New Process and Mechanism for Preparing Gradient Structural Aluminum Strip by Extrusion-machining

doi:10.3901/JME.2022.05.278

Abstract

Abstract: Extrusion-Machining is a kind of novel severe plastic deformation process. Through the design of specific material plastic flow channel, the ultrafine-grained metal sheets or strips with gradient structure can be prepared by the one-step method under the combined action of machining and extrusion. It has the obvious advantages of simple process, mature equipments and high manufacturing efficiency. Currently, there is very few research on the forming process, mechanism of Extrusion-Machining and the performance of gradient ultrafine-grained microstructure materials prepared by it. Through a combination of theoretical, experimental and numerical analysis, the forming process of gradient structural aluminum strip 1060 under different extrusion thicknesses is investigated. The influence of the machining mechanism and process parameters of Extrusion-Machining on the preparation of samples is analyzed. The results show that with the increase of the extrusion thickness, no significant change in the range of high-strain areas, but the low-strain zone is more widely distributed, and more material is extruded laterally. The gradient structural aluminum strip has significant grain refinement and hardness enhancement, which both show obvious gradient distribution in the thickness layer. The tensile strength of gradient sample decreases with the increase of extrusion thickness, while the elongation increases. The tensile strength of the gradient structural aluminum strip is almost twice higher than that of the original sample, while the elongation only decreases slightly. This study implies that Extrusion-Machining is a feasible and efficient process for preparing gradient structure materials, which can be used for preparing materials with different gradient distributions by adjusting the process parameters.

Key words: extrusion-machining, gradient structural aluminum strip, gradient ultrafine-grained microstructure

CLC Number:

TG376

DENG Wen-jun, CENG Yu-ning, ZHOU Zi-han. New Process and Mechanism for Preparing Gradient Structural Aluminum Strip by Extrusion-machining[J]. Journal of Mechanical Engineering, 2022, 58(5): 278-288.

References

[1] KAWASAKI M,FIGUEIREDO R,LANGDON T.An investigation of hardness homogeneity throughout disks processed by high-pressure torsion[J].Acta Materialia,2011,59(1):308-316.
[2] LUO Junting,YU Wenlu,XI Chenyang,et al.Preparation of ultrafine-grained GH4169 superalloy by high-pressure torsion and analysis of grain refinement mechanism[J].Journal of Alloys and Compounds,2019,777:157-164.
[3] GASHTI S,FATTAH-ALHOSSEINI A,MAZAHERI Y,et al.Effects of grain size and dislocation density on strain hardening behavior of ultrafine grained AA1050processed by accumulative roll bonding[J].Journal of Alloys and Compounds,2016,658:854-861.
[4] SU Lihong,LU Cheng,LI Huijun,et al.Investigation of ultrafine grained AA1050 fabricated by accumulative roll bonding[J].Materials Science and Engineering:A,2014,614:148-155.
[5] REIHANIAN M,EBRAHIMI R,MOSHKSAR M,et al.Microstructure quantification and correlation with flow stress of ultrafine grained commercially pure Al fabricated by equal channel angular pressing (ECAP)[J].Materials Characterization,2008,59(9):1312-1323.
[6] SHAERI M,DJAVANROODI F,SEDIGHI M,et al.Effect of copper tube casing on strain distribution and mechanical properties of Al-7075 alloy processed by equal channel angular pressing[J].The Journal of Strain Analysis for Engineering Design,2013,48(8):512-521.
[7] VALIEV R.Nanostructuring of metals by severe plastic deformation for advanced properties[J].Nature Materials,2004,3(8):511-516.
[8] KOCH C.Optimization of strength and ductility in nanocrystalline and ultrafine grained metals[J].Scripta Materialia,2003,49(7):657-662.
[9] DING Jie,LI Q,LI Jin,et al.Mechanical behavior of structurally gradient nickel alloy[J].Acta Materialia,2018,149:57-67.
[10] LU Ke.Making strong nanomaterials ductile with gradients[J].Science,2014,345(6203):1455-1456.
[11] LI Jianjun,CHEN Shaohua,WU Xiaolei,et al.A physical model revealing strong strain hardening in nano-grained metals induced by grain size gradient structure[J].Materials Science & Engineering A,2015,620:16-21.
[12] JIN Hanxun,ZHOU Jianqiu,CHEN Yunqi.Grain size gradient and length scale effect on mechanical behaviors of surface nanocrystalline metals[J].Materials Science & Engineering A,2018,725:1-7.
[13] VU V,YAN B,TOTH L,et al.The plastic flow machining:A new SPD process for producing metal sheets with gradient structures[J].Materials Characterization,2018,138:208-214.
[14] 卢柯.梯度纳米结构材料[J].金属学报,2015,51(1):1-10.LU Ke.Gradient nanostructured materials[J].Acta Metallurgica Sinica,2015,51(1):1-10.
[15] LIN Yan,PAN Jie,ZHOU Haofei,et al.Mechanical properties and optimal grain size distribution profile of gradient grained nickel[J].Acta Materialia,2018,153:279-289.
[16] 李毅.梯度结构金属材料研究进展[J].中国材料进展,2016,35(9):658-665,700-701.LI Yi.Research progress of metal materials with gradient structure[J].Materials China,2016,35(9):658-665,700-701.
[17] CAI Baozhuang,MA Xiaolong,MOERING J,et al.Enhanced mechanical properties in Cu-Zn alloys with a gradient structure by surface mechanical attrition treatment at cryogenic temperature[J].Materials Science & Engineering A,2015,626:144-149.
[18] WANG Panfeng,HAN Zheng,LU Ke.Enhanced tribological performance of a gradient nanostructured interstitial-free steel[J].Wear,2018,402:100-108.
[19] XIN Chao,SUN Qiaoyan,XIAO Lin,et al.Biaxial fatigue property enhancement of gradient ultra-fine-grained Zircaloy-4 prepared by surface mechanical rolling treatment[J].Journal of Materials Science,2018,53(17):12492-12503.
[20] YIN Zhe,YANG Xincheng,MA Xiaolong,et al.Strength and ductility of gradient structured copper obtained by surface mechanical attrition treatment[J].Materials & Design,2016,105:89-95.
[21] FANG Tiehui,LI W L,TAO Nairong,et al.Revealing extraordinary intrinsic tensile plasticity in gradient nano-grained copper[J].Science,2011,331(6024):1587-1590.
[22] XIN Chao,SUN Qiaoyan,XIAO Lin,et al.Synergetic strengthening of grain refinement and texture in gradient zircaloy-4 by surface mechanical rolling treatment[J].Journal of Materials Engineering and Performance,2019,28(10):6354-6364.
[23] ASGARI M,FERESHTEH-SANIEE F,PEZESHKI S,et al.Non-equal channel angular pressing (NECAP) of AZ80 Magnesium alloy:Effects of process parameters on strain homogeneity,grain refinement and mechanical properties[J].Materials Science & Engineering A,2016,678(10):320-328.
[24] LEE D.An upper-bound solution of channel angular deformation[J].Scripta Materialia,2000,43(2):115-118.
[25] 许德鹏.1060铝多道次等通道角变形(ECAP)数值模拟及实验研究[D].青岛:青岛理工大学,2013.XU Depeng.Numerical simulation and experimental investigation of 1060 Al in equal channel angular pressing[D].Qingdao:Qingdao University of Technology,2013.