Zn-Cu包晶系中的片层状类共晶组织

LAMELLAR EUTECTIC-LIKE STRUCTURE IN PERITECTIC Zn-Cu SYSTEM

采用Ｂｒｉｄｇｍａｎ定向凝固法研究了不同生长速度下Ｚｎ－３．３７％Ｃｕ（质量分数）包晶合金的凝固过程及其组织形态．当生长速度高于１．０ｍｍ／ｓ时，出现片层状类共晶生长，且片层间距和生长速度的关系很好地符合λｖ１／２＝（２１６±４２）μｍ３／２·ｓ－１／２关系，该数值与多数共晶系相比偏高．这类共晶组织在包晶合金中的发现有助于对包晶合金凝固过程的进一步研究．

Zn-3.37%Cu peritectic alloy has been unidirectionally solidified with a wide range of growth velocities. It is found that when the growth velocity is beyond 1.0 mm/s, a new kind of lamellar eutectic-like structure occurs in the solidified samples. Furthermore, the relation between lamellar spacing and growth velocity corresponds to λv 1/2 =(216±42)μ m 3/2 ·s -1/2 where the constant is larger than other eutectic systems.