Dynamic Mechanical Behavior and Adiabatic Shear Bands of Ultrafine Grained Pure Zirconium

Abstract

Dynamic compression tests were carried out to investigate dynamic mechanical behavior and adiabatic shear bands in ultrafine grained (UFG) pure zirconium prepared by equal channel angular pressing (ECAP) and rotary swaying. The cylindrical specimens were deformed dynamically on the split Hopkinson pressure bar (SHPB) at different strain rates of 800 to 4 000 s-1 at room temperature. The temperature distribution of the shear bands was estimated on the basis of temperature rise of uniform plastic deformation stage and thermal diffusion effect. The results show that the true stress-true strain curves of UFG pure zirconium are concave upward trend of strain in range of 0.02-0.16 due to the effects of strain hardening, strain rate hardening and thermal softening. The formation of the adiabatic shear bands is the main reason of UFG pure zirconium failure. A large number of micro-voids are observed in the adiabatic shear bands, and the macroscopic cracks develop from the micro-voids coalescence. The fracture surface of UFG pure zirconium exhibits quasi cleavage fracture with the characteristic features of shear dimples and river pattern. The highest temperature within the shear bands of UFG pure zirconium is about 592 K.

Keywords

ultrafine grained pure zirconium / dynamic compression / adiabatic shear bands / thermal diffusion

References

[1] Liu C T, Heatherly L, Horton J A, et al. Test Environments and Mechanical Properties of Zr-Base Bulk Amorphous Alloys[J]. Metall. Mater. Trans., 1998, A29(7): 1811-1820.

[2] Park J Y, Choi B K, Yong H J, et al. Corrosion Behavior of Zr Alloys with a High Nb Content[J]. J. Nucl. Mater., 2005, 340(2-3): 237-246.

[3] Valiev R Z. The New Trends in Fabrication of Bulk Nanostructured Materials by SPD Processing[J]. J. Mater. Sci., 2007, 2007(42): 1483-1490

[4] Jiang L, Perez-Prado M T, Gruber P A, et al. Texture, Microstructure and Mechanical Properties of Equiaxed Ultrafine-Grained Zr Fabricated by Accumulative Roll Bonding[J]. Acta Mater., 2008, 200856: 1228-1242.

[5] Sharkeev Y P, Eroshenko A Y, Kulyashova K S, et al. Microstructure, Mechanical and Biological Properties of Zirconium Alloyed with Niobium after Severe Plastic Deformation[J]. Mat.-wiss. u. Werkstofftech., 2013, 44(2-3): 198-204.

[6] Sklenickaa V, Dvoraka J, Kal P, et al. Creep Behavior of a Zirconium Alloy Processed by Equal-Channel Angular Pressing[J]. Acta Phys. Pol., 2012, A122(3): 485-489.

[7] Rogachev S O, Nikulin S A, Khatkevich V M, et al. Effect of Annealing on Structural and Phase Transformations and Mechanical Properties of Ultrafine-Grained E125 Zirconium Alloy Obtained by High-Pressure Torsion[J]. Mater. Lett., 2017, 206: 26-29.

[8] Nikulin S A, Rozhnov A B, Rogachev S O, et al. Investigation of Structure, Phase Composition, and Mechanical Properties of Zr-2.5% Nb Alloy after ECAP[J]. Mater. Lett., 2016, 169: 223-226.

[9] Wongsa-Ngam J, Wen H M, Langdon T G. Microstructural Evolution in a Cu-Zr Alloy Processed by a Combination of ECAP and HPT[J]. Mater. Sci. Eng., 2013, A579: 126-135.

[10] Nikulin S A, Gorshenkov M V, Rozhnov A B, et al. Resistance of Alloy Zr-2.5% Nb with Ultrafine-Grain Structure to Stress Corrosion Cracking[J]. Met. Sci. Heat Treat., 2012, 54(7-8): 407-413.

[11] Dodd B, Bai Y. Adiabatic Shear Localization: Frontiers and Advances[M], 2012 Amsterdam: Elsevier.

[12] Zhao Q, Wu G, Sha W. Deformation of Titanium Alloy Ti-6Al-4V under Dynamic Compression[J]. Comp. Mater. Sci., 2011, 50(2): 516-526.

[13] Wang B, Sun J, Wang X, et al. Adiabatic Shear Localization in a Near Beta Ti-5Al-5Mo-5 V-1Cr-1Fe Alloy[J]. Mater. Sci. Eng., 2015, A639: 526-533.

[14] Mao P L, Yu C J, Zheng L, et al. Microstructure Evolution of Extruded Mg-Gd-Y Magnesium Alloy under Dynamic Compression[J]. J. Magn. Alloy, 2013, 1(1): 64-75.

[15] Jiang L H, Yang Y, Wang Z, et al. Microstructure Evolution within Adiabatic Shear Band in Peak Aged ZK60 Magnesium Alloy[J]. Mater. Sci. Eng., 2018, A711: 317-324.

[16] Zou D L, Luan B F, Liu Q. Microstructural Evolution of Zirconium Alloy under Dynamic Compression at Strain Rate of 1 000 s-1[J]. Trans. Nonferr. Met. Soc. China, 2012, 22(10): 2402-2408.

[17] Wang X Y, Yu P F, Tan C L, et al. Formation and Evolution of Shear Bands in Zr40Ti60 Alloy Impacted by Hopkinson Bar[J]. Mater. Sci. Tech., 2014, 201430: 1 966-1 972.

[18] Zhu D Z, Zheng Z X, Chen Q. Strain-rate Sensitivity of Aluminum 2024-T6/TiB2 Composites and Aluminum 2024-T6[J]. J. Wuhan Univ. Technol., 2015, 30(2): 256-260.

[19] Tiamiyu A A, Badmos A Y, Odeshi A G, et al. The Influence of Temper Condition on Adiabatic Shear Failure of AA 2024 Aluminum Alloy[J]. Mater. Sci. Eng., 2017, A708: 492-502.

[20] Agrawal A K, Singh A. Limitations on the Hardness Increase in 316L Stainless Steel under Dynamic Plastic Deformation[J]. Mater. Sci. Eng., 2017, A687: 306-312.

[21] Wang B F, Liu Z L, Wang B, et al. Microstructural Evolution in Adiabatic Shear Band in the Ultrafine-Grained Austenitic Stainless Steel Processed by Multi-Axial Compression[J]. Mater. Sci. Eng., 2014, A611: 100-107.

[22] Lee B S, Kim M H, Hwang S K, et al. Grain Refinement of Commercially Pure Zirconium by ECAP and Subsequent Intermediate Heat Treatment[J]. Mater. Sci. Eng., 2007, A449-451: 1087-1089.

[23] Zou D L, Luan B F, Liu Q, et al. Formation and Evolution of Adiabatic Shear Bands in Zirconium Alloy Impacted by Split Hopkinson Pressure Bar[J]. J. Nucl. Mater., 2013, 437(1-3): 380-388.

[24] Xiao D W, Li Y L, Hu S H, et al. Compression Deformation Behavior of Pure Zirconium[J]. Rare Metal Mat. Eng., 2008, 200837: 2 122-2 124.

[25] Wang L Y. Dynamtic Mechanical Properties and Adiabatic Shear Behavior of Zr and Zr Alloys[D], 2015 Qinghuangdao: Yanshan University.

[26] Song S G, III Gray G T. Influence of Temperature and Strain Rate on Slip and Twinning Behavior of Zr[J]. Metall. Mater. Trans., 1995, A26(10): 2665-2675.

[27] Choi H J, Kim Y, Shin J H, et al. Deformation Behavior of Magnesium in the Grain Size Spectrum from Nano-to Micrometer[J]. Mater. Sci. Eng., 2010, A527(6): 1 565-1 570.

[28] Liao S C, Duffy J. Adiabatic Shear Bands in a Ti-6Al-4V Titanium Alloy[J]. J. Mech. Phys. Solids, 1998, 46(11): 2 201-2 231.

[29] Liu X Y, Zhao X C, Yang X R, et al. Deformation Behavior and Microstructural Evolution of Ultrafine-Grained Commercially Pure Ti[J]. Adv. Eng. Mater., 2014, 16(4): 371-375.

[30] Liu P, Hu D, Wu Q, et al. Sensitivity and Uncertainty Analysis of Interfacial Effect in SHPB Tests for Concrete-Like Materials[J]. Constr. Build. Mater., 2018, 163: 414-427.

[31] Fan J, Gong X, Qi M, et al. Dynamic Behavior and Adiabatic Shear Bands in Fine-grained W-Ni-Fe alloy under High Strain Rate Compression[J]. Rare Metal Mat. Eng., 2009, 200938: 2 069-2 074.

[32] Wang B F, Yang Y. Microstructure Evolution in Adiabatic Shear Band in Fine-Grain-Sized Ti-3Al-5Mo-4.5V Alloy[J]. Mater. Sci. Eng., 2008, A473(1): 306-311.

[33] Ghaderi A, Barnett M R. Sensitivity of Deformation Twinning to Grain Size in Titanium and Magnesium[J]. Acta Mater., 2011, 201159: 7824-7839.

[34] Kim I, Kim J, Shin D H, et al. Effects of Grain Size and Pressing Speed on the Deformation Mode of Commercially Pure Ti during Equal Channel Angular Pressing[J].. Metall. Mater. Trans., 2003, A34(7): 1 555-1 558.

[35] Hung C, Sun P L, Yu C Y, et al. Inhomogeneous Tensile Deformation in Ultrafine-Grained Aluminum[J]. Scripta Mater., 2005, 53(6): 647-652.

[36] Wang M L, Shan A D. Effect of Strain Rate on the Tensile Behavior of Ultra-Fine Grained Pure Aluminum[J]. J. Alloys Compd, 2008, 455(1-2): L10-L14.

[37] Liu X Y, Zhao X C, Yang X R, et al. Compression Deformation Behaviours of Ultrafine and Coarse Grained Commercially Pure Titanium[J]. Mater. Sci. Tech., 2013, 29(4): 474-479.

[38] Guduru P R, Rosakis A J, Ravichandran G. Dynamic Shear Bands: an Investigation using High Speed Optical and Infrared Diagnostics[J]. Mech. Mater., 2001, 33(7): 371-402.

[39] Bonnet-Lebouvier A S, Molinari A, Lipinski P. Analysis of the Dynamic Propagation of Adiabatic Shear Bands[J]. Int. J. Solids Struct., 2002, 200239: 4249-4269.

[40] Wang X Y, Jing R, Liu C Y, et al. Formation and Evolution of Shear Bands in Cold Rolled Zr40Ti60 Alloy[J]. Mater. Sci. Tech., 2014, 201430: 1205-1208.

[41] Rogers H C. Adiabatic Plastic Deformation[J]. Annu. Rev. Mater. Sci., 1979, 9: 283-311.

[42] Baragar D L. The High Temperature and High Strain-Rate Behaviour of a Plain Carbon and an HSLA Steel[J]. J. Mech. Work. Tech., 1987, 14(3): 295-307.

[43] Zhen L, Li G A, Zou D L, et al. Characterization of the Deformed Microstructure in 1Cr18NiTi Stainless Steel under Ballistic Impact[J]. Mater. Sci. Eng., 2008, A489(1): 213-219.

[44] Wang X B. New Method for Calculating Local Shear Strain in Adiabatic Shear Band of Titanium Alloy[J]. Rare Metal Mat. Eng., 2009, 200938: 1048-1052.

[45] Marchand A, Duffy J. An Experimental Study of the Formation of Adiabatic Shear Bands in a Structural Steel[J]. J. Mech. Phys. Solids, 1988, 36(3): 251-283.