快速凝固条件下Ni-Pb偏晶合金的组织演变机理研究  

Continuous Microstructure Evolution of Ni-Pb Monotectic Alloy under Rapid Solidification

作　　者：唐跃跃 赵李新 陈正[2] TANG Yue-yue;ZHAO Li-xin;CHEN Zheng(JiangSu Vilory Advanced Material Science and Technology Co.,Ltd,Jiangsu Xuzhou 221001,China;School of Material and Physics,China University of Mining and Technology,Jiangsu Xuzhou 221116,China)

机构地区：[1]江苏威拉里新材料科技有限公司,江苏徐州221001 [2]中国矿业大学材料与物理学院,江苏徐州221116

出　　处：《精密成形工程》2022年第6期148-153,共6页Journal of Netshape Forming Engineering

摘　　要：目的研究过冷Ni-0.5%Pb(原子数分数)合金过冷组织的演化行为,阐明其组织演化和晶粒细化的基本机制。方法采用熔融玻璃净化和循环过热方法制备出过冷度为0~255 K的试样,并结合枝晶生长的动力学-热力学模型,研究其深过冷快速凝固行为机制。结果在0~255 K过冷度范围内,随着过冷度的增大,Ni-Pb偏晶合金的微观组织发生了2类晶粒细化现象,组织形态由粗大树枝晶向粒状等轴晶转变。结论第1类粒状晶的形成是由于枝晶熟化和再辉重熔导致发达枝晶破碎,第2类粒状晶的形成是由于在应力和应变能的作用下,枝晶碎变和再结晶引起了晶粒细化。This paper aims to study the subcooled microstructure evolution behavior of supercooled Ni-0.5%Pb(atomic fraction)alloys,and to clarify the basic mechanism of microstructure evolution and grain refinement.The samples with subcooling degree of 0-255 K were prepared by the method of molten glass purification and cyclic superheating,and combined with the kinetic-thermodynamic model of dendrite growth,the mechanism of rapid solidification behavior in deep subcooling was studied.In the range of 0-255 K undercooling,with the increase of undercooling,two types of grain refinement occurred in the microstructure of Ni-Pb monotectic alloy,and the microstructure changed from coarse dendrite to granular equiaxed.crystal transformation.The formation of the first type of granular crystals is due to the fragmentation of developed dendrites caused by dendrite maturation and re-melting.The formation of the second type of granular crystals is due to dendrite fragmentation and recrystallization under the action of stress and strain energy.

关 键 词：Ni-Pb合金 过冷组织演化 深过冷 晶粒细化 应力积累 

分 类 号：TG146.1[一般工业技术—材料科学与工程]