Transactions of Materials and Heat Treatment

Title：Study on inclusion induced microcracking defects on surface of ultra-thin lead frame copper alloy strip

Authors： Cheng Rentao1 Ma Zizai2 Wang Jianghui3 Wang Xiaoguang1

Unit： 1.College of Materials Science and Engineering Taiyuan University of Technology 2.College of Chemistry Taiyuan University of Technology 3.Department of Mechanical Engineering Taiyuan Institute of Technology

KeyWords： lead frame copper alloy surface defect microcrack element segregation inclusion

ClassificationCode：TG146.1

year,vol(issue):pagenumber：2024,49(3):94-100

Abstract：

For the microcracks on the surface of ultra-thin lead frame copper alloy strip, the surface morphology, element distribution, metallographic structure and mechanical properties of copper alloy strip were tested and analyzed by scanning electron microscope (SEM), energy dispersive spectrum (EDS), crystallographic microscopy and nanoindenter, and the cause for the formation of microcrack regions according to their variations was discussed. The results show that the average length of cracks is about 10 μm, and it distributes randomly on both sides of the copper alloy strip, and perpendicular to the rolling direction. The segregation of C and O elements occurs in the melting process of copper alloy, and C, O and Cu inclusions are generated. The matrix is deformed during the rolling process, and the stress concentration occurs at the inclusions, resulting in the formation of microcracks. Finally, according to the cause of microcracks on the surface, some suggestions are put forward to improve the casting and rolling processes and reduce the occurrence of microcracks.

Funds：

国家自然科学基金资助项目（21878201，22008165）；山西省自然科学基金资助项目（202303021211035）

作者简介：成仁韬（1999-），男，硕士研究生，E-mail：1710105610@qq.com；通信作者：王孝广（1982-），男，博士，教授，E-mail：wangxiaoguang@tyut.edu.cn

Reference：

[1]刘劲松, 武安琪, 王松伟，等. 时效处理对冷轧铜镍硅合金板带组织及性能的影响[J]. 锻压技术, 2022, 47(8): 215-223.

Liu J S，Wu A Q，Wang S W，et al. Effect of aging treatment on microstructure and properties of cold rolled Cu-Ni-Si alloy strip[J]. Forging & Stamping Technology，2022, 47(8): 215-223.

[2]王碧文. 引线框架铜合金新材料研制现状及发展[J]. 世界有色金属，2012，(8)：58-59.

Wang B W. Status and development of new materials for lead frame copper alloys[J]. World Nonferrous Metals, 2012，(8): 58-59.

[3]任忠平, 贺东升, 尹国钦. 蚀刻型铜基引线框架材料应用研究[J]. 科技创新与应用，2013，(8)：34.

Reng Z P, He D S, Yin G Q. Study on the application of etched copper-based lead frame materials[J]. Technology Innovation and Application, 2013，(8): 34.

[4]李龙健, 于凤云, 李仁庚，等. 高性能铜合金研究现状及发展趋势[J]. 特种铸造及有色合金，2021, 41(3)：293-298.

Li L J, Yu F Y, Li R G, et al. Research progress and development trend of high-performance Cu alloys[J]. Special Casting & Nonferrous Alloys, 2021, 41(3): 293-298.

[5]姜业欣，娄花芬，解浩峰，等. 先进铜合金材料发展现状与展望[J]. 中国工程科学，2020，22(5)：84-92.

Jiang Y X, Lou H F, Xie H F, et al. Development status and prospects of advanced copper alloy [J]. Strategic Study of CAE, 2020, 22(5): 84-92.

[6]张文芹，郑晨飞. 铜及铜合金带材表面质量控制及技术现状[J]. 有色金属材料与工程，2016，37(4)：125-131.

Zhang W Q, Zheng C F. Surface quality control and technical actuality of copper and copper alloy strip[J]. Nonferrous Metal Materials and Engineering, 2016, 37(4): 125-131.

[7]路彪，田新杰，杨媛媛. 脱脂酸洗对铜合金框架材料表面质量的影响[J].有色金属加工，2017，46(2)：28-32.

Lu B, Tian X J, Yang Y Y. The influence of degrease pickling on surface quality of copper alloy frame material [J]. Nonferrous Metals Processing, 2017, 46(2): 28-32.

[8]Wang J Y, Jiang H T, Duan X G, et al. Orientation and microstructure topology-governed crack propagation behavior in AA7021 aluminum alloys during uniaxial tension[J]. Materials Science and Engineering：A, 2018, 739: 254-263.

[9]陈远星，刘志坚，李燕群. 铬锆铜合金裂纹原因分析[J]. 南方金属，2023，(2)：1-3，44.

Chen Y X, Liu Z J, Li Y Q. Analysis of the cause of crack formation in Cr-Zr-Cu alloy [J]. Southern Metals, 2023，(2): 1-3，44.

[10]黄国杰，谢水生，方奶云，等. KFC铜合金带材表面粗糙缺陷的研究[J]. 特种铸造及有色合金，2007，(S1)：146-147.

Huang G J, Xie S S, Fang N Y, et al. Study on the rough surface of KFC copper strip[J]. Special Casting & Nonferrous Alloys, 2007，(S1): 146-147.

[11]Gao W F. Formation and prevention of sliver defects on the surface of cold-rolled strip[J]. Advanced Materials Research, 2011, 402: 221-226.

[12]王磊. Cu-Fe合金凝固组织性能研究[D]. 沈阳：东北大学，2010.

Wang L. Study on the Solidification Structure and Properties of Cu-Fe Alloy[D]. Shenyang: Northeastern University, 2010.

[13]Malin A S, Hatherly M. Microstructure of cold-rolled copper[J]. Metal Science，1979, 13(8): 463-472.

[14]翟俊，郎炜昀，杨永杰. 不锈钢典型夹杂物在轧制过程的衍变分析[J]. 中国冶金，2023，33(1)：123-130.

Zhai J, Lang W J, Yang Y J. Analysis for evolution of typical inclusions in stainless steel during rolling[J]. China Metallurgy, 2023, 33(1): 123-130.

[15]张明玉，运新兵，伏洪旺. 冷轧TA1钛带材表面缺陷研究[J]. 锻压技术，2022，47(6)：125-131.

Zhang M Y, Yun X B, Fu H W. Study on surface defects for cold rolled TA1 titanium strip[J]. Forging & Stamping Technology, 2022, 47(6): 125-131.

[16]张迪,张朋彦,于帅，等.冷轧带钢表面缺陷的研究与原因分析[J].热加工工艺,2024,53(13):147-151+158[2023-03-13].https://doi.org/10.14158/j.cnki.1001-3814.20213308.

Zhang D，Zhang P Y，Yu S, et al. Research and cause analysis of surface defects of cold rolled strip steel[J]. Hot Working Technology,2024,53(13):147-151+158[2023-03-13].https://doi.org/10.14158/j.cnki.1001-3814.20213308.

[17]焦晓亮，张勇，曹虎成，等. 铍铜带材冲压成型开裂原因分析[J]. 世界有色金属，2019，(14)：116-117.

Jiao X L, Zhang Y, Cao H C, et al. Cause analysis of cracking in stamping forming of beryllium copper strip[J]. World Nonferrous Metals, 2019, (14): 116-117.

Service：

【This site has not yet opened Download Service】【Add Favorite】