• Textile Coloration and Finishing
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• v.33 no.4
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• pp.327-337
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• 2021

The uniformly dispersed Aramid and Poly (phenylene benzobisoxazole) (PBO) in a variety of rubber was investigated. The mechanical properties of rubber were characterized by hardness, tensile strength, elongation at break, heat resistance, oil resistance, cold resistance, ozone resistance measurements. The 3mm Aramid chopped fiber better tensile strength than the other Chopped fiber. The Aramid of 3mm chopped fiber showed excellent reinforcing in rubber composite because of homogeneous dispersion. Consequently, the best 3mm Aramid chopped fiber and rubber improved the tensile strength and elongation at break of the composite. Also, 3mm Aramid chopped fiber improved the oil-resistant, ozone resistant and cold resistant.

• Journal of Sericultural and Entomological Science
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• v.14 no.1
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• pp.43-47
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• 1972

The tensile properties of cocoon filament obtained from the dried cocoon were studied by deniroscope and tensilon with special attachments. The strength and dried elongation at break feint with dry and swollen samples were observed. The apparent young's modulus was also calculated with the dry samples. The results obtained are as follows. 1) The breaking strength of dry and swollen samples decreased in parallel with denier decreasing ratio in the whole length of a cocoon filament. 2) Tensile strength of inner-layer filament, when treated at the temperature of 95$^{\circ}C$ for 15 min., was 37 per cent of outer-layer filament. 3) By swelling treatment, the breaking strength of the filament was decreased but the elongation was increased. 4) Apparent young's modulus and tensile strength per denier of inner-layer filament were higher than those of the rest cocoon layer.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1999.03b
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• pp.163-170
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• 1999

Although the bulge forming technique is currently employed in commercial superplastic forming processes, the uniaxial tensile test is still the most commonly used method for the evaluation of the superplasticity of materials due to its simplicity in testing. However, the results obtained from the uniaxial tensile test can not be applied in analyzing the characteristics of the real parts formed in multi-axial stress state. In this paper, using the tensile test specimen obtained from the square cup manufactured by superplastic forming, tensile strength and elongation have been investigated according to the strain and cavity volume fraction. From the result of experiment, tensile strength and elongation are decreased according to the strain and cavity in Al-6%Cu-0.4%Zr alloy. On condition of uniaxial stress, cavity volume fraction is increased on linear according to the increasement of thickness strain. However, on condition of biaxial stress there are critical point( E t=1.5-1.6) that the slope, the ratio of cavity volume fraction and strain, have been changed. Therefore, cavity volume fraction is different with respect to stress condition, although the same strain.

• Transactions of Materials Processing
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• v.8 no.3
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• pp.283-283
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• 1999

In the present study, the effect of microporosity on the tensile properties of as-cast AZ91D magnesium alloy was investigated through experimental observation and numerical prediction. The test specimens were fabricated by die-casting and gravity-casting. For gravity-casting, the inoculation and use of various metallic moulds were applied to obtain a wide range of microporosity. The deficiency of the interdendritic feeding of the liquid phase acted as d dominant mechanism on the formation of the micropores in the Mg-Al-alloys, rather than the evolution of hydrogen gas. Although tensile strength and elongation has a nonlinear and very intensive dependence upon microporosity, the yield strength appeared to have a linear relationship with microporosity. However, it was possible to quantitatively estimate the linear contribution of microporosity on the individual tensile property far a range of microporosity, which was below about B %. The numerical prediction suggests that the effect of microporosity on fractured strength and elongation decreased as the strain hardening exponent increased. Furthermore. the shape and distribution of micropores may play a more dominant role than local plastic deformation on the tensile behavior of AZ9lD alloy.

• Journal of Ocean Engineering and Technology
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• v.27 no.4
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• pp.9-13
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• 2013

The tensile properties of high manganese austenitic stainless steel with the two phase structures of deformation-induced martensite and reversed austenite were studied. Reversed austenite with an ultra-fine grain size of less than $0.3{\mu}m$ was obtained by reversion treatment. The two phases structures of deformation-induced martensite and reversed austenite were obtained by an annealing treatment in the range of $500^{\circ}C-700^{\circ}C$ for various times in 70% cold- rolled high-manganese austenitic stainless steel. The volume fraction of the reversed austenite increased rapidly with increases in the annealing temperature and time. In the stainless steel with the two phases of austenite and martensite, the strength decreased rapidly, while the elongation increased slowly and then rapidly increased with an increase in the volume fraction of the reversed austenite. Therefore, the strength and elongation were strongly controlled by the volume fraction of reversed austenite. A good combination of high strength and elongation could be obtained by the mixed structure of reversed austenite and deformation-induced martensite.

• Fashion & Textile Research Journal
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• v.10 no.2
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• pp.236-241
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• 2008

Hair manicure is usually and widely operated in the area of hair-dyeing by the reason that acidic hair color is less damaged and more stable than other chemical color treatment. However, there is no an in-depth study to prove them. This study purposes to provide basic resources for effectively using products of hair manicure by experiments on Physical Properties of Hair. Hair of one healthy woman in mid-20's, Level 4, was sampled for experiments. For the tests, hair samples were classified by the frequency of hair manicure treatment The control group(a), once treatment(b), twice(c), three times(d), four times(e) and five times(f). The results were measured with Scanning Electron Microscopy(SEM) and Tensile Strength and Elongation test. The lower Values of Tensile Strength according to repeated hair manicure treatment. Elongation is not affected by the frequency of hair manicure treatment. There was no remarkable change of hair surface in once(b) and twice(c) treatment. The change of hair surface which was able to judge by cuticle layers looseness, tunics and the transformation of cuticle cell were observed in the hair samples operating more than three times(d) of hair manicure treatment.

• Journal of the Korean Society for Heat Treatment
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• v.10 no.4
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• pp.278-287
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• 1997

The TRIP behavior in tensile deformation of retained austenite formed by reverse transformation treatment in 0.15%C-6%Mn-(Ti, Nb) steels has been investigated. The shape of retained austenite was almost a fine lath type with $0.1{\sim}0.3{\mu}m$ width and the two distinctly different transformation sequences of retained austenite, i) retained austenite${\rightarrow}$martensite and ii) retained austenite${\rightarrow}$deformation twin${\rightarrow}$martensite were revealed. The strength-elongation combination was increased with increasing the holdig time at low temperatures ($625^{\circ}C$) but decreased abruptly with increasing holding time at high temperatures ($675^{\circ}C$), owing to the lowering of ductility. The strength-elongation combination and TRIP effect was lower in tensile deformation in the range of $100{\sim}250^{\circ}C$ than room temperature. The tensile strengh and elongation of a reverse transformed steels with addition of Ti or Nb was 93kg/, 40% respectively, which is higher over 10% of strength without ductility loss than in 0.15%C-6%Mn steels.

• Carbon letters
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• v.8 no.2
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• pp.115-119
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• 2007

Properties of carbon blacks and carbon black/SBR rubber composites filled by surface modified carbon blacks were examined. Although the specific surface area of carbon blacks increased after the surface modifications with heat, acid, and base, there were no obvious changes in resistivity. The composites filled by heat treated carbon blacks showed a higher tensile strength and elongation than those filled by raw blacks. The acid and base treated carbon blacks filled composites also showed higher tensile strength but similar elongation values with those filled by raw blacks. With increasing loading ratio, both tensile strength and elongation increased, and appeared a maximum value at 30-40 phr. Modulus at 300% strain remained increasing with further loading of carbon blacks. At the same loading, the heat treated black filled composites showed similar modulus values with composites filled by raw blacks but for base and acid treated black filled composites much higher values were obtained. After the surface modification, the functional groups which played an important role in reinforcement action were changed.

• Journal of Korea Foundry Society
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• v.17 no.5
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• pp.443-449
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• 1997

The purpose of this study is to investigate the effect of P addition and homogenizing heat treatment on the mechanical properties of Cu-Sn-Ni alloy. The addition of P was 0.025wt.%P to 0.085wt.%P and homogenizing heat-treated at 400, 500, $600^{\circ}C$ under $N_2$ gas atmosphere. Mechanical properties was investigated in this study were Rockwell hardness, tensile strength, and elongation. Tensile strength and elongation increased with P and homogenizing time. Temperature was significantly influence on mechanical properties. Hardness decreased with increasing homogenizing time and temperature, but 0.085wt.%P specimen was showed higher hardness and lower tensile strength and elongation than 0.073wt.%P specimen due to the presence of more $Cu_3P$ in matrix.

• Journal of the Korean Society of Safety
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• v.20 no.3 s.71
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• pp.58-63
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• 2005

In this research, silicone rubber with additions of inorganic filler, alumina trihydrate$(Al(OH)_3\;:\;ATH)$, was aged acceleratedly and cyclically by the salt-fog and heating. The optimum amount of ATH addition to silicone rubber have been investigated by measurements of leakage current in the change of electrical properties and tensile strength, %elongation in mechanical properties and FT-IR, TG, SEM in the change of the chemical properties. With regard to un-aged silicone rubber, as the ATH addition amount increases, conductive path formation time was shortened in the electrical properties and tensile strength was increased, %elongation was decreased. In case of identical ATH addition amount, as cyclic aging increases, surface resistivity, tensile strength and %elongation were decreased. Considering the cyclic aging, the most effective amount of ATH addition was about 90phr.