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Volume 35, Issue 12
Displaying 1-8 of 8 articles from this issue
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Sukenari TSUNAKAWA1985 Volume 35 Issue 12 Pages 661-662
Published: December 30, 1985
Released on J-STAGE: July 23, 2008
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Takeo OKI, Takao CHOH, Atsushi HIBINO1985 Volume 35 Issue 12 Pages 663-669
Published: December 30, 1985
Released on J-STAGE: July 23, 2008
JOURNAL FREE ACCESSThe wettability of molten aluminum alloys containing 5% of V, Nb and Ta in Va group and Cr, Mo and W in VIa group to SiC was measured by the dipping method. Wetting of SiC in all the alloys occurs after a certain period. The period is shortened by alloying all elements of Va and VIa groups. These elements without Cr accelerate the wetting rate. EPMA analysis shows formation of (V2C+V) and TaC at the boundary in the alloys containing V and Ta respectively. The reaction rate is expressed by the equation proportional to the number of nuclei for wetting per unit interfacial area and unwetted ratio of the interface (1-α). Activation energy for wetting approximately 330kJ/mol is obtained through temperature dependence of wetting of Al-V alloy.View full abstractDownload PDF (2489K) -
Takeo OKI, Takao CHOH, Atsushi HIBINO1985 Volume 35 Issue 12 Pages 670-677
Published: December 30, 1985
Released on J-STAGE: July 23, 2008
JOURNAL FREE ACCESSThe wettability of molten aluminum alloys containing 5% of Ti, Zr and Hf in IVa group to SiC was measured by the dipping method at 1273 to 1373K. These elements have an effect to improve the wettability of aluminum to SiC. EPMA analysis shows that these elements are concentrated and form carbides at the SiC-aluminum alloy interface. The wetting process were analysed by an equation derived in the previous work. Activation energies for wetting were obtained as 335 and 327kj/mol for Al-Ti and Al-Zr alloys respectively, which are identical to those for pure aluminum and Al-V alloy. Plotting the values of k0 and τ obtained by theoretical analysis against atomic number of alloying elements, a periodic nature is found.View full abstractDownload PDF (2240K) -
Hiroshi KIMURA1985 Volume 35 Issue 12 Pages 678-688
Published: December 30, 1985
Released on J-STAGE: July 23, 2008
JOURNAL FREE ACCESSMethematical models for estimating rolling force P, rolling torque G and forward slip f were developed. These models consist of equations for calculating rolling force function QP, rolling torque function QG, forward slip f, mean flow stress Kfm, temperature of rolled material T and friction coefficient, μ. QP, QG and f equations are derived by the multiple regression analysis of calculated values of Orowan's exact theory, Kfm equation is based on the empirical expression of the experimental data of cam plastometer and besides corrected by the correction parameter. T equation is derived theoretically considering temperature change during air cooling, spray cooling and roll gap. Heat transfer coefficients decided in the former study are used. The values of μ and correction parameter of Kfm are decided simultaneously by substituting measured values of f and P into the f and P models and solving them. Almost satisfactory accuracy is achieved in estimating P, G and f. Improving the accuracy is expected by the use of (coil to coil) plus (lot to lot) adaptive control method.View full abstractDownload PDF (1764K) -
Eiji KATO, Yoshisada UEDA, Toshiro KOBAYASHI1985 Volume 35 Issue 12 Pages 689-695
Published: December 30, 1985
Released on J-STAGE: July 23, 2008
JOURNAL FREE ACCESSTinsile, impact, fracture mechanics and dynamic tear tests were carried out on 7075, 7175 and 7475 alloy extrusions. Fracture toughness of Al-Zn-Mg-Cu alloys is considerably influenced by aging condition. Under-aging results in high fracture toughness and resistances to crack propagation and unstable fracture. The fracture toughness decreases with increasing yield strength. The fact is related to localized plastic deformation due to finely distributed precipitate particles and to the resulting strengthened matrix. Over-aged meterials have lower fracture toughness than the other aged materials. Precipitate particles coagulate at the grain boundary and transgranular fracture at under- and peak-aging conditions transits to intergranular fracture at over-aged condition as the aging proceeds.View full abstractDownload PDF (2179K) -
Mototsugu KATSUTA, Shiro KOHARA, Kenichiro AOKI1985 Volume 35 Issue 12 Pages 696-699
Published: December 30, 1985
Released on J-STAGE: July 23, 2008
JOURNAL FREE ACCESSThe forming limit curves of 3003-O, 3003-H24, 3004-O and 3004-H24 alloy sheets were determined. Effects of strain path on the curves were investigated. Two types of strain paths; equibiaxial tensile straining followed by uniaxial tensile straining (strain path I) and uniaxial tensile straining followed by biaxial tensile straining (strain apth II), were adopted. The strain path I increases the limit strains in the range near the plane strain deformation when the strain in the primary stage is small. The strain path II increases the limit strains in the range of biaxial stretching. The forming limit curves for 3004 alloy sheets are at lower strain side than that for 3003 alloy sheets and the effect of the strain path on the forming limit curve for 3004 sheets is less than that for 3003 sheets.View full abstractDownload PDF (467K) -
Shiro KOHARA, Mototsugu KATSUTA, Kenichiro AOKI1985 Volume 35 Issue 12 Pages 700-704
Published: December 30, 1985
Released on J-STAGE: July 23, 2008
JOURNAL FREE ACCESSForming limit curves of 5052-O and 5052-H34 alloy sheets were determined to assess the formability of the sheets. Effects of strain path on the curves were investigated with two types of two stage strain paths; equibiaxial tensile straining followed by uniaxial tensile straining (strain path I) and uniaxial tensile straining followed by biaxial tensile straining (strain path II). The strain path I has an effect to increase the limit strains in the range near the plane strain deformation. The strain path II has an effect to increase the limit strains in the range of biaxial stretching. The effect of strain path on the forming limit curve depends on combination of the directions of major strain in two stage straining.View full abstractDownload PDF (611K) -
Toshihiko SATO1985 Volume 35 Issue 12 Pages 705-709
Published: December 30, 1985
Released on J-STAGE: July 23, 2008
JOURNAL FREE ACCESSDownload PDF (536K)
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