压合衬套二次冷挤压强化数值仿真与实验研究  

Numerical Simulation and Experimental Study on Secondary Cold Extrusion Strengthening of Pressed Bush

作　　者：刘儒军 黄翔[1] 黄海鸿[3] 陶梅生 殷超超 班许可岭 LIU Rujun;HUANG Xiang;HUANG Haihong;TAO Meisheng;YIN Chaochao;BAN Xukeling(School of Mechanical and Electrical Engineering,Nanjing University of Aeronautics and Astronautics,Nanjing 210016,China;State-owned Wuhu Machinery Factory,Wuhu 241007,Anhui,China;School of Mechanical Engineering,Hefei University of Technology,Hefei 230009,China)

机构地区：[1]南京航空航天大学机电学院,南京210016 [2]国营芜湖机械厂,安徽芜湖241007 [3]合肥工业大学机械工程学院,合肥230009

出　　处：《机械科学与技术》2024年第7期1142-1150,共9页Mechanical Science and Technology for Aerospace Engineering

基　　金：国家自然科学基金项目(51975280)。

摘　　要：采用压合衬套二次冷挤压工艺对7050铝合金耳片孔进行挤压强化;通过X射线衍射仪、三坐标测量机和粗糙度仪,研究二次冷挤压对耳片孔内表面的残余应力、塑性变形以及粗糙度的影响,并通过有限元仿真进行验证。实验结果表明:相较于一次冷挤压,压合衬套二次冷挤压可有效改善试样两端残余应力的不均匀性。随着二次冷挤压相对挤压量增大,残余压应力峰值和应力层深度都进一步增大,塑性变形程度也更大,同时降低了孔壁表面粗糙度。在相对挤压量为2.5%时,最大残余压应力可达-400.3 MPa,并形成了约14 mm的残余压应力层;试样端面A与端面B内径分别增大了0.56 mm和0.54 mm;孔壁表面粗糙度降低幅度达到71.0%。相较于一次冷挤压,二次冷挤压强化后孔壁沿径向形成了更深的残余压应力层和塑性变形层,显著提高了耳片孔的整体服役性能。The ear hole of 7050 aluminum alloy was strengthened by using the second cold extrusion of pressed bush;The effects of the second cold extrusion on the residual stress,plastic deformation,and roughness of the inner surface of the ear hole were studied via X-ray diffractometer,coordinate measuring machine,and roughness meter,and which were verified through finite element simulation.The experimental results show that comparing with that in first cold extrusion,the second cold extrusion of the pressed sleeve can effectively improve the non-uniformity of residual stress at both ends of the sample.As the relative extrusion amount of the second cold extrusion increases,the peak residual compressive stress and the depth of the stress layer increase,and the degree of the plastic deformation increases too,meanwhile the surface roughness of the hole wall decreases.When the relative extrusion amount is 2.5%,the maximum residual compressive stress can reach-400.3 MPa,and there is a residual compressive stress layer of about 14 mm.The inner diameters of the sample end face A and end face B increased by 0.56 mm and 0.54 mm,respectively;the surface roughness of the hole wall decreased by 71.0%.Comparing with the first cold extrusion,the second cold extrusion strengthening forms a deeper residual compressive stress layer and plastic deformation layer along the radial direction of the hole wall,significantly improving the overall service performance of the ear hole.

关 键 词：二次冷挤压 压合衬套 相对挤压量 残余应力 塑性变形 

分 类 号：TG376.3[金属学及工艺—金属压力加工]