- Email: [email protected]
wire feed
Physica E 81 (2016) 44–48
Contents lists available at ScienceDirect
Physica E journal homepage: www.elsevier.com/locate/physe
Laser fabrication nanocrystalline coatings using simultaneous powders/wire feed Jianing Li a,n, Tongguang Zhai a,b, Yuanbin Zhang a, Feihu Shan c, Peng Liu a, Guocheng Ren a a
School of Materials Science and Engineering, Shandong Jianzhu University, Fengming Road #1000, Jinan 250101, PR China Department of Chemical and Materials Engineering, University of Kentucky, Lexington, KY 40506, USA c Beijing Aeronautical Manufacturing Technology Research Institute, Beijing 100024, PR China b
H I G H L I G H T S
Simultaneously feeding TC17 wire and Stellite 20–Si3N4–TiC–Sb mixed powders formed composites. Sb addition in laser molten pool was favorable to the formations of UNs. UNs were intertwined with amorphous, leading the yarn-shape materials to be produced. Ti entered into molten pool from the wire and TA1, which may react with Si or N.
art ic l e i nf o
a b s t r a c t
Article history: Received 17 January 2016 Received in revised form 12 February 2016 Accepted 16 February 2016 Available online 18 February 2016
Laser melting deposition (LMD) fabrication is used to investigate feasibilty of simultaneously feeding TC17 wire and the Stellite 20–Si3N4–TiC–Sb mixed powders in order to increase the utilization ratio of materials and also quality of LMD composite coatings on the TA1 substrate. SEM images indicated that such LMD coating with metallurgical joint to substrate was formed free of the obvious defects. Lots of the ultrafine nanocrystals (UNs) were produced, which distributed uniformly in some coating matrix location, retarding growth of the ceramics in a certain extent; UNs were intertwined with amorphous, leading the yarn-shape materials to be produced. Compared with substrate, an improvement of wear resistance was achieved for such LMD coating. & 2016 Elsevier B.V. All rights reserved.
Keywords: Metal-matrix composites (MMCs) Surface properties Nanocrystalline materials Lasers
1. Introduction Direct LMD fabrication is a novel manufacturing technique developed about a decade ago which can directly fabricate 3D near net shape and fully dense components from metal powders in one step [1,2]. During such fabrication, the powder is fed at a controlled rate into the focal point of a laser where individual particles are melted as the movement of the laser follows the path defined by a CAD file of a component [3]. Recently, nano-composite coatings have become very popular because of their high toughness and stiffness along with the superior hardness and wear properties; amorphous alloys have attracted increasing attention because of their excellent properties, such as high hardness, corrosion and wear resistance, etc. [4,5]. Laser fabrication is a promising method n
Corresponding author. E-mail address: [email protected] (J.N. Li).
http://dx.doi.org/10.1016/j.physe.2016.02.014 1386-9477/& 2016 Elsevier B.V. All rights reserved.
to prepare the amorphous-nanocrystals reinforced coatings on metals substrate, improving the surface performance of metals substrate. In the last few years, lots of the effects have focused mainly on the powder feed laser deposition, while less work has been carried out on the microstructure performance of the simultaneous mixed powders and wire feeding laser deposited composites. The problem of single powders feed laser deposition is that low capture rate of the powders (10–30%), leads to wastage of the scattered powders (i.e. 90–70% of the feedstock) [6]. Through experimental work, it was confirmed that simultaneous LMD of the Stellite 20–Si3N4–TiC–Sb mixed powders and TC17 wire on titanium alloy can form the wear resistance amorphousnanocrystalline composite coatings. In this study, LMD fabrication is used to investigate the feasibilty of simultaneously feeding wire and mixed powders in order to increase the utilization ratio of materials and the quality of the laser fabricated composite coatings. Laser wire deposition technology will have a great application potential in industry fabrication fields.
J.N. Li et al. / Physica E 81 (2016) 44–48
Fig. 1. Schematic of direct LMD with simultaneous mixed powders and wire feed.
2. Experimental A LMD technique was conducted on a YAG (HL 3006D) laser materials processing system equipped with four-axis computer numerical controlled (CNC) laser materials processing machine under the vacuum environment, coaxial powder feeding device (DPSF-3) were employed to melt surfaces of samples; a CNCcontrolled wire feed system, including a precision wire feed nozzle
45
developed in-house, was used which can deliver wires with a diameter equal to or large than 0.4 mm. Materials used to be substrate: TA1 titanium alloy samples (10 mm 10 mm 32 mm) for wear test, or samples (10 mm 10 mm 10 mm) for microstructure analysis, chemical compositions (wt%) of TA1: 0.3Fe, 0.15Si, 0.1C, 0.05N, 0.015H and bal. Ti. Samples surfaces were ground with emery paper to remove the oxide scale, and rinsed with alcohol before a LMD process. The TC17 wire was used in this experiment, chemical compositions (wt%) of TC17: 4.60Al, 1.72Sn, 1.91Zr, 4.01Mo, 3.81Cr, 0.137O and bal. Ti; the powders mixture of Stellite 20 (Z99.5% purity, 50– 150 μm), Si3N4 ( Z99.5% purity, 50–150 μm), TiC ( Z99.5% purity, 50–150 μm), and Sb (Z99.5% purity, 5–50 μm) were used for a LMD technique. Compositions (wt%) of 80Stellite 20–7Si3N4 10TiC–3Sb were used to deposit on a TA1 alloy by a LMD process, chemical compositions (wt%) of Stellite 20: 2.45C, 32.50Cr, 1.00Si, 17.00W, 3.00Fe, 1.000Mo, 3.00Ni, bal. Co. Laser power¼1.8 kW, scanning velocity¼ 5–11.0 mm/s, powder feed rate¼15 g/min, wire feed rate¼5 mm/s, wire diameter¼ 1 mm and laser beam diameter¼4 mm, and an overlap of 30% between successive tracks was selected. Whole experiment process was in progress in an Ar environment box. During the LMD process, the substrate was irradiated by laser beam while the powders mixture and wire were also sent to the laser molten pool simultaneously, forming the composite coating (see Fig. 1). Microstructural morphologies of such LMD composite coating were analyzed by means of a LEO 1525 scanning electron microscope (SEM) and a Titan 80–300 high resolution transmission
Fig. 2. SEM images of LMD coating: (a) bond zone; (b) middle-coating; (c) UNs; (d) dendrites.
46
J.N. Li et al. / Physica E 81 (2016) 44–48
Fig. 3. Images (SEM/HRTEM) of this LMD coating: (a) eutectics; (b) yarn-shape materials; (c) eutectics in interface; (d) HRTEM image of middle-coating.
electron microscope (HRTEM); wear properties of such coating were tested by a WMM-W1 disc wear tester, the wear volume losses were measured interval every 10 min; the rotational speed of the wear tester was 425 r/min.
3. Results and analysis 3.1. SEM and HRTEM analysis As shown in Fig. 2a, there were the interdendritic lamellar eutectic phases made up mainly of Ni, Co and small amounts of other chemical elements in bottom of the LMD composite coating with a metallurgical combination with a TA1 substrate free of the obvious defects. It was noted that the fine block-shape precipitates were dispersed in the middle-coating (see Fig. 2b). Lots of N were released from Si3N4 during a LMD process, which were able to react with TiC in laser molten pool, forming the Ti(CN) block-shape strengthening phase [7]. It was also observed that lots of UNs were produced, which distributed uniformly in some location of middle-coating matrix (see Fig. 2c). The fact that the Sb addition in laser molten pool was favorable to the formations of UNs in such laser-treated coatings. Such nano-phase were formed via a dissolution/precipitation mechanism by means of the heterogeneous nucleation of nano nuclei and the subsequent grain grow. The effective crystal development of nano nuclei was significantly restricted due to insufficient time of existence time of molten pool for grain growth to occur, hence favorable ultrafine nano structure of the reinforcing phases was retained [8].
In addition, due to an uneven energy distribution of the laser molten pool, TiC in some location absorbed enough energy from the laser beam and grew in the dendrites (see Fig. 2d); moreover, due to addition of the TC17 wire and the dilution effect, lots of Ti entered into the molten pool from the wire and substrate, which may react with Si or N those released from the Si3N4, forming Ti-Si eutectics or TiN, respectively. Investigations [9] indicated that TiN may also grew in the dendrites in some sufficient locations of molten pool; further, as mentioned previously, the Sb addtion promoted lots of UNs to be produced, which may retard growth of the ceramics, such as TiN or TiC, etc. [10]. Thus, those ceramics exhibited fine microstructure. As shown in Fig. 3a, the eutectics were produced in the matrix of middle-coating, even a large quantity of UNs were observed attached to them. Usually, the melting point of alloy is lower than that of pure metal, and the melting point of liquid alloying lowest when the liquid alloying is closed to the eutectics elements, favoring the formation of amorphous phase [8]; it was noted that the yarn-shape materials without the obvious structures were obtained in such coating (see Fig. 3b). It was speculated that UNs were intertwined with amorphous, leading the yarn-shape materials to be produced; in addition, the eutectics were also observed in an interface of such yarn-shape materials (see Fig. 3c), such structure may strongly modify the wear and high temperature properties of the Ti-Al/Ti-Co intermetallics matrix. Fig. 3d indicated that the fine crystalline phases were engulfed by amorphous phases. It was speculate that UNs were intertwined with the amorphous, leading the yarn-shape materials to be produced; further, UNs may have a high interface energy, which became the
J.N. Li et al. / Physica E 81 (2016) 44–48
47
Fig. 4. Wear pattern and images of worn surface of LMD coating/TA1: (a) Wear pattern; (b) worn surface of TA1; (c) worn surface of LMD sample; (d) the etched worn surface of LMD sample.
driving force of the atomic motions, favoring formation of a compact fine structure [11]. 3.2. Wear properties Fig. 4a indicated that when the load was 10 kg, the wear volume losses of TA1 and the LMD coating increased with prolongation of the wear sliding time. The test results indicated that the wear volume loss of the such LMD coating was approximately 1/6 of TA1. Better wear resistance of such coating was mainly ascribed to the actions of the phase constituent, the compact microstructure and the solid solution/nanocrystals-amorphous strengthening. As shown in Fig. 4b and c, under the dry-sliding wear test, worn surface of LMD sample was more smooth than that of substrate, the adhesion patches and deep plowing grooves were existence. The fact that the formation of smooth worn surface of LMD sample was also mainly ascribed to the actions of the fine grain, the solid solution, amorphous-nanocrystalline and hard phases strengthening; for instence, the fine grain strengthening of the Ti(CN) precipitates, the solid solution strengthening of Si and Cr in γ-Co, the Fe base amorphous strengthening, etc. Under the action of the pinning effect of the precipitates, such as TiC and Ti (CN), the counterpart should overcome the hinders of these fine and dense precipitates, preventing formations of the deep plowing grooves during the sliding wear process [12,13]. As shown in Fig. 4d, lots of the fine precipitates were present in the etched worn surface of the LMD sample. The productions of these fine precipitates were beneficial in formation of smooth
surface. The fact that the moderate growth dispersal fine particles or fine precipitates may withstand external normal load better, which showed the excellent properties of the plasticity, wear and toughness, favoring an improvement of wear resistance, forming a smooth worn surface.
4. Conclusions In summary, composites of TC17 containing different volume fractions of Stellite 20–Si3N4–TiC–Sb were manufactured using a LMD technique. TC17 wire and the Stellite 20–Si3N4–TiC–Sb mixed powders were fed into the laser molten pool on TA1 titanium alloy substrate simultaneously. Due to the addition of the TC17 wire and the dilution effect, lots of Ti entered into the molten pool from the wire and TA1 substrate, which may react with Si or N those released from the Si3N4, forming the Ti-Si eutectics or TiN, respectively. Such LMD coating with metallurgical joint to substrate was formed free of the obvious defects. Sb addition in laser molten pool was favorable to the formation of the UNs in the laser-treated coatings; lots of UNs were produced, which distributed uniformly in some location of the coating matrix, retarding growth of the ceramics in a certain extent. UNs were intertwined with amorphous, leading the yarn-shape materials to be produced. When load was 10 kg, the wear volume loss of the such LMD coating was approximately 1/6 of TA1 after 10 min wear test.
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J.N. Li et al. / Physica E 81 (2016) 44–48
Acknowledgments This project is supported by National Natural Science Foundation of China (Grant no. 51505257).
References [1] K.I. Schwendner, R. Banerjee, P.C. Collins, C.A. Brice, H.L. Fraser, Scr. Mater. 45 (2011) 1123. [2] G.F. Sun, R. Zhou, J.Z. Lu, J. Mazumder, Acta Mater. 84 (2015) 172. [3] Y.Y. Zhu, J. Li, X.J. Tian, H.M. Wang, D. Liu, Mater. Sci. Eng.: A 607 (2014) 427.
[4] [5] [6] [7] [8] [9] [10] [11] [12] [13]
J.N. Li, H.J. Yu, C.Z. Chen, S.L. Gong, J. Phys. Chem. C 117 (2013) 4568. J.N. Li, K.G. Liu, S.L. Gong, Y.B. Zhang, P. Liu, Physica E 66 (2015) 317. F. Wang, J. Mei, H. Jiang, X. Wu, Mater. Sci. Eng. A 445-446 (2007) 461. J.N. Li, S.L. Gong, Physica E 47 (2013) 193–196. D.T.A. Matthews, V. Ocelik, D. Branagan, J.Th.M. de Hosson, Surf. Coat. Technol. 203 (2009) 1833. P. Liu, Y.B. Zhang, H. Luo, Surf. Eng. 28 (2012) 532. D.D. Gu, G.B. Meng, C. Li, W. Merners, R. Poprawe, Scr. Mater. 67 (2012) 185. F. Weng, C.Z. Chen, H.J. Yu, Mater. Des. 58 (2014) 412. Y.H. Diao, K.M. Zhang, Appl. Surf. Sci. 352 (2015) 163. M. Masanta, S.M. Shariff, A. Roy Choudhury, Mater. Des. 90 (2016) 307.
Contents lists available at ScienceDirect
Physica E journal homepage: www.elsevier.com/locate/physe
Laser fabrication nanocrystalline coatings using simultaneous powders/wire feed Jianing Li a,n, Tongguang Zhai a,b, Yuanbin Zhang a, Feihu Shan c, Peng Liu a, Guocheng Ren a a
School of Materials Science and Engineering, Shandong Jianzhu University, Fengming Road #1000, Jinan 250101, PR China Department of Chemical and Materials Engineering, University of Kentucky, Lexington, KY 40506, USA c Beijing Aeronautical Manufacturing Technology Research Institute, Beijing 100024, PR China b
H I G H L I G H T S
Simultaneously feeding TC17 wire and Stellite 20–Si3N4–TiC–Sb mixed powders formed composites. Sb addition in laser molten pool was favorable to the formations of UNs. UNs were intertwined with amorphous, leading the yarn-shape materials to be produced. Ti entered into molten pool from the wire and TA1, which may react with Si or N.
art ic l e i nf o
a b s t r a c t
Article history: Received 17 January 2016 Received in revised form 12 February 2016 Accepted 16 February 2016 Available online 18 February 2016
Laser melting deposition (LMD) fabrication is used to investigate feasibilty of simultaneously feeding TC17 wire and the Stellite 20–Si3N4–TiC–Sb mixed powders in order to increase the utilization ratio of materials and also quality of LMD composite coatings on the TA1 substrate. SEM images indicated that such LMD coating with metallurgical joint to substrate was formed free of the obvious defects. Lots of the ultrafine nanocrystals (UNs) were produced, which distributed uniformly in some coating matrix location, retarding growth of the ceramics in a certain extent; UNs were intertwined with amorphous, leading the yarn-shape materials to be produced. Compared with substrate, an improvement of wear resistance was achieved for such LMD coating. & 2016 Elsevier B.V. All rights reserved.
Keywords: Metal-matrix composites (MMCs) Surface properties Nanocrystalline materials Lasers
1. Introduction Direct LMD fabrication is a novel manufacturing technique developed about a decade ago which can directly fabricate 3D near net shape and fully dense components from metal powders in one step [1,2]. During such fabrication, the powder is fed at a controlled rate into the focal point of a laser where individual particles are melted as the movement of the laser follows the path defined by a CAD file of a component [3]. Recently, nano-composite coatings have become very popular because of their high toughness and stiffness along with the superior hardness and wear properties; amorphous alloys have attracted increasing attention because of their excellent properties, such as high hardness, corrosion and wear resistance, etc. [4,5]. Laser fabrication is a promising method n
Corresponding author. E-mail address: [email protected] (J.N. Li).
http://dx.doi.org/10.1016/j.physe.2016.02.014 1386-9477/& 2016 Elsevier B.V. All rights reserved.
to prepare the amorphous-nanocrystals reinforced coatings on metals substrate, improving the surface performance of metals substrate. In the last few years, lots of the effects have focused mainly on the powder feed laser deposition, while less work has been carried out on the microstructure performance of the simultaneous mixed powders and wire feeding laser deposited composites. The problem of single powders feed laser deposition is that low capture rate of the powders (10–30%), leads to wastage of the scattered powders (i.e. 90–70% of the feedstock) [6]. Through experimental work, it was confirmed that simultaneous LMD of the Stellite 20–Si3N4–TiC–Sb mixed powders and TC17 wire on titanium alloy can form the wear resistance amorphousnanocrystalline composite coatings. In this study, LMD fabrication is used to investigate the feasibilty of simultaneously feeding wire and mixed powders in order to increase the utilization ratio of materials and the quality of the laser fabricated composite coatings. Laser wire deposition technology will have a great application potential in industry fabrication fields.
J.N. Li et al. / Physica E 81 (2016) 44–48
Fig. 1. Schematic of direct LMD with simultaneous mixed powders and wire feed.
2. Experimental A LMD technique was conducted on a YAG (HL 3006D) laser materials processing system equipped with four-axis computer numerical controlled (CNC) laser materials processing machine under the vacuum environment, coaxial powder feeding device (DPSF-3) were employed to melt surfaces of samples; a CNCcontrolled wire feed system, including a precision wire feed nozzle
45
developed in-house, was used which can deliver wires with a diameter equal to or large than 0.4 mm. Materials used to be substrate: TA1 titanium alloy samples (10 mm 10 mm 32 mm) for wear test, or samples (10 mm 10 mm 10 mm) for microstructure analysis, chemical compositions (wt%) of TA1: 0.3Fe, 0.15Si, 0.1C, 0.05N, 0.015H and bal. Ti. Samples surfaces were ground with emery paper to remove the oxide scale, and rinsed with alcohol before a LMD process. The TC17 wire was used in this experiment, chemical compositions (wt%) of TC17: 4.60Al, 1.72Sn, 1.91Zr, 4.01Mo, 3.81Cr, 0.137O and bal. Ti; the powders mixture of Stellite 20 (Z99.5% purity, 50– 150 μm), Si3N4 ( Z99.5% purity, 50–150 μm), TiC ( Z99.5% purity, 50–150 μm), and Sb (Z99.5% purity, 5–50 μm) were used for a LMD technique. Compositions (wt%) of 80Stellite 20–7Si3N4 10TiC–3Sb were used to deposit on a TA1 alloy by a LMD process, chemical compositions (wt%) of Stellite 20: 2.45C, 32.50Cr, 1.00Si, 17.00W, 3.00Fe, 1.000Mo, 3.00Ni, bal. Co. Laser power¼1.8 kW, scanning velocity¼ 5–11.0 mm/s, powder feed rate¼15 g/min, wire feed rate¼5 mm/s, wire diameter¼ 1 mm and laser beam diameter¼4 mm, and an overlap of 30% between successive tracks was selected. Whole experiment process was in progress in an Ar environment box. During the LMD process, the substrate was irradiated by laser beam while the powders mixture and wire were also sent to the laser molten pool simultaneously, forming the composite coating (see Fig. 1). Microstructural morphologies of such LMD composite coating were analyzed by means of a LEO 1525 scanning electron microscope (SEM) and a Titan 80–300 high resolution transmission
Fig. 2. SEM images of LMD coating: (a) bond zone; (b) middle-coating; (c) UNs; (d) dendrites.
46
J.N. Li et al. / Physica E 81 (2016) 44–48
Fig. 3. Images (SEM/HRTEM) of this LMD coating: (a) eutectics; (b) yarn-shape materials; (c) eutectics in interface; (d) HRTEM image of middle-coating.
electron microscope (HRTEM); wear properties of such coating were tested by a WMM-W1 disc wear tester, the wear volume losses were measured interval every 10 min; the rotational speed of the wear tester was 425 r/min.
3. Results and analysis 3.1. SEM and HRTEM analysis As shown in Fig. 2a, there were the interdendritic lamellar eutectic phases made up mainly of Ni, Co and small amounts of other chemical elements in bottom of the LMD composite coating with a metallurgical combination with a TA1 substrate free of the obvious defects. It was noted that the fine block-shape precipitates were dispersed in the middle-coating (see Fig. 2b). Lots of N were released from Si3N4 during a LMD process, which were able to react with TiC in laser molten pool, forming the Ti(CN) block-shape strengthening phase [7]. It was also observed that lots of UNs were produced, which distributed uniformly in some location of middle-coating matrix (see Fig. 2c). The fact that the Sb addition in laser molten pool was favorable to the formations of UNs in such laser-treated coatings. Such nano-phase were formed via a dissolution/precipitation mechanism by means of the heterogeneous nucleation of nano nuclei and the subsequent grain grow. The effective crystal development of nano nuclei was significantly restricted due to insufficient time of existence time of molten pool for grain growth to occur, hence favorable ultrafine nano structure of the reinforcing phases was retained [8].
In addition, due to an uneven energy distribution of the laser molten pool, TiC in some location absorbed enough energy from the laser beam and grew in the dendrites (see Fig. 2d); moreover, due to addition of the TC17 wire and the dilution effect, lots of Ti entered into the molten pool from the wire and substrate, which may react with Si or N those released from the Si3N4, forming Ti-Si eutectics or TiN, respectively. Investigations [9] indicated that TiN may also grew in the dendrites in some sufficient locations of molten pool; further, as mentioned previously, the Sb addtion promoted lots of UNs to be produced, which may retard growth of the ceramics, such as TiN or TiC, etc. [10]. Thus, those ceramics exhibited fine microstructure. As shown in Fig. 3a, the eutectics were produced in the matrix of middle-coating, even a large quantity of UNs were observed attached to them. Usually, the melting point of alloy is lower than that of pure metal, and the melting point of liquid alloying lowest when the liquid alloying is closed to the eutectics elements, favoring the formation of amorphous phase [8]; it was noted that the yarn-shape materials without the obvious structures were obtained in such coating (see Fig. 3b). It was speculated that UNs were intertwined with amorphous, leading the yarn-shape materials to be produced; in addition, the eutectics were also observed in an interface of such yarn-shape materials (see Fig. 3c), such structure may strongly modify the wear and high temperature properties of the Ti-Al/Ti-Co intermetallics matrix. Fig. 3d indicated that the fine crystalline phases were engulfed by amorphous phases. It was speculate that UNs were intertwined with the amorphous, leading the yarn-shape materials to be produced; further, UNs may have a high interface energy, which became the
J.N. Li et al. / Physica E 81 (2016) 44–48
47
Fig. 4. Wear pattern and images of worn surface of LMD coating/TA1: (a) Wear pattern; (b) worn surface of TA1; (c) worn surface of LMD sample; (d) the etched worn surface of LMD sample.
driving force of the atomic motions, favoring formation of a compact fine structure [11]. 3.2. Wear properties Fig. 4a indicated that when the load was 10 kg, the wear volume losses of TA1 and the LMD coating increased with prolongation of the wear sliding time. The test results indicated that the wear volume loss of the such LMD coating was approximately 1/6 of TA1. Better wear resistance of such coating was mainly ascribed to the actions of the phase constituent, the compact microstructure and the solid solution/nanocrystals-amorphous strengthening. As shown in Fig. 4b and c, under the dry-sliding wear test, worn surface of LMD sample was more smooth than that of substrate, the adhesion patches and deep plowing grooves were existence. The fact that the formation of smooth worn surface of LMD sample was also mainly ascribed to the actions of the fine grain, the solid solution, amorphous-nanocrystalline and hard phases strengthening; for instence, the fine grain strengthening of the Ti(CN) precipitates, the solid solution strengthening of Si and Cr in γ-Co, the Fe base amorphous strengthening, etc. Under the action of the pinning effect of the precipitates, such as TiC and Ti (CN), the counterpart should overcome the hinders of these fine and dense precipitates, preventing formations of the deep plowing grooves during the sliding wear process [12,13]. As shown in Fig. 4d, lots of the fine precipitates were present in the etched worn surface of the LMD sample. The productions of these fine precipitates were beneficial in formation of smooth
surface. The fact that the moderate growth dispersal fine particles or fine precipitates may withstand external normal load better, which showed the excellent properties of the plasticity, wear and toughness, favoring an improvement of wear resistance, forming a smooth worn surface.
4. Conclusions In summary, composites of TC17 containing different volume fractions of Stellite 20–Si3N4–TiC–Sb were manufactured using a LMD technique. TC17 wire and the Stellite 20–Si3N4–TiC–Sb mixed powders were fed into the laser molten pool on TA1 titanium alloy substrate simultaneously. Due to the addition of the TC17 wire and the dilution effect, lots of Ti entered into the molten pool from the wire and TA1 substrate, which may react with Si or N those released from the Si3N4, forming the Ti-Si eutectics or TiN, respectively. Such LMD coating with metallurgical joint to substrate was formed free of the obvious defects. Sb addition in laser molten pool was favorable to the formation of the UNs in the laser-treated coatings; lots of UNs were produced, which distributed uniformly in some location of the coating matrix, retarding growth of the ceramics in a certain extent. UNs were intertwined with amorphous, leading the yarn-shape materials to be produced. When load was 10 kg, the wear volume loss of the such LMD coating was approximately 1/6 of TA1 after 10 min wear test.
48
J.N. Li et al. / Physica E 81 (2016) 44–48
Acknowledgments This project is supported by National Natural Science Foundation of China (Grant no. 51505257).
References [1] K.I. Schwendner, R. Banerjee, P.C. Collins, C.A. Brice, H.L. Fraser, Scr. Mater. 45 (2011) 1123. [2] G.F. Sun, R. Zhou, J.Z. Lu, J. Mazumder, Acta Mater. 84 (2015) 172. [3] Y.Y. Zhu, J. Li, X.J. Tian, H.M. Wang, D. Liu, Mater. Sci. Eng.: A 607 (2014) 427.
[4] [5] [6] [7] [8] [9] [10] [11] [12] [13]
J.N. Li, H.J. Yu, C.Z. Chen, S.L. Gong, J. Phys. Chem. C 117 (2013) 4568. J.N. Li, K.G. Liu, S.L. Gong, Y.B. Zhang, P. Liu, Physica E 66 (2015) 317. F. Wang, J. Mei, H. Jiang, X. Wu, Mater. Sci. Eng. A 445-446 (2007) 461. J.N. Li, S.L. Gong, Physica E 47 (2013) 193–196. D.T.A. Matthews, V. Ocelik, D. Branagan, J.Th.M. de Hosson, Surf. Coat. Technol. 203 (2009) 1833. P. Liu, Y.B. Zhang, H. Luo, Surf. Eng. 28 (2012) 532. D.D. Gu, G.B. Meng, C. Li, W. Merners, R. Poprawe, Scr. Mater. 67 (2012) 185. F. Weng, C.Z. Chen, H.J. Yu, Mater. Des. 58 (2014) 412. Y.H. Diao, K.M. Zhang, Appl. Surf. Sci. 352 (2015) 163. M. Masanta, S.M. Shariff, A. Roy Choudhury, Mater. Des. 90 (2016) 307.