基于改进J-C本构模型的6061铝合金薄壁件温热成形工艺参数优化  

Optimization of Process Parameters for Hot Forming of 6061 Aluminum Alloy Thin-walled Part Based on Improved J-C Constitutive Model

作　　者：倪世东 王勇超 黄庆奕 蔡杨 谢延敏[2] NI Shidong;WANG Yongchao;HUANG Qingyi;CAI Yang;XIE Yanmin(AVIC Chengdu Aircraft Industry(Group)Co.,Ltd.,Chengdu 610091,China;Southwest Jiaotong University,Chengdu 610031,China)

机构地区：[1]中航工业成都飞机工业(集团)有限责任公司,成都610091 [2]西南交通大学,成都610031

出　　处：《航空制造技术》2025年第6期78-85,共8页Aeronautical Manufacturing Technology

摘　　要：6061铝合金密度小,且具有良好的耐腐蚀性、抗氧化及可焊接性,因而被广泛应用于航空航天等领域。但6061铝合金在常温下的成形能力较差,常采用温热成形工艺来提高其薄壁件产品的质量。本文对6061铝合金双C薄壁件温热成形工艺进行了研究,采用单轴热拉伸试验,研究了6061铝合金在不同温度、不同应变率时的变形能力,综合考虑温度与应变率对成形质量的耦合影响,提出了改进的Johnson-Cook(J-C)本构模型来描述材料的流动应力,并利用遗传算法对改进的J-C本构模型参数进行表征。以双C薄壁件为研究对象,建立其差温成形有限元模型,通过正交试验和极差分析,获得各工艺参数对成形质量影响程度的排序;利用拉丁超立方抽样获取训练样本,随机生成测试样本,以双C薄壁件的最大减薄率作为优化目标,通过ABAQUS仿真获取不同样本的响应值;利用改进的BP神经网络建立工艺参数与最大减薄率之间的映射关系,通过改进的遗传算法获取最佳的工艺参数组合,并通过试验验证了该方法的有效性。6061 Aluminum alloy has low density,good corrosion resistance,oxidation resistance and weldability,therefore,is widely used in aerospace field.However,6061 aluminum alloy has poor formability at room temperature,so hot forming technology is normally used to improve the quality of its thin-walled parts.The hot forming process of a double-C thin-walled part of 6061 aluminum alloy was studied in this paper;uniaxial hot tensile tests were conducted to investigate the deformation behavior of 6061 aluminum alloy under different temperatures and strain rates.By comprehensively considering the coupled effects of temperature and strain rate on forming quality,an improved Johnson-Cook(J-C)constitutive model was proposed to describe flow stress of materials,then parameters of the improved constitutive model were characterized using genetic algorithm.A finite element model of nonisothermal forming for the double-C thin-walled part was established,and orthogonal experiments and range analysis were conducted to rank the influence of various process parameters on stamping quality of the double-C thin-walled part.Latin hypercube sampling was employed to obtain training samples,and test samples were randomly generated.The maximum thinning rate of the double-C thin-walled part was taken as the optimization objective and simulation by ABAQUS was used to obtain response values for different samples,then an improved BP neural network was utilized to establish a mapping relationship between process parameters and the maximum thinning rate.The optimal combination of process parameters was obtained through an improved genetic algorithm,and the effectiveness of this method was verified through experiments.

关 键 词：6061铝合金 热拉伸 本构模型 BP神经网络 差温成形 

分 类 号：TG146.21[一般工业技术—材料科学与工程]