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Selective laser melting of CuZr-based metallic glass composites
Journal Pre-proofs Selective laser melting of CuZr-based metallic glass composites Xiaodong Gao, Zhaolin Liu, Jianhui Li, Enfu Liu, Chengming Yue, Kun Zhao, Guang Yang PII: DOI: Reference:
S0167-577X(19)31355-2 https://doi.org/10.1016/j.matlet.2019.126724 MLBLUE 126724
To appear in:
Materials Letters
Received Date: Revised Date: Accepted Date:
31 July 2019 9 September 2019 21 September 2019
Please cite this article as: X. Gao, Z. Liu, J. Li, E. Liu, C. Yue, K. Zhao, G. Yang, Selective laser melting of CuZrbased metallic glass composites, Materials Letters (2019), doi: https://doi.org/10.1016/j.matlet.2019.126724
This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
© 2019 Published by Elsevier B.V.
Selective laser melting of CuZr-based metallic glass composites Xiaodong Gao, Zhaolin Liu, Jianhui Li, Enfu Liu, Chengming Yue, Kun Zhao*, Guang Yang* Hebei University of Science and Technology, 26 Yuxiang Road, Shijiazhuang 050018, China
ABSTRACT: Crack free CuZr-based metallic glass composites are fabricated by selective laser melting. The structure is examined by X-ray diffraction and scanning electron microscopy. The compression properties of the CuZr-based metallic glass composites are tested by universal testing machine. The results show that B2 CuZr phases are embedded in glassy matrix. The microstructure is sensitive to processing parameters. The composites samples show high fracture strength and anisotropic mechanical performance. Keywords: Amorphous materials; Metallic composites; Deformation and fracture; Additive manufacture; Selective laser melting 1. Introduction Metallic glasses have much higher yield strength compared with their crystalline counterparts [1, 2]. The unique mechanical performances make metallic glass and its composite attractive for some industrial applications[3, 4]. Although metallic glasses are inherently strong, monolithic metallic glasses hardly show tension plasticity.
Corresponding authors at: Hebei University of Science and Technology, 26 Yuxiang Road,
Shijiazhuang 050018, China. E-mail addresses: [email protected] (Zhaolin Liu), [email protected] (Kun Zhao), [email protected] (Guang Yang).
Strain-softening behavior and room-temperature brittleness have been the Achilles’ heel for their real applications. It is worth noting that metallic glass matrix composite is an effective solution to alleviate the embrittlement [5-7]. The CuZr-based in-situ metallic glass matrix composites traditionally fabricated by copper mold cast method have excellent mechanical performance [8-10]. However, the critical cooling rate has strong constraint on their size and shape, which limits their range of application. Additive manufactures of metallic glasses have been reported in recent years [11-15]. The intriguing advantage of additive manufacture is the breakthrough of size limitation. Crystalline phase usually appears in the heat affected zone [16]. In most cases, the precipitated crystalline phase would weaken the strength and compression plasticity of metallic glasses. However, the CuZr-based metallic glasses do not follow that trend [8-10]. Our primary study shows crack free CuZr-based metallic glass composites can be successfully fabricated by selective laser melting (SLM). B2 CuZr phases are precipitated in the glassy matrix, and the samples show high fracture strength. 2. Experimental details The powders with nominal composition Cu46Zr47Al6Co1 (at.%) were produced by inert gas atomization. The distribution of particle size was analyzed by BT-9300ST laser particle size analyzer. The SLM experiment was performed by commercial SLM machine Renishaw AM250. The forming chamber was vacuumed and protected by argon gas with oxygen content below 500 ppm. The layer thickness was 50 μm. The power and diameter of the laser were 200 W and 75 μm, respectively. The laser
exposure time was 100 μs, with a halting time of 10 μs. The point distance along the scanning line was 110 μm. The hatch spacing between scanning lines was 60 μm and 85 μm, respectively. Crack free specimens with dimensions of 10 mm × 10 mm × 5 mm were fabricated by SLM. The microstructure of the samples was analyzed by X-ray diffraction (XRD, Rigaku D/MAX-2500) and scanning electron microscopy (SEM, TESCAN VEGA 3). Cuboid blocks with an aspect ratio of 2:1 were cut from the samples for compression test. The mechanical properties were measured under quasi-static uniaxial compression with a strain rate of 1 × 10−4 s−1 using a universal test machine (CMT5105) at room temperature. 3. Results and discussion The powders for SLM are shown in Fig. 1(a). The SEM image shows that most of the powders are spherical shape with diameter of several tens of micrometers. The spherical shape of the powder with smooth surface is due to surface tension when produced by gas atomization, and it is suitable for SLM. The distribution of particle size is shown in Fig. 1(b). The D10, D50 and D90 are 22.06 μm, 37.78 μm and 63.31 μm, respectively. Fig. 1(c) is a photograph of the alloys fabricated by SLM. The fabricated alloys are attached to zirconium substrate firmly, and no cracks are found on the surface of the samples. The inset shows the specimens cut from the fabricated alloys for structural and mechanical tests. Fig. 1(d) shows the low magnification SEM image of the cross section of one sample. No cracks are found in the interior of the sample.
Fig. 1. (a) SEM image of the powders for SLM, (b) distribution of the particle size, (c) photograph of the alloys fabricated by SLM, the inset shows specimens cut from the fabricated alloys, and (d) SEM image of the cross section
Fig. 2(a) shows the XRD patterns of the SLM alloys. The alloys exhibit distinct diffraction pattern typical of metallic glass composites. The crystalline peaks are identified as B2 CuZr phases, while the broad halo indicates the existence of metallic glass matrix. The height of crystalline peak implies that the shape and percentage of precipitated B2 CuZr phase is sensitive to the hatch spacing. Fig. 2(b) is the SEM image of the cross-section of the sample with a hatch spacing of 85 μm. Some micrometer-sized crystalline phases are embedded in the glassy matrix. Fig. 2(c) shows the SEM image of the cross-section of the sample with a hatch spacing of 60 μm. The size of crystalline phase is larger, which is consistent with the XRD results. Previous study shows that the crystalline phases are precipitated in the heat affected zone [16]. If the hatch spacing is narrow, the heat affected zone may overlap in adjacent scanning lines. Some micrometer-sized crystalline phases already exit in the
overlapping area for the latter laser scanning. The crystalline phases grow and connect to form the irregular shape of the crystalline phase in the latter laser scanning process.
Fig. 2. (a) XRD patterns of the fabricated samples, (b) SEM image of the sample with a hatch spacing of 85 μm, and (c) SEM image of the sample with a hatch spacing of 60 μm.
The composite structure should have excellent mechanical properties if the CuZr-based samples were prepared by conventional copper mould cast method [8-10]. However, the mechanical performance of the samples made by selective laser melting is sensitive to the processing parameters such as hatching space. Meanwhile, the loading direction also plays an important role on the fracture strength of the samples. Fig. 3(a) shows the stress-strain curves of the alloys with a hatch spacing of
60 μm. The dashed lines are straight lines for guiding the eyes. The fracture strength of the sample is 0.94 GPa along the loading direction perpendicular to the layer when it is made, and the stress-strain curve deviates from linearity at the end. On the contrary, the fracture strength is lower when the sample is loaded parallel to the layer, and the stress-strain curve does not deviate from linearity. Fig. 3(b) shows the stress-strain curves of the alloys with a hatch spacing of 85 μm. The fracture strength of the sample is 0.93 GPa along the loading direction perpendicular to the layer when it is made, while the fracture strength becomes 0.67 GPa when the loading is parallel to the layer. It is remarkable that some peculiar deformation occurs at the presumably elastic region according to the stress-strain curve with loading parallel to the layer. It has been reported that thermal stress accumulates layer after layer in SLM [17]. In our study, the samples usually break along the layer direction if the samples are loaded parallel to layer. It is possible that the abnormal stress-strain curve is associated with the release of internal stress between layers.
Fig. 3. (a) Stress-strain curves of the alloys with a hatch spacing of 60 μm and (b) stress-strain curves of the alloys with a hatch spacing of 85 μm.
4. Conclusion Crack free CuZr-based metallic glass composites can be successfully fabricated by
SLM. B2 CuZr phases are precipitated in the glassy matrix. The microstructure and mechanical performance of the samples are sensitive to processing parameters. Our work demonstrates that SLM can be used to produce in-situ crystalline phase reinforced metallic glass composites. The mechanical quality of the metallic glass composites can be further improved by adjusting the processing parameters and rejuvenation treatment. Declaration of interests The authors declare that they have no known conflict of interest that could have appeared to influence the work reported in this paper. Acknowledgments This work was supported by the National Natural Science Foundation of China (Grant No. 51201057), the Five Platform Open Funds of Hebei University of Science and Technology (Grant Nos. 2018PT31 and 2018PT32), and the Undergraduates Innovation Program of Hebei Univeristy of Science and Technology (Grant No. 2019190). References [1] W.H. Wang, Prog. Mater. Sci. 57 (2012) 487-656. [2] J. Wang, R. Li, N. Hua, T. Zhang, J. Mater. Res. 26 (19) (2011) 2072-2079. [3] T.C. Hufnagel, C.A. Schuh, M.L. Falk, Acta Mater. 109 (2016) 375-393. [4] H.F. Li, Y.F. Zheng, Acta Biom. 36 (2016) 1-20. [5] D.C. Hofmann, J.Y. Suh, A. Wiest, G. Duan, M.L. Lind, M.D. Demetriou, W.L. Johnson, Nature 451 (2008) 1085-1089.
[6] J. Qiao, H. Jia, P.K. Liaw, Mater. Sci. Eng. R 100 (2016) 1-69. [7] Y. Wu, H. Wang, X.J. Liu, X.H. Chen, X.D. Hui, Y. Zhang, Z.P. Lu, J. Mater. Sci. Technol. 30 (6) (2014) 566-575. [8] W. Song, Y. Wu, H. Wang, X. Liu, H. Chen, Z. Cuo, Z. Lu, Adv. Mater. 28 (2016) 8156-8161. [9] Y.S. Qin, X.L. Han, K.K. Song, Y.H. Tian, C.X. Peng, L. Wang, B.A. Sun, G. Wang, I. Kaban, J. Eckert. Sci. Rep. 7 (2017) 42518. [10] S. Pauly, S. Gorantla, G. Wang, U. Kuhn, J. Eckert, Nature Mater. 9 (2010) 473-477. [11] N. Li, J. Zhang, W. Xing, D. Ouyang, L. Liu, Mater. Des. 143 (2018) 285-296. [12] H.Y. Jung, S.J. Choi, K.G. Prashanth, M. Stoica, S. Scudino, S. Yi, U. Kuhn, D.H. Kim, K.B. Kim, J. Eckert, Mater. Des. 86 (2015) 703-708. [13] X.P. Li, M.P. Roberts, S.O’Keeffe, T.B. Sercombe, Mater. Des. 12 (2016) 217-226. [14] D. Ouyang, N. Li, W. Xing, J. Zhang, L. Liu, Intermetallic 90 (2017) 128-134. [15] Y. Shen, Y. Li, C. Chen, H.L. Tsai, Mater. Des. 117 (2017) 213-222. [16] Y. Lu, H. Zhang, H. Li, H. Xu, G. Huang, Z. Qin, X. Lu, J. Non-cryst. Solids 461 (2017) 12-17. [17] X.P. Li, C.W. Kang, H. Huang, T.B. Sercombe, Mater. Des. 63 (2014) 407-411.
1. CuZr-based metallic glass composites can be fabricated by selective laser melting 2. B2 CuZr phases are precipitated in the glassy matrix 3. Microstructures of the composites are sensitive to processing parameters 4. The alloys show high fracture strength and anisotropic mechanical performance 5. SLM can produce in-situ crystalline phase reinforced metallic glass composites
S0167-577X(19)31355-2 https://doi.org/10.1016/j.matlet.2019.126724 MLBLUE 126724
To appear in:
Materials Letters
Received Date: Revised Date: Accepted Date:
31 July 2019 9 September 2019 21 September 2019
Please cite this article as: X. Gao, Z. Liu, J. Li, E. Liu, C. Yue, K. Zhao, G. Yang, Selective laser melting of CuZrbased metallic glass composites, Materials Letters (2019), doi: https://doi.org/10.1016/j.matlet.2019.126724
This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
© 2019 Published by Elsevier B.V.
Selective laser melting of CuZr-based metallic glass composites Xiaodong Gao, Zhaolin Liu, Jianhui Li, Enfu Liu, Chengming Yue, Kun Zhao*, Guang Yang* Hebei University of Science and Technology, 26 Yuxiang Road, Shijiazhuang 050018, China
ABSTRACT: Crack free CuZr-based metallic glass composites are fabricated by selective laser melting. The structure is examined by X-ray diffraction and scanning electron microscopy. The compression properties of the CuZr-based metallic glass composites are tested by universal testing machine. The results show that B2 CuZr phases are embedded in glassy matrix. The microstructure is sensitive to processing parameters. The composites samples show high fracture strength and anisotropic mechanical performance. Keywords: Amorphous materials; Metallic composites; Deformation and fracture; Additive manufacture; Selective laser melting 1. Introduction Metallic glasses have much higher yield strength compared with their crystalline counterparts [1, 2]. The unique mechanical performances make metallic glass and its composite attractive for some industrial applications[3, 4]. Although metallic glasses are inherently strong, monolithic metallic glasses hardly show tension plasticity.
Corresponding authors at: Hebei University of Science and Technology, 26 Yuxiang Road,
Shijiazhuang 050018, China. E-mail addresses: [email protected] (Zhaolin Liu), [email protected] (Kun Zhao), [email protected] (Guang Yang).
Strain-softening behavior and room-temperature brittleness have been the Achilles’ heel for their real applications. It is worth noting that metallic glass matrix composite is an effective solution to alleviate the embrittlement [5-7]. The CuZr-based in-situ metallic glass matrix composites traditionally fabricated by copper mold cast method have excellent mechanical performance [8-10]. However, the critical cooling rate has strong constraint on their size and shape, which limits their range of application. Additive manufactures of metallic glasses have been reported in recent years [11-15]. The intriguing advantage of additive manufacture is the breakthrough of size limitation. Crystalline phase usually appears in the heat affected zone [16]. In most cases, the precipitated crystalline phase would weaken the strength and compression plasticity of metallic glasses. However, the CuZr-based metallic glasses do not follow that trend [8-10]. Our primary study shows crack free CuZr-based metallic glass composites can be successfully fabricated by selective laser melting (SLM). B2 CuZr phases are precipitated in the glassy matrix, and the samples show high fracture strength. 2. Experimental details The powders with nominal composition Cu46Zr47Al6Co1 (at.%) were produced by inert gas atomization. The distribution of particle size was analyzed by BT-9300ST laser particle size analyzer. The SLM experiment was performed by commercial SLM machine Renishaw AM250. The forming chamber was vacuumed and protected by argon gas with oxygen content below 500 ppm. The layer thickness was 50 μm. The power and diameter of the laser were 200 W and 75 μm, respectively. The laser
exposure time was 100 μs, with a halting time of 10 μs. The point distance along the scanning line was 110 μm. The hatch spacing between scanning lines was 60 μm and 85 μm, respectively. Crack free specimens with dimensions of 10 mm × 10 mm × 5 mm were fabricated by SLM. The microstructure of the samples was analyzed by X-ray diffraction (XRD, Rigaku D/MAX-2500) and scanning electron microscopy (SEM, TESCAN VEGA 3). Cuboid blocks with an aspect ratio of 2:1 were cut from the samples for compression test. The mechanical properties were measured under quasi-static uniaxial compression with a strain rate of 1 × 10−4 s−1 using a universal test machine (CMT5105) at room temperature. 3. Results and discussion The powders for SLM are shown in Fig. 1(a). The SEM image shows that most of the powders are spherical shape with diameter of several tens of micrometers. The spherical shape of the powder with smooth surface is due to surface tension when produced by gas atomization, and it is suitable for SLM. The distribution of particle size is shown in Fig. 1(b). The D10, D50 and D90 are 22.06 μm, 37.78 μm and 63.31 μm, respectively. Fig. 1(c) is a photograph of the alloys fabricated by SLM. The fabricated alloys are attached to zirconium substrate firmly, and no cracks are found on the surface of the samples. The inset shows the specimens cut from the fabricated alloys for structural and mechanical tests. Fig. 1(d) shows the low magnification SEM image of the cross section of one sample. No cracks are found in the interior of the sample.
Fig. 1. (a) SEM image of the powders for SLM, (b) distribution of the particle size, (c) photograph of the alloys fabricated by SLM, the inset shows specimens cut from the fabricated alloys, and (d) SEM image of the cross section
Fig. 2(a) shows the XRD patterns of the SLM alloys. The alloys exhibit distinct diffraction pattern typical of metallic glass composites. The crystalline peaks are identified as B2 CuZr phases, while the broad halo indicates the existence of metallic glass matrix. The height of crystalline peak implies that the shape and percentage of precipitated B2 CuZr phase is sensitive to the hatch spacing. Fig. 2(b) is the SEM image of the cross-section of the sample with a hatch spacing of 85 μm. Some micrometer-sized crystalline phases are embedded in the glassy matrix. Fig. 2(c) shows the SEM image of the cross-section of the sample with a hatch spacing of 60 μm. The size of crystalline phase is larger, which is consistent with the XRD results. Previous study shows that the crystalline phases are precipitated in the heat affected zone [16]. If the hatch spacing is narrow, the heat affected zone may overlap in adjacent scanning lines. Some micrometer-sized crystalline phases already exit in the
overlapping area for the latter laser scanning. The crystalline phases grow and connect to form the irregular shape of the crystalline phase in the latter laser scanning process.
Fig. 2. (a) XRD patterns of the fabricated samples, (b) SEM image of the sample with a hatch spacing of 85 μm, and (c) SEM image of the sample with a hatch spacing of 60 μm.
The composite structure should have excellent mechanical properties if the CuZr-based samples were prepared by conventional copper mould cast method [8-10]. However, the mechanical performance of the samples made by selective laser melting is sensitive to the processing parameters such as hatching space. Meanwhile, the loading direction also plays an important role on the fracture strength of the samples. Fig. 3(a) shows the stress-strain curves of the alloys with a hatch spacing of
60 μm. The dashed lines are straight lines for guiding the eyes. The fracture strength of the sample is 0.94 GPa along the loading direction perpendicular to the layer when it is made, and the stress-strain curve deviates from linearity at the end. On the contrary, the fracture strength is lower when the sample is loaded parallel to the layer, and the stress-strain curve does not deviate from linearity. Fig. 3(b) shows the stress-strain curves of the alloys with a hatch spacing of 85 μm. The fracture strength of the sample is 0.93 GPa along the loading direction perpendicular to the layer when it is made, while the fracture strength becomes 0.67 GPa when the loading is parallel to the layer. It is remarkable that some peculiar deformation occurs at the presumably elastic region according to the stress-strain curve with loading parallel to the layer. It has been reported that thermal stress accumulates layer after layer in SLM [17]. In our study, the samples usually break along the layer direction if the samples are loaded parallel to layer. It is possible that the abnormal stress-strain curve is associated with the release of internal stress between layers.
Fig. 3. (a) Stress-strain curves of the alloys with a hatch spacing of 60 μm and (b) stress-strain curves of the alloys with a hatch spacing of 85 μm.
4. Conclusion Crack free CuZr-based metallic glass composites can be successfully fabricated by
SLM. B2 CuZr phases are precipitated in the glassy matrix. The microstructure and mechanical performance of the samples are sensitive to processing parameters. Our work demonstrates that SLM can be used to produce in-situ crystalline phase reinforced metallic glass composites. The mechanical quality of the metallic glass composites can be further improved by adjusting the processing parameters and rejuvenation treatment. Declaration of interests The authors declare that they have no known conflict of interest that could have appeared to influence the work reported in this paper. Acknowledgments This work was supported by the National Natural Science Foundation of China (Grant No. 51201057), the Five Platform Open Funds of Hebei University of Science and Technology (Grant Nos. 2018PT31 and 2018PT32), and the Undergraduates Innovation Program of Hebei Univeristy of Science and Technology (Grant No. 2019190). References [1] W.H. Wang, Prog. Mater. Sci. 57 (2012) 487-656. [2] J. Wang, R. Li, N. Hua, T. Zhang, J. Mater. Res. 26 (19) (2011) 2072-2079. [3] T.C. Hufnagel, C.A. Schuh, M.L. Falk, Acta Mater. 109 (2016) 375-393. [4] H.F. Li, Y.F. Zheng, Acta Biom. 36 (2016) 1-20. [5] D.C. Hofmann, J.Y. Suh, A. Wiest, G. Duan, M.L. Lind, M.D. Demetriou, W.L. Johnson, Nature 451 (2008) 1085-1089.
[6] J. Qiao, H. Jia, P.K. Liaw, Mater. Sci. Eng. R 100 (2016) 1-69. [7] Y. Wu, H. Wang, X.J. Liu, X.H. Chen, X.D. Hui, Y. Zhang, Z.P. Lu, J. Mater. Sci. Technol. 30 (6) (2014) 566-575. [8] W. Song, Y. Wu, H. Wang, X. Liu, H. Chen, Z. Cuo, Z. Lu, Adv. Mater. 28 (2016) 8156-8161. [9] Y.S. Qin, X.L. Han, K.K. Song, Y.H. Tian, C.X. Peng, L. Wang, B.A. Sun, G. Wang, I. Kaban, J. Eckert. Sci. Rep. 7 (2017) 42518. [10] S. Pauly, S. Gorantla, G. Wang, U. Kuhn, J. Eckert, Nature Mater. 9 (2010) 473-477. [11] N. Li, J. Zhang, W. Xing, D. Ouyang, L. Liu, Mater. Des. 143 (2018) 285-296. [12] H.Y. Jung, S.J. Choi, K.G. Prashanth, M. Stoica, S. Scudino, S. Yi, U. Kuhn, D.H. Kim, K.B. Kim, J. Eckert, Mater. Des. 86 (2015) 703-708. [13] X.P. Li, M.P. Roberts, S.O’Keeffe, T.B. Sercombe, Mater. Des. 12 (2016) 217-226. [14] D. Ouyang, N. Li, W. Xing, J. Zhang, L. Liu, Intermetallic 90 (2017) 128-134. [15] Y. Shen, Y. Li, C. Chen, H.L. Tsai, Mater. Des. 117 (2017) 213-222. [16] Y. Lu, H. Zhang, H. Li, H. Xu, G. Huang, Z. Qin, X. Lu, J. Non-cryst. Solids 461 (2017) 12-17. [17] X.P. Li, C.W. Kang, H. Huang, T.B. Sercombe, Mater. Des. 63 (2014) 407-411.
1. CuZr-based metallic glass composites can be fabricated by selective laser melting 2. B2 CuZr phases are precipitated in the glassy matrix 3. Microstructures of the composites are sensitive to processing parameters 4. The alloys show high fracture strength and anisotropic mechanical performance 5. SLM can produce in-situ crystalline phase reinforced metallic glass composites