铝合金薄板n值和r值测试的影响因素分析  

Analysis of influencing factors of n-value and r-value test of aluminum alloy sheet

作　　者：张银祥 陈玉 Zhang Yinxiang;ChenYu(Southwest Aluminum(Group)Co.,Ltd.,Chongqing 401326,China)

机构地区：[1]西南铝业(集团)有限责任公司,重庆401326

出　　处：《铝加工》2023年第4期18-22,共5页Aluminium Fabrication

摘　　要：拉伸应变硬化指数(n值)、塑性应变比(r值)已成为评价材料成形性能的重要指标,因此,n值、r值测试数据的准确性就显得特别重要。本文针对测试中影响n值、r值结果的几个主要因素进行了分析讨论。结果表明,试样尺寸在(12.50±0.20)mm范围内,对n值测试结果几乎无影响;同一个试样用方法A与方法B计算的n值、r值有一定差异;试样装夹偏移角度不超过±3.6°时,对n值几乎无影响;对于全自动引伸计,试样装夹偏移角度对r值影响明显,极限情况下,偏移角度的绝对值达到0.7°时即可能导致r值明显增大。Tensile strain hardening index(n value)and plastic strain ratio(r value)have become important indexes to evaluate the formability of materials,so the accuracy of the test data of n value and r value is particularly important.In this paper,several main fac⁃tors affecting the results of n-value and r-value are analyzed and discussed.The results show that the sample size in the range of(12.50±0.20)mm has almost no effect on the n-value test results.The n value and r value of the same sample calculated by method A and method B are different to some extent.When the sample clamping deviation Angle does not exceed±3.6°,it has almost no effect on n value.For the automatic extender,the sample mounting offset Angle has a significant impact on the r-value.In the limit case,when the absolute value of the offset Angle reaches 0.7°,the r-value may increase significantly.Attention should be paid to alignment during installation to ensure the coaxiality.

关 键 词：铝合金 拉伸应变硬化指数(n值) 塑性应变比(r值) 试验验证 

分 类 号：TG146.21[一般工业技术—材料科学与工程] TG115.52[金属学及工艺—金属材料]