| Budget Amount *help |
¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1986: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1985: ¥1,200,000 (Direct Cost: ¥1,200,000)
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| Research Abstract |
Effects of the rates of isodynamic compaction of Ti and Ti-6Al-4V powders on the physical and mechanical properties of these green and sintered components was investigated. The order of mean compaction-rate ( <-!・!(epsilon)_V> ) defined as <(1/t_a)1n(V_o/V_a)> <(=(1/t_a)1n(rho_a)/(rho_o))> is <10^(-3)s^(-1)> for quasi-static compaction and it is <10^2s^(-1)> for dynamic compaction, where V, <rho> and t denote volume, density of powder and time, respectively and suffix o and a denote initial and final state, respectively.
1. Isodynamic compaction of Ti powder
(1)The strength, sealing and life of pressure vessel at the isodynamic condition are better than at the isostatic. (2)Compaction energy - relative density curves show less energy is required to achieve the same density if compaction is carried out at high speed. However, peak pressure - relative density curves show that as the rate of compaction is increased the pressure required to achieve a given density must also be increased. (3)
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The deairing from rubber bags containing pre-compacts is essential to obtaining sound green compacts.
2. Electrical discharge pre-compaction and isodynamic compaction of Ti-6Al-4V powder
(1) The magnetic field shaper under the electrical discharge compaction conditions is useful for densifying the powders. (2)The effects of rate of isodynamic compaction on the density and bending strength of green compacts is not clearly recognized.
3. Sintering of Ti and Ti-6Al-4V compacts
Low and high density level compacts manufactured by low and high rates of isodynamic compaction were sintered at five temperature (1000, 1100, 1200, 1300, 1400゜ C) and soaked for three periods of time (15, 60 and 150 min). It was evident from the results that sintering time had comparatively less influence on the properties of sintered parts than that of sintering temperature. (1) For Titanium the sintering temperature 1200゜C is optimum, since the density, tensile strength, elongation and area-reduction of sintered parts are found to be maximum at that temperature. (2) For Ti-6Al-4V the most suitable sintering temperature may be 1300゜C, since the elongation and area-reduction of sintered parts are fornd to be maximum at that temperature. Less
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