摘要
为研究初生相重熔与反常共晶形成之间的关系,在一定过冷度范围内制备温度再辉被抑制的Ni-19.6%P(摩尔分数)共晶合金薄片试样,得到完全规则的共晶组织。随后将薄片样品快速加热到介于凝固形核与共晶反应之间的特定温度,观察到反常共晶结构的形成,并且反常共晶组织的体积分数随着加热温度的升高而增大。此外,在快速加热后所获得的反常共晶组织中α-Ni的取向随机,而β-Ni_(3)P相则呈现共同的取向。α-Ni为固溶体,但是β-Ni_(3)P为具有一定化学计量比的金属间化合物,充分说明初生规则共晶的重熔正是反常共晶组织的成因。
To investigate the relationship between anomalous eutectic and the remelting of primary phase,thin samples of Ni-19.6at.%P eutectic alloy were solidified over a range of undercoolings with temperature recalescence depressed.Fully regular eutectic structures were obtained.The thin samples were then rapidly heated to certain temperatures between the nucleation and eutectic temperatures,resulting in anomalous eutectic structure.It was found that the volume fraction of anomalous eutectic increased with increasing target temperature.α-Ni particulates were in principle randomly oriented whileβ-Ni_(3)P phase was well oriented in the anomalous eutectic formed upon heating.Considering thatα-Ni is a solid solution whileβ-Ni_(3)P is a stoichiometric intermetallic compound,it is unambiguous that anomalous eutectic forms due to remelting of the primary regular eutectic.
作者
李伟
韦修勋
李金富
Wei LI;Xiu-xun WEI;Jin-fu LI(State Key Laboratory of Metal Matrix Composites,Shanghai Jiao Tong University,Shanghai 200240,China;Shanghai Key Laboratory of Materials Laser Processing and Modification,Shanghai Jiao Tong University,Shanghai 200240,China;School of Materials Science and Engineering,Shanghai Jiao Tong University,Shanghai 200240,China)
基金
supported by the National Natural Science Foundation of China(Nos.51771116,51620105012,51821001)。
关键词
共晶合金
过冷度
非平衡凝固
反常共晶
重熔
eutectic alloy
undercooling
non-equilibrium solidification
anomalous eutectic
remelting
