烧结纯铜热管弯曲表面橘皮微观机制及影响因素分析  

Micro-Mechanism and Influencing Factors of Orange Peel Defects on Bended Surface of Sintered Pure Copper Heat Pipe

作　　者：王松伟 宋鸿武[1] 陈岩[1] 张士宏[1] 胡宽雨 祝焱 Wang Songwei;Song Hongwu;Chen Yan;Zhang Shihong;Hu Kuanyu;Zhu Yan(Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,China;School of Materials Science and Engineering,University of Science and Technology of China,Hefei 230026,China;Zhuhai Longfeng Precision Copper Tube Co.,Ltd.,Zhuhai 519045,China)

机构地区：[1]中国科学院金属研究所,辽宁沈阳110016 [2]中国科学技术大学材料科学与工程学院,安徽合肥230026 [3]广东龙丰精密铜管有限公司,广东珠海519045

出　　处：《稀有金属》2022年第1期1-8,共8页Chinese Journal of Rare Metals

基　　金：国家自然科学基金项目(51875547)资助。

摘　　要：薄壁纯铜热管由于其优异的导热能力而广泛应用于具有高热流密度的微型电子器件产品中。然而,在弯曲变形时管壁外侧的"橘皮"状表面粗化问题成为了热管产品使用的瓶颈。针对薄壁烧结纯铜热管弯曲表面"橘皮"缺陷,采用扫描电镜(SEM)、白光干涉、电子背散射衍射(EBSD)等方法分析了"橘皮"部位的宏观形貌、三维轮廓、面粗糙度以及管壁内微观组织及晶体取向分布,并讨论了杂质元素磷对表面粗糙程度的影响。结果表明:经过烧结处理后,热管壁晶粒长大至壁厚尺度,并形成强烈的Goss型再结晶织构;热管中残留的退火孪晶则具有明显的Copper取向,呈条带状贯穿在基体晶粒中;这种取向差异导致弯曲时表面晶粒间无法协调变形,条带状的孪晶严重阻碍位错滑移,造成表面凹凸起伏;微量杂质磷对热管表面橘皮缺陷有明显的影响,随着磷含量的增加,表面粗糙度数值逐渐增大,表面起伏和橘皮缺陷更加明显。In recent years,with the rapid development of information technology,electronic products have been developing towards miniatur-ization and integration.The thin-walled pure copper sintered heat pipe is widely used in the high-heat-flux electronic devices due to their perfect heat dissipation capacity.In practical application,the heat pipes need to be bent into various shapes to connect the hot end and the cold end.On the surface of the bent section,it usually produces a roughening problem,so-called“orange peel”morphology.This kind of surface defect will lead to an adverse effect on the thermal conductivity as well as the corrosion resistance of the heat pipe,and affect the appearance of the product.The characteristics of the heat pipe made by pure copper tube are as follows:(1)thin-wall(wall thickness≤0.3 mm)and small outer diameter(outer diameter≤6 mm);(2)coarse grains after the sintering process(920~980°C);(3)a large number of annealing twins were produced in the copper tube due to its low stacking fault energy,however,the evolution of annealing twin and its influence on the surface roughening were still lack of report.Therefore,the operation mechanism of surface roughening problem for the bent copper heat pipes and its quantitively relationship with the microstructure and texture components were systematically and deeply studied in this paper.Also,the main reason behind this problem had been analyzed.It was suggested that the pinning of impurity phosphorus on the annealing twin boundary was the main reason for the“orange peel”defect on the bent surface,and the quantitative relationship between impurity phosphorus content and surface roughness(S;)was compared through experiments.In this work,the heat pipe billet was treated by high temperature sintered,then bent with the radius R=11 mm and with the bending angle of 180°.The outer surface of the bent section of heat pipe was cut off as the samples.The macrostructure,three-dimensional profile,surface roughness of the surface defect and the microstruc

关 键 词：铜热管 烧结 退火孪晶 橘皮缺陷 

分 类 号：TG146.11[一般工业技术—材料科学与工程]