异步轧制与退火铜箔的厚度尺寸效应研究

Research on thickness size effect of asymmetric rolled and annealed copper foils

研究了异步轧制和退火铜箔在室温拉伸过程中的厚度尺寸效应。为研究晶粒尺寸、厚度、厚度晶粒尺寸比和位错密度对力学性能的影响,对轧制后不同厚度的板材一部分进行600℃退火处理作为对比。通过室温单向拉伸实验和电镜观察分别对箔材进行力学性能和微观组织分析。结果表明,材料的极限抗拉强度与晶粒尺寸、厚度、厚度/晶粒尺寸比和位错密度有关。对于轧制态的试样,晶粒尺寸、厚度和位错密度共同作用,使得随着材料厚度的减小,其极限抗拉强度先表现出"越薄越强",然后显现出"越薄越弱"的尺寸效应;而对于退火态试样,仅受厚度方向上晶粒个数的影响,随着材料厚度的降低,其极限抗拉强度表现出"越薄越弱"的尺寸效应现象。在伸长率方面,轧制态和退火态试样都随着材料厚度的减小而逐渐降低。

The thickness size effect of asymmetric rolled and annealed copper foils at room temperature was studied.To study the influence of grain size,thickness,thickness/grain size ratio,dislocation density on mechanical properties,parts of the rolled sheets with different thicknesses were annealed at 600℃as comparison.Through uniaxial tensile experiment at room temperature and electron microscope observation,the mechanical properties and microstructure of foils were analyzed respectively.The results show that the ultimate tensile strength of the material is related to the grain size,thickness,thickness/grain size ratio and dislocation density.For the rolled samples,the grain size,thickness and dislocation density work together,so that as the thickness of material decreases,its ultimate tensile strength shows"the smaller,the stronger firstly",and then shows"the smaller,the weaker".For the annealed samples,it is only affected by the number of grains in the thickness direction.As the thickness of material decreases,its ultimate tensile strength shows the size effect of"the smaller,the weaker".In terms of elongation,it gradually decrease as the thickness of material decreases for both the rolled state and the annealed state samples.