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Relationship between vein-like pattern and plasticity in Ti–Cu–Ni–Zr–Hf bulk metallic glasses
Results in Physics 7 (2017) 1513–1515
Contents lists available at ScienceDirect
Results in Physics journal homepage: www.journals.elsevier.com/results-in-physics
Relationship between vein-like pattern and plasticity in Ti–Cu–Ni–Zr–Hf bulk metallic glasses Peiyou Li School of Materials Science and Engineering, Shaanxi University of Technology, Hanzhong 723001, People’s Republic of China
a r t i c l e
i n f o
Article history: Received 24 March 2017 Received in revised form 9 April 2017 Accepted 10 April 2017 Available online 25 April 2017 Keywords: Ti-Cu-Ni-Zr-Hf Phenom scanning electron microscope Vein-like pattern Plasticity
a b s t r a c t The relationship between vein-like patterns and plasticity was investigated in Ti29.44Cu46.72Ni7.88Zr7.6Hf8.4 and Ti31.4Cu43.8Ni8.8Zr7.6Hf8.4 bulk metallic glasses. By observing the fracture morphology of the samples using a phenom scanning electron microscope (PSEM), we demonstrated that a large or small plasticity results in a large or small average height of ‘‘projection” in the vein-like patterns, respectively. The results indicate that, if the height of ‘‘projection” in the vein-like pattern is large or small, the absorptive plastic work is also large or small, in turn indicating that the plasticity of the corresponding metallic glasses is large or small, respectively. The height of ‘‘projection” in the vein-like pattern was determined to reveal the degree of plasticity in Ti-Cu-Ni-Zr-Hf metallic glasses. Ó 2017 The Author. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
Introduction The fracture surfaces of compressive metallic glasses (MGs) exhibit a complicated morphology. Because abundant fracture information is stored on the surface of fracture [1–5], investigation of the surface roughening morphology is an effective method for elucidating the fracture behavior and mechanism of a material [4]. Diverse patterns such as dimple structures [4,6,7], periodic corrugations [5,8], and river- and vein-like patterns [7,9] have been observed on the fracture surface of different MGs using twodimensional (2D) black and white scanning electron microscopy (SEM) images. However, the height and depth of diverse patterns cannot be shown in two-dimensional images. In this work, using a third-generation phenom scanning electron microscope (PSEM), we investigated the relationship between the ‘‘projection” of vein-like patterns and plasticity in Ti–Cu–Ni– Zr–Hf bulk metallic glasses (BMGs) is investigated from both scientific and commercial viewpoints because of their high strength and good plasticity [10]. The relationship between the absorptive plastic work and the plasticity of the corresponding material is also discussed.
Experimental procedure Ingots of Ti29.44Cu46.72Ni7.88Zr7.6Hf8.4 and Ti31.4Cu43.8Ni8.8Zr7.6Hf8.4 alloys with nominal composition were prepared by arc-melting a E-mail address: [email protected]
mixture of pure metal elements (with purities greater than 99.9%) in a titanium-gettered argon atmosphere. The ingots were re-melted at least four times to achieve chemical homogeneity and then suction cast into copper molds to form rod-shaped samples with a diameter of 2 mm. A cylindrical sample with a diameter of 2 mm and a height of approximately 4 mm was prepared from the as-cast rods for uniaxial compression tests. The compression tests were conducted at room temperature in a SANS 1500 compression testing machine. Two- and three-dimensional (3D) images for the fracture surfaces of the samples were acquired using a third-generation PSEM operated at an accelerating voltage of 15 kV.
Results and discussion In the 2D SEM map, the high plasticity is related to the formation of multiple shear bands. However, the relationship between the plasticity and the depth of vein patterns cannot be exhibited via two-dimensional SEM. On the basis of the limitations of 2D SEM imaging, we investigated the relationship between the plasticity and the depth of vein patterns using 3D SEM diagrams. To simplify the analysis, we selected the Ti29.44Cu46.72Ni7.88Zr7.6Hf8.4 sample with the largest plastic strain of 1.8% and the Ti31.4Cu43.8Ni8.8Zr7.6Hf8.4 sample with the smallest plastic strain of 0.3% for PSEM observation in four Ti-Cu-Ni-Zr-Hf BMGs from Ref. [10]. The PSEM graphs of the fracture surface of the Ti29.44Cu46.72Ni7.88Zr7.6Hf8.4 BMG are shown in Fig. 1. As shown in
http://dx.doi.org/10.1016/j.rinp.2017.04.012 2211-3797/Ó 2017 The Author. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
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P. Li / Results in Physics 7 (2017) 1513–1515
Fig. 1. PSEM graphs of the vein-like pattern in the fracture surface of the Ti29.44Cu46.72Ni7.88Zr7.6Hf8.4 BMG: (a) a 2D black and white PSEM graph; (b) and (c) 3D color PSEM graphs; and (d) the enlarged scale graph.
Fig. 2. PSEM graphs of the vein-like pattern in the fracture surface of the Ti31.4Cu43.8Ni8.8Zr7.6Hf8.4 BMG: (a) a 2D black and white PSEM graph; (b) and (c) 3D color PSEM graphs; and (d) the enlarged scale graph.
P. Li / Results in Physics 7 (2017) 1513–1515
Fig. 1a, the 2D PSEM graph is similar to the field-emission SEM graph. However, in the PSEM color figures in Fig. 1b, the intensities of different colors indicate the different regional levels. Fig. 1 shows the vein pattern of the PSEM graphs in the Ti29.44Cu46.72Ni7.88Zr7.6Hf8.4 sample, where Fig. 1b shows the 3D PSEM graph of the pattern in Fig. 1a. In the 3D PSEM graphs, the boundary of each vein pattern is a ‘‘projection.” The concentration of stress can occur in the boundaries of the vein patterns, where initial slip can also occur. The lines ‘‘1” and ‘‘2” used to calculate the height of ‘‘projection” and the width of each vein pattern, respectively, are marked in Fig. 1c. The width of approximately five veined patterns is exhibited in line ‘‘1”. The width of each pattern is approximately 10 lm. To show the width of the vein pattern in different directions, the angle between the lines ‘‘2” and ‘‘1” is approximately 100°. The width of each vein pattern is 8–10 lm in line ‘‘2”. Thus, the width of the vein patterns in the different directions is approximately 10 lm. The average height of ‘‘projection” is approximately 2 lm in lines ‘‘1” and ‘‘2.” The vein-like patterns of the PSEM graphs for the Ti31.4Cu43.8Ni8.8Zr7.6Hf8.4 BMG are shown in Fig. 2. As shown in Fig. 2b, the large vein-like patterns contain some smaller veinlike patterns, indicating that a ladder of vein patterns can exist. Fig. 2b contains fewer pink areas compared to Fig. 1b, indicating that the height of ‘‘projection” in the boundary of vein-like patterns in Fig. 2b is less than that in Fig. 1b. By measuring the line labeled ‘‘1” in Fig. 2b, we estimated the height of the ‘‘projection” to be approximately 0.8–1.1 lm, with an average height of ‘‘projection” of approximately 0.95 lm. In addition, the height of the pink areas is approximately 2 lm; they were not considered in the calculated average height because their proportion is very small. Thus, the average height of ‘‘projection” for the Ti31.4Cu43.8Ni8.8Zr7.6Hf8.4 BMG is approximately 0.95 lm, which is less than that for the Ti29.44Cu46.72Ni7.88Zr7.6Hf8.4 BMG. Because the plasticity of the Ti29.44Cu46.72Ni7.88Zr7.6Hf8.4 BMG was significantly greater than that of the Ti31.4Cu43.8Ni8.8Zr7.6Hf8.4 BMG, the height of ‘‘projection” at the boundary of the vein pattern can illustrate the plasticity of the BMGs. A greater plasticity leads to a greater average height of ‘‘projection” and vice versa. When the height of ‘‘projection” in the vein-like pattern is larger or smaller, the absorptive plastic
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work is also larger or smaller, indicating that the plasticity of the corresponding BMGs is larger or smaller, respectively. Thus, the height of ‘‘projection” in the vein-like pattern can reflect the degree of plasticity in a metallic glass. Conclusion In this paper, the relationship between the vein-like pattern and plasticity in Ti29.44Cu46.72Ni7.88Zr7.6Hf8.4 and Ti31.4Cu43.8Ni8.8Zr7.6Hf8.4 bulk metallic glasses was investigated. By observing the fracture morphology of samples using PSEM, we observed that a greater plasticity results in a greater average height of ‘‘projection” and that the smaller plasticity has the smaller average height of ‘‘projection”. When the height of ‘‘projection” in the vein-like pattern is larger or smaller, the absorptive plastic work is larger or smaller, indicating that the plasticity of the corresponding material is larger or smaller, respectively. We conclude that the height of ‘‘projection” in the vein pattern can reveal the degree of plasticity in Ti-Cu-Ni-Zr-Hf metallic glass. Acknowledgments P.Y. Li acknowledge the financial support from the special foundation of Education Department of Shaanxi Provincial (16JK1152), and the startup doctoral foundation of Shaanxi University of Technology (SLGKYQD2-22). References [1] [2] [3] [4] [5] [6] [7]
Fineberg J, Gross SP, Marder M, Swinney HL. Phys Rev Lett 1991;67:457. Ramanathan S, Fisher DS. Phys Rev Lett 1997;79:877. Bonamy D, Ravi-Chandar K. Phys Rev Lett 2004;93:099602. Gao M, Sun BA, Yuan CC, Ma J, Wang WH. Acta Mater 2012;60:6952. Wu FF, Zheng W, Deng JW, Qu DD, Shen J. Mater Sci Eng A 2012;541:199. Lowhaphandu P, Lewandowski JJ. Scripta Mater 1998;38:1811. Xi XK, Zhao DQ, Pan MX, Wang WH, Wu Y, Lewandowski JJ. Phys Rev Lett 2005;94:125510. [8] Wang G, Wang YT, Liu YH, Pan MX, Zhao DQ, Wang WH. Appl Phys Lett 2006;89:121909. [9] Sun BA, Tan J, Pauly S, Kühn U, Eckert J. J Appl Phys 2012;112:103533. [10] Li PY, Wang G, Ding D, Shen J. Mater Des 2014;53:145.
Contents lists available at ScienceDirect
Results in Physics journal homepage: www.journals.elsevier.com/results-in-physics
Relationship between vein-like pattern and plasticity in Ti–Cu–Ni–Zr–Hf bulk metallic glasses Peiyou Li School of Materials Science and Engineering, Shaanxi University of Technology, Hanzhong 723001, People’s Republic of China
a r t i c l e
i n f o
Article history: Received 24 March 2017 Received in revised form 9 April 2017 Accepted 10 April 2017 Available online 25 April 2017 Keywords: Ti-Cu-Ni-Zr-Hf Phenom scanning electron microscope Vein-like pattern Plasticity
a b s t r a c t The relationship between vein-like patterns and plasticity was investigated in Ti29.44Cu46.72Ni7.88Zr7.6Hf8.4 and Ti31.4Cu43.8Ni8.8Zr7.6Hf8.4 bulk metallic glasses. By observing the fracture morphology of the samples using a phenom scanning electron microscope (PSEM), we demonstrated that a large or small plasticity results in a large or small average height of ‘‘projection” in the vein-like patterns, respectively. The results indicate that, if the height of ‘‘projection” in the vein-like pattern is large or small, the absorptive plastic work is also large or small, in turn indicating that the plasticity of the corresponding metallic glasses is large or small, respectively. The height of ‘‘projection” in the vein-like pattern was determined to reveal the degree of plasticity in Ti-Cu-Ni-Zr-Hf metallic glasses. Ó 2017 The Author. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
Introduction The fracture surfaces of compressive metallic glasses (MGs) exhibit a complicated morphology. Because abundant fracture information is stored on the surface of fracture [1–5], investigation of the surface roughening morphology is an effective method for elucidating the fracture behavior and mechanism of a material [4]. Diverse patterns such as dimple structures [4,6,7], periodic corrugations [5,8], and river- and vein-like patterns [7,9] have been observed on the fracture surface of different MGs using twodimensional (2D) black and white scanning electron microscopy (SEM) images. However, the height and depth of diverse patterns cannot be shown in two-dimensional images. In this work, using a third-generation phenom scanning electron microscope (PSEM), we investigated the relationship between the ‘‘projection” of vein-like patterns and plasticity in Ti–Cu–Ni– Zr–Hf bulk metallic glasses (BMGs) is investigated from both scientific and commercial viewpoints because of their high strength and good plasticity [10]. The relationship between the absorptive plastic work and the plasticity of the corresponding material is also discussed.
Experimental procedure Ingots of Ti29.44Cu46.72Ni7.88Zr7.6Hf8.4 and Ti31.4Cu43.8Ni8.8Zr7.6Hf8.4 alloys with nominal composition were prepared by arc-melting a E-mail address: [email protected]
mixture of pure metal elements (with purities greater than 99.9%) in a titanium-gettered argon atmosphere. The ingots were re-melted at least four times to achieve chemical homogeneity and then suction cast into copper molds to form rod-shaped samples with a diameter of 2 mm. A cylindrical sample with a diameter of 2 mm and a height of approximately 4 mm was prepared from the as-cast rods for uniaxial compression tests. The compression tests were conducted at room temperature in a SANS 1500 compression testing machine. Two- and three-dimensional (3D) images for the fracture surfaces of the samples were acquired using a third-generation PSEM operated at an accelerating voltage of 15 kV.
Results and discussion In the 2D SEM map, the high plasticity is related to the formation of multiple shear bands. However, the relationship between the plasticity and the depth of vein patterns cannot be exhibited via two-dimensional SEM. On the basis of the limitations of 2D SEM imaging, we investigated the relationship between the plasticity and the depth of vein patterns using 3D SEM diagrams. To simplify the analysis, we selected the Ti29.44Cu46.72Ni7.88Zr7.6Hf8.4 sample with the largest plastic strain of 1.8% and the Ti31.4Cu43.8Ni8.8Zr7.6Hf8.4 sample with the smallest plastic strain of 0.3% for PSEM observation in four Ti-Cu-Ni-Zr-Hf BMGs from Ref. [10]. The PSEM graphs of the fracture surface of the Ti29.44Cu46.72Ni7.88Zr7.6Hf8.4 BMG are shown in Fig. 1. As shown in
http://dx.doi.org/10.1016/j.rinp.2017.04.012 2211-3797/Ó 2017 The Author. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
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Fig. 1. PSEM graphs of the vein-like pattern in the fracture surface of the Ti29.44Cu46.72Ni7.88Zr7.6Hf8.4 BMG: (a) a 2D black and white PSEM graph; (b) and (c) 3D color PSEM graphs; and (d) the enlarged scale graph.
Fig. 2. PSEM graphs of the vein-like pattern in the fracture surface of the Ti31.4Cu43.8Ni8.8Zr7.6Hf8.4 BMG: (a) a 2D black and white PSEM graph; (b) and (c) 3D color PSEM graphs; and (d) the enlarged scale graph.
P. Li / Results in Physics 7 (2017) 1513–1515
Fig. 1a, the 2D PSEM graph is similar to the field-emission SEM graph. However, in the PSEM color figures in Fig. 1b, the intensities of different colors indicate the different regional levels. Fig. 1 shows the vein pattern of the PSEM graphs in the Ti29.44Cu46.72Ni7.88Zr7.6Hf8.4 sample, where Fig. 1b shows the 3D PSEM graph of the pattern in Fig. 1a. In the 3D PSEM graphs, the boundary of each vein pattern is a ‘‘projection.” The concentration of stress can occur in the boundaries of the vein patterns, where initial slip can also occur. The lines ‘‘1” and ‘‘2” used to calculate the height of ‘‘projection” and the width of each vein pattern, respectively, are marked in Fig. 1c. The width of approximately five veined patterns is exhibited in line ‘‘1”. The width of each pattern is approximately 10 lm. To show the width of the vein pattern in different directions, the angle between the lines ‘‘2” and ‘‘1” is approximately 100°. The width of each vein pattern is 8–10 lm in line ‘‘2”. Thus, the width of the vein patterns in the different directions is approximately 10 lm. The average height of ‘‘projection” is approximately 2 lm in lines ‘‘1” and ‘‘2.” The vein-like patterns of the PSEM graphs for the Ti31.4Cu43.8Ni8.8Zr7.6Hf8.4 BMG are shown in Fig. 2. As shown in Fig. 2b, the large vein-like patterns contain some smaller veinlike patterns, indicating that a ladder of vein patterns can exist. Fig. 2b contains fewer pink areas compared to Fig. 1b, indicating that the height of ‘‘projection” in the boundary of vein-like patterns in Fig. 2b is less than that in Fig. 1b. By measuring the line labeled ‘‘1” in Fig. 2b, we estimated the height of the ‘‘projection” to be approximately 0.8–1.1 lm, with an average height of ‘‘projection” of approximately 0.95 lm. In addition, the height of the pink areas is approximately 2 lm; they were not considered in the calculated average height because their proportion is very small. Thus, the average height of ‘‘projection” for the Ti31.4Cu43.8Ni8.8Zr7.6Hf8.4 BMG is approximately 0.95 lm, which is less than that for the Ti29.44Cu46.72Ni7.88Zr7.6Hf8.4 BMG. Because the plasticity of the Ti29.44Cu46.72Ni7.88Zr7.6Hf8.4 BMG was significantly greater than that of the Ti31.4Cu43.8Ni8.8Zr7.6Hf8.4 BMG, the height of ‘‘projection” at the boundary of the vein pattern can illustrate the plasticity of the BMGs. A greater plasticity leads to a greater average height of ‘‘projection” and vice versa. When the height of ‘‘projection” in the vein-like pattern is larger or smaller, the absorptive plastic
1515
work is also larger or smaller, indicating that the plasticity of the corresponding BMGs is larger or smaller, respectively. Thus, the height of ‘‘projection” in the vein-like pattern can reflect the degree of plasticity in a metallic glass. Conclusion In this paper, the relationship between the vein-like pattern and plasticity in Ti29.44Cu46.72Ni7.88Zr7.6Hf8.4 and Ti31.4Cu43.8Ni8.8Zr7.6Hf8.4 bulk metallic glasses was investigated. By observing the fracture morphology of samples using PSEM, we observed that a greater plasticity results in a greater average height of ‘‘projection” and that the smaller plasticity has the smaller average height of ‘‘projection”. When the height of ‘‘projection” in the vein-like pattern is larger or smaller, the absorptive plastic work is larger or smaller, indicating that the plasticity of the corresponding material is larger or smaller, respectively. We conclude that the height of ‘‘projection” in the vein pattern can reveal the degree of plasticity in Ti-Cu-Ni-Zr-Hf metallic glass. Acknowledgments P.Y. Li acknowledge the financial support from the special foundation of Education Department of Shaanxi Provincial (16JK1152), and the startup doctoral foundation of Shaanxi University of Technology (SLGKYQD2-22). References [1] [2] [3] [4] [5] [6] [7]
Fineberg J, Gross SP, Marder M, Swinney HL. Phys Rev Lett 1991;67:457. Ramanathan S, Fisher DS. Phys Rev Lett 1997;79:877. Bonamy D, Ravi-Chandar K. Phys Rev Lett 2004;93:099602. Gao M, Sun BA, Yuan CC, Ma J, Wang WH. Acta Mater 2012;60:6952. Wu FF, Zheng W, Deng JW, Qu DD, Shen J. Mater Sci Eng A 2012;541:199. Lowhaphandu P, Lewandowski JJ. Scripta Mater 1998;38:1811. Xi XK, Zhao DQ, Pan MX, Wang WH, Wu Y, Lewandowski JJ. Phys Rev Lett 2005;94:125510. [8] Wang G, Wang YT, Liu YH, Pan MX, Zhao DQ, Wang WH. Appl Phys Lett 2006;89:121909. [9] Sun BA, Tan J, Pauly S, Kühn U, Eckert J. J Appl Phys 2012;112:103533. [10] Li PY, Wang G, Ding D, Shen J. Mater Des 2014;53:145.