The surface tension and specific heat of stable and metastable liquid Ni70.2Si29.8 eutectic alloy were measured by electromagnetic levitation oscillating drop method and drop calorimetry. The surface tension depends o...The surface tension and specific heat of stable and metastable liquid Ni70.2Si29.8 eutectic alloy were measured by electromagnetic levitation oscillating drop method and drop calorimetry. The surface tension depends on tempera- ture linearly within the experimental undercooling regime of 0―182 K (0.12 TE). Its value is 1.693 N·m?1 at the eutectic temperature of 1488 K, and the temperature coefficient is ?4.23×10?4 N·m?1·K?1. For the specific heat measurement, the maximum undercooling is up to 253 K (0.17 TE). The specific heat is determined as a polynomial function of tem- perature in the experimental temperature regime. On the basis of the measured data of surface tension and specific heat, the temperature-dependent density, excess volume and sound speed of liquid Ni70.2Si29.8 alloy are predicted theoreti- cally.展开更多
Fe-58at%Al alloy is undercooled up to 222 K (0.15TL) with the drop tube technique. It is found that there exists a critical undercooling about 185 K, beyond which a 揹endrite-equiaxed?growth morphology transition occu...Fe-58at%Al alloy is undercooled up to 222 K (0.15TL) with the drop tube technique. It is found that there exists a critical undercooling about 185 K, beyond which a 揹endrite-equiaxed?growth morphology transition occurs in FeAl intermetallic compound. This transition is character-ized by sharp decrease of its grain size. Once the undercool-ing exceeds 215 K, the peritectic transformation is sup-pressed completely and a fibrous structure is formed, which results from the cooperative growth of FeAl and FeAl2 com-pounds.展开更多
基金This work was supported by the National Natural Science Foundation of China(Grants No.50121101,50271058&50395 105)Doctorate Foundation of Northwestern Polytechnical University{Grant No.CX200420)the NPU Y oung Teachers Scientific and Technological Innovation Foundation.
文摘The surface tension and specific heat of stable and metastable liquid Ni70.2Si29.8 eutectic alloy were measured by electromagnetic levitation oscillating drop method and drop calorimetry. The surface tension depends on tempera- ture linearly within the experimental undercooling regime of 0―182 K (0.12 TE). Its value is 1.693 N·m?1 at the eutectic temperature of 1488 K, and the temperature coefficient is ?4.23×10?4 N·m?1·K?1. For the specific heat measurement, the maximum undercooling is up to 253 K (0.17 TE). The specific heat is determined as a polynomial function of tem- perature in the experimental temperature regime. On the basis of the measured data of surface tension and specific heat, the temperature-dependent density, excess volume and sound speed of liquid Ni70.2Si29.8 alloy are predicted theoreti- cally.
文摘Fe-58at%Al alloy is undercooled up to 222 K (0.15TL) with the drop tube technique. It is found that there exists a critical undercooling about 185 K, beyond which a 揹endrite-equiaxed?growth morphology transition occurs in FeAl intermetallic compound. This transition is character-ized by sharp decrease of its grain size. Once the undercool-ing exceeds 215 K, the peritectic transformation is sup-pressed completely and a fibrous structure is formed, which results from the cooperative growth of FeAl and FeAl2 com-pounds.
