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Volume 27, Issue 5
Displaying 1-10 of 10 articles from this issue
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Mutsuo Ohta1963 Volume 27 Issue 5 Pages 197-201
Published: 1963
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe effects of addition of small amount of Mn on the aging process of Al-Cu alloys were studied. The change of electrical resistance during aging were measured at liquid nitrogen temperature, and thin foils made from as quenched alloys were examined by transmission electron microscopy. Results obtained were as follows: (1) The time law of the resistance change was not altered by addition of Mn, and low temperature aging was caused by the formation of G.P.zones of the same kind as Al-Cu. (2) Aging rate was slightly decreased by addition of Mn. (3) It was observed by transmission electron micrography that the number and diameter of helices and loops of dislocation in specimens containing Mn had a resemblance to those in specimens of Al-Cu alloy of lower copper content. (4) Binding energy between a Mn atom (or a pair of Mn-Cu) and a vacancy might be smaller than the sum of binding energy between a Cu atom and a vacancy in eV and 0.1 eV.View full abstractDownload PDF (573K) -
Masahisa Sammonji1963 Volume 27 Issue 5 Pages 202-205
Published: 1963
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSTo the analysis of resistivity distribution at cross section in a pulled Si crystal, the theory of effective distribution coefficient was applied.
The following are illustrations of present report.
(1) Solute concentration at cross section. (Experimental illustration.)
(2) Analysis of concentration distribution at cross section. (On the effective distribution coefficient.)
(3) Resistivity distribution at cross section of phosphorus doped Si crystals. (Experimental.)
(4) Diffusion layer in the melt-solid interface. (On the calculated value with phosphorus doped Si-crystals.)
(5) Resistivity distribution at cross section of boron doped Si-crystals. (Experimental.)
(6) Resistivity distribution at cross section of a boron and phosphorus doped Si-crystal. (With the combination of 3 and 5.)
(7) Discussion. (On the diffusion coefficients of impurities in molten Si.)
The results are in agreement with another impurity doped Si-crystal in an assumption of diffusion coefficient.View full abstractDownload PDF (278K) -
Imao Tamura, Hirofumi Yoshimura, Masao Ibaraki, Masayoshi Tagaya1963 Volume 27 Issue 5 Pages 206-211
Published: 1963
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe effects of ausforming on the hardness and the structure of Fe-Ni and Fe-Ni-C alloys were examined. The results of micro-hardness tests showed that some amount of carbon in steel might be essential for the strengthening by ausforming. Optical micrographs showed that the martensite plate in ausformed specimen was finer than that in unausformed, and bended and kinked. Transmission electron micrographs and the electron diffraction patterns of the structures in ausformed Fe-Ni-C alloy showed as follows: (1) In thin foil for transmission electron microscopy, the martensite plates were severly distorted and bended. This means there are strong stresses in and around martensite plate in the bulk specimen. (2) The twin faults in the martensite crystal in ausformed specimen were also observed. (3) The appearance of martensitic structure in ausformed specimen was in complexion of coarseness. This shows the cloudy distribution of dislocations in the martensite plate and the carbon atoms migrate on these dislocations. The specimen is hardened by precipitation and/or dispersion hardening in such way. In unausformed specimen, carbide may precipitate mainly on twin faults even in early stage of precipitation because of relatively low dislocation density. (4) In ausformed specimen, severly kinked martensite plates were frequently observed. (5) There were tangled dislocations in the austenite of ausformed specimen. This shows the austenite is strain-hardened. (6) The lattice orientation relationship between austenite and martensite in the ausformed Fe-Ni-C alloy approximately obeys usual law, as same as in unausformed.View full abstractDownload PDF (762K) -
Shigeo Aoki1963 Volume 27 Issue 5 Pages 212-216
Published: 1963
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe high temperature oxidation and the mechanical properties of Zr-base ternary alloys shown below have been investigated.
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The oxidation was carried out in dry air at the temperature range of 500°∼700°C. The mechanical properties were measured at the temperature from R.T. to 600°C. The results obtained were summarized as follows: (1) The rates of the oxidation of alloys containing Al are very high and the exponent n in the oxidation process is nearly 1. The reactions follow a liner rate law. (2) In cases of alloys containing Mo, these rates are low and the exponent n is approximately 3, so that the cubic rate law may be applied. (3) The oxidation resistance of Zircaloy-2 in air is not so good. The exponent n is nearly 1 except in the initial period of the oxidation at 500°C. (4) The mechanical strength of alloys containing Al are stronger than these of alloys containing Mo. The strength of Zircaloy-2 at the elevated temperature is the lowest.View full abstractDownload PDF (337K) -
Noboru Makino, Yasuo Kimura, Masaki Suzuki1963 Volume 27 Issue 5 Pages 216-221
Published: 1963
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSMnAl alloy is most succesfully melted by high frequency induction furnace under argon atmosphere in alumina crucible. The alloy containing 68 to 70 wt% of Mn exhibits the highest saturation magnetization in this system. Ferromagnetic phase (π-phase) can be prepared by quenching and subsequent tempering. The adequate quenching temperature is 1100° to 1150°C. When quenched MnAl alloy is tempered at a temperature not exceeding 500°C, its saturation magnetization increases with time and approaches to a common limiting value. Higher the temperature is, more rapidly it reaches to the limit. For example, at 500°C, limiting value is realized within few tens of minuits. Although the specimen tempered at above 500°C losses its magnetic properties after a very rapid increasing in saturation magnetization, the peak value of it is rather higher than the limiting value in lower temperature tempering. X-ray diffraction and microstructure shows that the ferromagnetic phase thus obtained is entirely the same as what obtained through H. Kôno’s “controlled cooling”.View full abstractDownload PDF (765K) -
Toshio Kurosawa, Tetsuo Yagihashi1963 Volume 27 Issue 5 Pages 221-225
Published: 1963
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSFollowing on the previously described small-scale hydrogen reduction, a producing experiment has been carried out using a larger apparatus, graphite and quartz tubes for depostion part, and a source material of purified SiI4 etc. in order to examine problems to be accompanied in producing step. A surface of deposition tube was initially dotted with crystal nucleus of silicon, then these developed with successive nucleation and growth. Silicon was deposited in lump, needle and other forms. Particullarly, in order to use SiI4 more effectively, unreacted SiI4 was traped by cooling, and it was returned to the boiler and reacted repeatedly. Properties of single crystals obtained by Czochralski and floating zone methods were investigated.View full abstractDownload PDF (555K) -
Takayoshi Yoshimori, Tomoo Miwa, Tsugio Takeuchi1963 Volume 27 Issue 5 Pages 226-230
Published: 1963
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIn this report, an accurate and simple method for the determination of boron in steel was described. The pyrohydrolytic separation method of boron was applied for the boron steel. The sample was heated in the furnace at 1350°∼1400°C, and aqueous vapour pre-heated at 900°C was introduced into the reaction tube at the rate of 2∼3.5 mL/min as the liquid water. The aqueous vapour was condensed at the end of the reaction tube, using water jacket condenser, and collected in the dilute solution of sodium hydroxide.
By the above procedure, boron in the sample was completely caught in the collect in 20∼40 min, and the element was determined by the constant current coulometry. The coulometric microdetermination of boron using mannitol [H. Iinuma, T. Yoshimori, H. Takeuchi: Japan Analyst, 7 (1958), 8], was satisfactory for this purpose.
Accurate results were obtained for several boron steels containing 0.0002∼0.01% of boron within 30∼50 min.View full abstractDownload PDF (382K) -
Koichi Furusawa1963 Volume 27 Issue 5 Pages 230-235
Published: 1963
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIn the previous paper on the cause of banded structure, the following results were reported; if two specimens, their chemical composition being different from each other, were welded together and then slowly cooled after austenitizing, inhomogeneous structure appeared, whereas air cooling never showed such a structure. It was also shown that these phenomena were affected by elements such as P, Ni, Cr or Mn.
In the practical welding, it may be occurred that different kind of steels must be welded. In this paper, the effects of the other elements on these phenomena are reported. The results are summarized as follows:—These phenomena are effected not only by Ni, Cr, Mn or P but also by all kind of elements used in this experiment. Although a group of elements makes pearlite structure appear on the side of the specimen in which the element is added, the other one makes ferrite structure there.
In the discussion of these results, two assumptions are introduced, and it was made clear that these phenomena can well be explained from the view point of physical metallurgy.View full abstractDownload PDF (973K) -
Tomoo Suzuki1963 Volume 27 Issue 5 Pages 236-239
Published: 1963
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIn order to investigate the effect of vacuum-melting on properties of a ball bearing steel (JIS SUJ 2), vacuum-melting under various conditions and air-melting were performed by using commercial steels or electrolytic iron as main material for melting. The experimental results obtained were as follows: (1) The dispersions of yield of C,Si,Mn and Cr in steel were smaller on the vacuum-melting than on the air-melting. (2) Without regard to the main material for melting, vacuum-melted steel contains less gases, less “sands”, less non-metallic inclusions than those in air-melted steel. (3) The effects of holding time in vacuum on the various factors such as the chemical composition, the gaseous contents, the sand amounts and the inclusion amounts were studied and also the mutual relation among the factors was made clear.View full abstractDownload PDF (338K) -
Tomoo Suzuki1963 Volume 27 Issue 5 Pages 240-244
Published: 1963
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSBy using the chamotte-, high-alumina-, alumina-and magnesia-crucibles the bearing steel (JIS SUJ 2) was melted in vacuum, and the change in the degree of vacuum during melting, the change of the chemical composition of the melted steel and the structures of the used crucibles were observed. Then the interrelation between the crucibles and the melted steel was studied, and the results were obtained as follows: (1) When the steel was melted in vacuum in chamotte- or high-alumina-crucibles, the lowering of the degree of vacuum during melting was remarkable, and C in steel was markedly decreased more than the case of melting with other crucibles, while Al and Si in steel were increased. Moreover, it was observed that the SiO2 contained in the crucible was decreased on the inner surface in contact with the molten steel. (2) When the steel was melted in alumina-crucibles, C in steel was decreased, while Al in steel was increased. (3) When steel was melted in magnesia-crucibles, little lowering of the degree of vacuum during melting was observed and C was little decreased. In this case, however, the magnesia-crucibles cannot be used again because of cracks.View full abstractDownload PDF (495K)
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