ABSTRACT Co-20- wt% Sb hypoeutectic, Co-41.4 st% Sb eutectic, and Co-45 wt% Sb hypereutectic allo... more ABSTRACT Co-20- wt% Sb hypoeutectic, Co-41.4 st% Sb eutectic, and Co-45 wt% Sb hypereutectic alloys were undercooled by up to 224, 225 and 177 K, respectively. The dendritic and eutectic growth velocities during rapid solidification were measured by an infrared technique. It is found that dendrite growth in the hypoeutectic alloy is still in the regime of solute diffusion-controlled growth even at an undercooling of 224 K. A dendritic-equiaxed'' microstructure transition occurs if this hypoeutectic alloy is undercooled by more than 90 K, resulting in an abrupt grain refinement effect. Two undercooling thresholds were observed for the eutectic alloy: below the lower limit of [Delta]T[sup [asterisk]][sub e1] = 50 K lamellar eutectic is the unique growth morphology; above the upper limit of [Delta]T[sup [asterisk]][sub e2] = 150K only anomalous eutectic can grow. Although anomalous eutectic is the product of rapid solidification, it shows much greater thermodynamic stability than the lamellar eutectic formed under slow solidification conditions. The hypereutectic alloy behaves like a eutectic alloy during the rapid solidification at sufficiently large undercoolings.
... This means, the lander has to be designed extremely flexible, able to cope with the wide rang... more ... This means, the lander has to be designed extremely flexible, able to cope with the wide range of possible comet properties. ... g cm3) 0.2 0.7 1,5 rotation period (h) 3 10 240 surface acceleration(m s1) 3 l O5 7104 3103 Table I: Assumed properties of nucleus minimal typical max. ...
... 5 JUNE 1989 recorded by the two sensor elements is shown in Fig. 1(c). Considering the path l... more ... 5 JUNE 1989 recorded by the two sensor elements is shown in Fig. 1(c). Considering the path length diA'erence s [Fig. 1(b)], the velocity of the thermal front can be derived in-dependently for the two detectors, and turns out to be constant throughout the sample. ...
ABSTRACT Co-20- wt% Sb hypoeutectic, Co-41.4 st% Sb eutectic, and Co-45 wt% Sb hypereutectic allo... more ABSTRACT Co-20- wt% Sb hypoeutectic, Co-41.4 st% Sb eutectic, and Co-45 wt% Sb hypereutectic alloys were undercooled by up to 224, 225 and 177 K, respectively. The dendritic and eutectic growth velocities during rapid solidification were measured by an infrared technique. It is found that dendrite growth in the hypoeutectic alloy is still in the regime of solute diffusion-controlled growth even at an undercooling of 224 K. A dendritic-equiaxed'' microstructure transition occurs if this hypoeutectic alloy is undercooled by more than 90 K, resulting in an abrupt grain refinement effect. Two undercooling thresholds were observed for the eutectic alloy: below the lower limit of [Delta]T[sup [asterisk]][sub e1] = 50 K lamellar eutectic is the unique growth morphology; above the upper limit of [Delta]T[sup [asterisk]][sub e2] = 150K only anomalous eutectic can grow. Although anomalous eutectic is the product of rapid solidification, it shows much greater thermodynamic stability than the lamellar eutectic formed under slow solidification conditions. The hypereutectic alloy behaves like a eutectic alloy during the rapid solidification at sufficiently large undercoolings.
... This means, the lander has to be designed extremely flexible, able to cope with the wide rang... more ... This means, the lander has to be designed extremely flexible, able to cope with the wide range of possible comet properties. ... g cm3) 0.2 0.7 1,5 rotation period (h) 3 10 240 surface acceleration(m s1) 3 l O5 7104 3103 Table I: Assumed properties of nucleus minimal typical max. ...
... 5 JUNE 1989 recorded by the two sensor elements is shown in Fig. 1(c). Considering the path l... more ... 5 JUNE 1989 recorded by the two sensor elements is shown in Fig. 1(c). Considering the path length diA'erence s [Fig. 1(b)], the velocity of the thermal front can be derived in-dependently for the two detectors, and turns out to be constant throughout the sample. ...
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