摘要
对ZL208合金进行不同温度(550~580℃)×8 h的固溶处理和220℃×16 h时效处理,研究了固溶温度对其组织和性能的影响。结果表明,ZL208合金经固溶时效处理后部分组织由枝晶转变为等轴晶。随着固溶温度的升高,晶界处第二相颗粒尺寸先减小后增大,合金的抗拉强度、硬度和断后伸长率呈现出先增大后减小的趋势。这是由于固溶温度升高使Cu、Ni原子在α-Al基体中的溶解度增大,提高了基体抵抗塑性变形的能力,同时晶界处的第二相还可以限制晶粒的生长,从而提高合金的强度和硬度。但固溶温度为580℃时,出现过烧现象,对合金性能不利。因此,ZL208合金最优的固溶时效工艺为:570℃×8 h+220℃×16 h,经该工艺处理后,其抗拉强度为336.87 MPa,屈服强度为210.45 MPa,硬度为97.48 HV0.1,断后伸长率为8.56%,断裂方式为脆性断裂。
ZL208 alloy was subjected to solid solution treatment at different temperatures(550-580℃)for 8 h and aging at 220℃for 16 h,and the effect of solid solution temperature on its microstructure and properties was studied.The results show that after solid solution and aging treatment,the microstructure of ZL208 alloy partially transforms from dendrites to equiaxed crystals.With the increase of solid solution temperature,the size of the second phase particles at the grain boundary decreases firstly and then increases.The tensile strength,hardness and elongation after fracture of the alloy show a trend of first increasing and then decreasing.This is because the increase in solid solution temperature increases the solubility of Cu and Ni atoms in theα-Al matrix,improving the ability of matrix to resist plastic deformation.At the same time,the second phase at the grain boundary can also restrict grain growth,thereby improving the strength and hardness of the alloy.However,when the solid solution temperature is 580℃,overburning occurs,which is detrimental to the properties of the alloy.Therefore,the optimal solid solution and aging process for the ZL208 alloy is 570℃×8 h+220℃×16 h.After this process,its tensile strength is 336.87 MPa,yield strength is 210.45 MPa,hardness is 97.48 HV0.1,elongation after fracture is 8.56%,and the fracture mode is brittle fracture.
作者
何兴懿
张晓波
He Xingyi;Zhang Xiaobo(State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals,Lanzhou University of Technology,Lanzhou Gansu 730050,China)
出处
《金属热处理》
CAS
CSCD
北大核心
2024年第12期27-33,共7页
Heat Treatment of Metals
基金
甘肃省科技重大专项计划-工业领域(24ZDGJ001)。
关键词
ZL208合金
固溶温度
组织
力学性能
ZL208 alloy
solid solution temperature
microstructure
mechanical properties
