation in the alloy structure was noted particularly for the sintered high carbon Fe-Cu-C alloys. This appears to be attributed the decreasing of the wettability of the liquid copper to the solid iron with increasing the graphite content. In comparison, the sintered Fe-Cu-P-C alloys exhibited the great copper segregation in the alloy structure especially at lower carbon level alloys and this may be attributable to the early stabilization of a-Fe phase with phosphorus and smaller copper solubility in the phase. But high addition of graphite enhances the stability of γ-Fe and allows a more rapid diffusion of copper into the γ-Fe, so that the copper homogeneity in the alloy structure was obtained.
3) The tensile strength of sintered Fe-Cu-P-C alloys was superior to sintered Fe-Cu-C alloys in the range of 0-0.9% graphite content. Additionally the toughness of the Fe-Cu-P-C alloys was extremely high at graphite addition levels below about 0.4%.View full abstractDownload PDF (2941K) -
Tadao Hayasaka, Kazuo Asaka, Shigeru Ozawa1984 Volume 31 Issue 6 Pages 196-201
Published: August 25, 1984
Released on J-STAGE: December 04, 2009
JOURNAL OPEN ACCESSThe objects of this report are to examine the mechanical properties of Fe-Cu-B based sintered alloys containing some other elements such as carbon or some kinds of carbides, and to examine the cold-formability of Fe-Cu-B base sintered compacts and the mechanical properties of cold-forged compacts.
After carburizing, quenching and tempering, the sintered compacts composed of F-e-5Cu-0.15B-0.65Cr-0.1C show a tensile strength of 900 MPa at the density of 7.2g/cm3.
As these sintered compacts show high elongation, it is possible to make parts by cold-forging using these materials.
After carburizing, quenching and tempering, the tensile strength of cold-forged compacts composed of the above mentioned material is more than 1200 MPa.View full abstractDownload PDF (1371K) -
Noboru Suzuki, Atsushi Endo, Hiroshi Utsugi1984 Volume 31 Issue 6 Pages 202-207
Published: August 25, 1984
Released on J-STAGE: May 22, 2009
JOURNAL OPEN ACCESSSilica gel was surface-treated with 1-pentanol at various conditions through gaseous flow method, and the process of treatment was studied by detection of vapor at the end of reaction tube through quadrupole mass spectrometer. The surface property of treated silica gel was inspected by the number of suface group, surface area, dispersive property and infrared spectrum. Results indicate that the appropriate temperature was found to be 350 to 400°C, and a similar result was obtained from the change in ionic current of mass spectra. The pyrolysis of surface-treated silica gel proceeds as same as that of silica gel treated in autoclave. After removing the surface group by heat treatment, both adsorbed amount of argon and surface area were found to be same as those of original silica gel. Therefore, the silica gel substance was thought to be not affected by this treatment. From these results it was recognized that the gaseous flow method was available for the surface treatment as well as the autoclave method.View full abstractDownload PDF (362K) -
Michiko Yonemura, Yoshihide Kotera1984 Volume 31 Issue 6 Pages 208-214
Published: August 25, 1984
Released on J-STAGE: May 22, 2009
JOURNAL OPEN ACCESSThe formation of solid solution in the ZnS-CdS system, one of the simplest reaction which involves two or more phases, has been studied by X-ray diffraction and by the observation of ZnS or CdS phosphor in some stages of the solid solution formation.
Values of activation energy obtained from the height decrease of diffraction lines ZnS (102) are 35 kcal/mol for ZnS : CdS=1 : 1, and 41 kcal/mot for 7 : 3. The formation process was observed by using the phosphor as one of the starting materials. It was assumed that cadmium sulfide sublimates on the first stage of solid solution formation especially when cadmium sulfide is a form of fine powder. The presence of cadmium sulfide on the outer surface of zinc sulfide was observed by EPMA, these results supporting the above assumption. Thereafter the mutual diffusion proceeded to form solid solution. The result of emission measurement coincided with those by EPMA.View full abstractDownload PDF (2634K) -
Shigeyuki Somiya, Masahiro Yoshimura, Matsuo Suzuki, Shun-ichi Hiraish ...1984 Volume 31 Issue 6 Pages 215-220
Published: August 25, 1984
Released on J-STAGE: December 04, 2009
JOURNAL OPEN ACCESSAluminosilicate powders were obtained by hydrothermal treatment of mixed alkoxide solution containing Al2O3:Si02=3:2 (mol ratio) with distilled water at 300-600°C under 10-100 MPa for 2 hr. Very fine crystalline pseudoboehmite (γ-AlOOH)-like phase was formed at 300-500°C under 10-100 MPa. Above 600°C, instead of the pseudoboehmite-like phase, amorphous product was formed under 10 MPa, Al-Si spinel under 50 MPa, and hydralsite (2Al2O3⋅2SiO2⋅H2O), AS(H)-II (close to Al2SiO5), Al-Si spinel and a small amount of mullite (3Al3O3⋅2SiO2-2Al2O3SiO2) under 100 MPa, respectively.
Transmission electron microscope (TEM) revealed that the pseudoboehmite-like phase obtained at 300°C under 50 MPa was thin plate of about 10 nm thick and 100 nm long, and contained homogeneously both Al and Si in the narrow area as a few hundreds nm2, by energy dispersive spectrometric (EDS) analysis. The organic solvent such as benzene and alcohol might stabilize the fine crystals of pseudoboehmite-like phase and prevent the crystalization of hydralsite or As(H)-II.View full abstractDownload PDF (1525K)
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