摘要
Fe—Ni—C在扩散型(珠光体)相变时呈现较高的内耗峰,说明相界面(尤其是高能相界面)的运动对相变内耗起到重要作用.建议建立一个内耗峰值与相界面能量之间的关系式.Fe-Ni-C中贝氏体相变的内耗特征与珠光体的相似,贝氏体相变孕育期内已发现相变内耗峰.结合溶质区的实验结果,证明贝氏体相变系扩散形核.马氏体相变中相界面能量较低,导致其内耗峰值低于扩散型相变的峰值.马氏体相变的软模现象为相变形核机制提供启迪.fcc→hcp反铁磁相变抑制了马氏体相变动力学,但促发了fcc→fct相变.在ZrO2-CeO2-Y2O3陶瓷中,因m→t逆相变而引起的滞弹性可称其为伪滞弹性,其弛豫时间长达数日之久.
There exists high damping peak associated with the diffusional pearlitic transformation in Fe-Ni-C, indicating that the motion of interphase, especially the interface with high boundary energy, plays an important role to internal friction. An expression of the relationship between value of internal friction peak and interphase boundary energy is suggested. In Fe-Ni-C, the characteristic of the internal friction associated with the pearlite transformation is similar to that of the bainite transformation. It has been revealed that the internal friction peak appeared in the incubation period of the isothermal bainite transformation and the experiment also found that the solute-depleted zone formed beyond this period. Combination of the above results just implies that the nucleation mechanism of bainite transformation is diffusional. The lower interphase energy in the martensitic transformation results in a lower value of internal friction peak as compared with that in diffusional transformation. The soft mode phenomenon gives an implication for the nucleation mechanism. Antiferromagnetic transition depresses the kinetics of the martensitic transformation fcc-->hcp, but enhances the fcc-->fct transformation. In ZrO2-CeO2-Y2O3 ceramics, anelasticity phenomenon induced by the reverse transformation m-->t may be called pseudo-anelaticity and the relaxation process will proceed as long as several days.
出处
《金属学报》
SCIE
EI
CAS
CSCD
北大核心
2003年第11期1121-1126,共6页
Acta Metallurgica Sinica
关键词
内耗
模量
软模
相变
伪滞弹性
internal friction
modulus
soft mode
phase transformation
pseudo-anslasticity
