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Ni Mixed Powders
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J. Mater. Sci. Technol., 2013, 29(8), 757e760
Microstructure and Magnetic Properties of FeeNi Alloy Fabricated by Selective Laser Melting Fe/Ni Mixed Powders Baicheng Zhang*, Nour-Eddine Fenineche, Hanlin Liao, Christian Coddet LERMPS, Université de Technologie de Belfort-Montbéliard, Site de Sévenans, Belfort Cedex 90010, France [Manuscript received June 22, 2012, in revised form November 20, 2012, Available online 22 May 2013]
FeeNi alloy, as a widely applied ferromagnetic material, is synthesized using selective laser melting (SLM). The chemical compositions and microstructure of the SLM FeeNi alloy are characterized by X-ray diffraction (XRD), energy dispersive X-ray spectroscopy and scanning electron microscopy. It was found that the samples exhibited fine grains with homogenous distribution when a low laser scanning velocity was used. Moreover, the magnetic properties of the samples with different laser parameters are also measured. It shows that the SLM Fee30%Ni alloy possesses a low coercivity and high saturation magnetization. It also can be obtained that SLM is an alternative faster method to prepare soft magnetic material with complex shapes. Moreover, the magnetic properties can be influenced by the laser parameters. KEY WORDS: Selective laser melting (SLM); FeeNi alloy; Soft magnetic materials; Magnetic property
1. Introduction FeeNi alloy, as a soft magnetic material with high permeability and low coercivity in weak magnetic field, is widely applied in industry. However, the conventional processing method of FeeNi alloy fabrication is hard to elaborate parts with complex shape and to obtain perfect magnetic properties due to work hardening of Ni element[1e3]. Recently, processing of composite materials by laser fabrication such as selective laser melting/selective laser sintering (SLM/SLS) has attracted interest due to the process potential in free-form fabrication of intricate articles with a reduced production cycle. Especially, SLM is a commercial technique for elaborating complex-shape parts directly from CAD data with metal powders[4,5]. Many kinds of functional materials, such as wear resistant material, ultra-light alloy and hydrogen storage material have been successfully synthesized. For instance, SLM of TiNeTi5Si3[6], TieAleC[7], Mge7Mg alloy[8], Ale7Sie0.3 Mg alloy[9] have been reported. However, so far, laser synthesized FeeNi alloy, as ferromagnetic material has been rarely reported. In this work, SLM of the Fee 30%Ni mixed powders is performed to prepare Fee30%Ni alloy. The microstructural features of the Fee30%Ni alloy under different laser processing parameters were characterized. Corresponding author. Ph.D.; Tel.: þ33 384583243; E-mail address: [email protected] (B. Zhang). 1005-0302/$ e see front matter Copyright Ó 2013, The editorial office of Journal of Materials Science & Technology. Published by Elsevier Limited. All rights reserved. http://dx.doi.org/10.1016/j.jmst.2013.05.001 *
Moreover, the reasonable synthesis mechanisms behind microstructural developments were explained. 2. Experimental The characteristics of the materials used in the present experiment are summarized in Table 1. Nickel powder with an atomic fraction of 30% was added into the iron powder. Then, the mixed powders were blended in a Tumbling mixer for 45 min. The powder mixture was processed layer by layer to form cubic specimens with dimensions of 5 mm 5 mm 5 mm using an MCP Realize Ⅱmachine (MCP 250 HEK Tooling GmbH, Germany) which mainly consisted of a Nd:YAG laser source with wavelength of 1064 nm. By optimizing laser parameters, the investigated laser melting power was fixed at 110 W. In order to reveal the evolution of physical properties, the scanning velocity n was picked by 0.1 m/s, 0.4 m/s, and 1.6 m/s. The diameter (d) of the laser beam was 0.05 mm. The elaboration process was performed under argon atmosphere, and the powder bed temperature was kept constant at 80 C during laser processing. Fig. 1 shows the working chamber of laser melting and the obtained samples after processing. After removing the melted specimens from the building plate, the porosity rate of the samples was measured by Archimedes method[10]. Then the samples were cut and ground for metallographic examination according to standard procedures. A 6% nitric solution was taken as an etching agent with an etching time of 15 s. The microstructure was characterized by scanning electron microscopy (SEM, JEOL, JSM-5800LV, Japan), coupled with an energy dispersive spectrometer (EDS). The
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B. Zhang et al.: J. Mater. Sci. Technol., 2013, 29(8), 757e760
Table 1 Characteristics of powders Materials
Particle size (mm)
Mean value (mm)
Particle shape
Supplier
Fe Ni
<60 <58
35 30
Spherical Spherical
LERMPS Medicoat AG, Switzerland
magnetic measurements were performed using a hysteresimeter Bull M 2000/2010, which allowed to measure coercivity and saturation magnetization. 3. Results and Discussion
Fig. 2 X-ray diffraction patterns of the laser-melted samples and starting powder with parameters: laser melting power 110 W and scanning velocity 0.1 m/se1.6 m/s.
3.1. Phase Fig. 2 shows the XRD patterns of the Fee30%Ni alloy with scanning velocities of 0.1 m/s, 0.4 m/s, and 1.6 m/s; laser powder of 110 W. The strong diffraction peaks corresponding to Fe7Ni3 and Fe3Ni2 are clearly observed in the samples, while no apparent diffraction peaks for the initial Fe and Ni phases are detected. In addition, from the intensity of the diffraction peaks, it can be observed that the content of these intermetallic compounds is different in these samples: the low laser scanning velocity leads to a weak intensity of diffraction peaks for Fe3Ni2. Thus, it can be preliminarily considered that the synthesis reaction of FeeNi system by SLM can be accomplished by two steps: 3Fe þ 2Ni ¼ Fe3 Ni2
(1)
3Fe3 Ni2 þ 6Fe ¼ 2Fe7 Ni3
(2)
In the initial phase of the SLM process, the reaction (1) can take place at relatively low reaction temperature as the molten pool was formed in which the temperature was just higher than melting point due to the negative Gibbs free energies of this reaction[11]. Moreover, the temperature of molten pool can be increased with the laser energy input continuously. Thus, the remained Fe element can be involved into reaction (2) because the Gibbs free energy of this reaction is much less than reaction
(1). Therefore, the reaction (2) depends on whether there is a strong driving force and a long reaction time. By comparing XRD results of the three samples, the Fe7Ni3 phase can be found in all the samples. Only the phase in the sample with scanning velocity of 0.1 m/s corresponded to Fe7Ni3. Thus, it is reasonable to conclude that the low laser scanning velocity is suited to yield promising Fee30%Ni alloy due to the relatively high operation temperature and long reaction time. 3.2. Microstructures and compositions Fig. 3 shows the microstructural characteristics of the samples on the etched section. Fine dendritic grains can be found in the sample with scanning velocity of 0.1 m/s, and the coarse grains are distributed within fine grain matrix with scanning velocities of 0.4 m/s and 1.6 m/s. In order to further determine the elemental distributions, EDS point measurements were performed. On the one hand, EDS results reveal that the Fe and Ni elements in the sample with scanning velocity of 0.1 m/s is nearly equal to atomic proportion of 7:3 within these grains. The XRD results show that the sample with low scanning velocity is composed of pure Fe7Ni3. On the other hand, the EDS results show that the Fe and Ni elements within the matrix (Point 1, Fig. 3(b) and (c)) with scanning velocities of 0.4 m/s and 1.6 m/s are also about 7:3. However, the disorder and gross grain within the matrix is composed of the Fe and Ni elements with atomic
Fig. 1 A view of laser melting for Fee30%Ni alloy (a) and samples after melting (b).
B. Zhang et al.: J. Mater. Sci. Technol., 2013, 29(8), 757e760
759
Fig. 3 SEM micrographs showing the microstructure of laser melting samples with scanning velocity (a) 0.1 m/s, (b) 0.4 m/s, (c) 1.6 m/s and laser melting power 110 W.
ratio of about 3:2 (Point 2, Fig. 3(b) and (c)). Thus, it is reasonable to consider that the Fe3Ni2 grains are completely extracted via deep etching and dissolution of the metallic matrix Fe7Ni3, which is presented in XRD results. Furthermore, the formation of fine grains originates from high undercooling during the solidification process which can be attributed to the intense heat absorption and elimination of heat between molten pool and substrate. Moreover, the Marangoni flow[12] formed in the molten pool can lead to a high nucleation rate in solidification. Once the temperature of molten pool decreased to melting point, the nucleation growth process accelerates instantly and forms fine grains finally as shown in Fig. 3(a). Therefore, the intensity of Marangoni flow from upside to downside decreases in the molten pool when a high scanning velocity is used, which leads to a relatively low nucleation rate. Then, the relatively gross grains can be found in Fig. 3(b) and (c). Combined with the XRD, SEM, and EDS results, it can be confirmed that the Fee30%Ni composites are successfully prepared by SLM of FeeNi mixed powders.
coercivity of soft magnetic materials strongly depends on the microstructural characteristics of the material, parameters such as grain size and its distribution and the amount of defects (intraand inter-granular holes, inclusions, vacancies, dislocations, etc). Therefore, the movement of the magnetic domain can be obstructed by defects as mentioned above under the external magnetic field effect. The internal stress of the samples using low scanning velocity is higher than that of using high scanning velocity. Thus, the internal stress becomes the principal obstruction in magnetic field. It can be obtained that the higher the scanning velocity, the higher the coercivity. Furthermore, the gradual increase of porosity rate and the heterogenous distribution of FeeNi intermetallic compound result in a pinning effect[14] which intensively restrain the movement of magnetic domain during the magnetic variation. In addition, referring to the foregoing theory, the sample with scanning velocity of 0.4 m/ s possesses a low anisotropy due to higher Fe2Ni3 content and less defects of structure. Thus, the valley point of coercivity curve happened in 0.4 m/s can be easily explained.
3.3. Research on magnetic performance Fig. 4 shows the evolution of saturation magnetization and coercivity via different laser scanning velocity. It can be found that the saturation magnetization of FeeNi alloy using scanning velocity of 0.1 m/s is nearly similar to that of conventional casting Fee30%Ni alloy[13]. Furthermore, the effect of anisotropy on the magnetic properties cannot be ignored. According to the XRD results, high laser scanning velocity can lead to a Fe3Ni2 <111> phase which possesses low anisotropy constant K. Thus, a high saturation magnetization can be obtained when using the middle scanning velocity of 0.4 m/s. Contrarily, The combination of Fe7Ni3 and Fe3Ni2 with a relatively high porosity rate can lead to a relatively low saturation magnetization when scanning velocity of 1.6 m/s is used due to a relatively high anisotropy constant K. It can be reasonably concluded that the
Fig. 4 Saturation magnetization and coercivity curves for FeeNi alloy with different laser parameters.
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B. Zhang et al.: J. Mater. Sci. Technol., 2013, 29(8), 757e760
According to Fig. 4, the maximum MS and minimal HC values can be obtained as MS ¼ 550 Am2/kg and HC ¼ 75 A/m, respectively. Compared with the conventional casting Fee30% Ni alloy[13] (MS ¼ 400 Am2/kg, HC ¼ 480 A/m), the SLM Fee 30%Ni with scanning velocity of 0.4 m/s and laser power 110 W possesses a better magnetic property. 4. Conclusion With the introduction of SLM in FeeNi alloy process, the FeeNi soft magnetic materials were realized. The magnetic properties of SLM Fee30%Ni alloy showed a strong microstructure dependence, with the favorable values of MS ¼ 550 Am2/kg, HC ¼ 75 A/m, corresponding to a microstructures with a fine grain size and low porosity rate. Acknowledgment Authors thank Mr. Eric AUBRY (Nipson Belfort France), for his assistance concerning magnetic measurements.
REFERENCES [1] J.A. Verduzco, I. Betancourt, N. Ortiz, L.R. Olmos, J. Garcia, Mater. Lett. 60 (2006) 2033e2037. [2] J. Namkung, M.C. Kim, C.G. Park, Mater. Sci. Eng. A 375e377 (2004) 1116e1120. [3] R. Hamzaoui, O. Elkedim, N. Fenineche, E. Gaffet, J. Craven, Mater. Sci. Eng. A 360 (2003) 305e399. [4] D. Gu, Y. Shen, Mater. Lett. 60 (2006) 3664e3668. [5] H. Niu, I. Chang, Scripta Mater. 41 (1999) 25e30. [6] D. Gu, Y. Shen, Z. Lu, Mater. Lett. 63 (2009) 1577e1579. [7] D. Gu, Y. Shen, G. Meng, Mater. Lett. 63 (2009) 2536e2538. [8] B. Zhang, H. Liao, C. Coddet, Mater. Des. 34 (2012) 753e758. [9] A. Simchi, D. Godlinski, Scripta Mater. 59 (2008) 199e202. [10] ISO Standards 5017. [11] R.H. De Tendler, C. Rodriguez, J. Mater. Sci. 31 (1996) 6395e6402. [12] L. Pawlowski, J. Ther. Spr. Tech. 8 (1999) 279e295. [13] G.A. Alers, J.R. Neighbours, H. Sato, J. Phy. Chem. Solids 13 (1960) 40e55. [14] B. Lu, M.Q. Huang, Q. Chen, B.M. Ma, D.E. Laughlin, J. Magn. Magn. Mater. 195 (1999) 611e619.
J. Mater. Sci. Technol., 2013, 29(8), 757e760
Microstructure and Magnetic Properties of FeeNi Alloy Fabricated by Selective Laser Melting Fe/Ni Mixed Powders Baicheng Zhang*, Nour-Eddine Fenineche, Hanlin Liao, Christian Coddet LERMPS, Université de Technologie de Belfort-Montbéliard, Site de Sévenans, Belfort Cedex 90010, France [Manuscript received June 22, 2012, in revised form November 20, 2012, Available online 22 May 2013]
FeeNi alloy, as a widely applied ferromagnetic material, is synthesized using selective laser melting (SLM). The chemical compositions and microstructure of the SLM FeeNi alloy are characterized by X-ray diffraction (XRD), energy dispersive X-ray spectroscopy and scanning electron microscopy. It was found that the samples exhibited fine grains with homogenous distribution when a low laser scanning velocity was used. Moreover, the magnetic properties of the samples with different laser parameters are also measured. It shows that the SLM Fee30%Ni alloy possesses a low coercivity and high saturation magnetization. It also can be obtained that SLM is an alternative faster method to prepare soft magnetic material with complex shapes. Moreover, the magnetic properties can be influenced by the laser parameters. KEY WORDS: Selective laser melting (SLM); FeeNi alloy; Soft magnetic materials; Magnetic property
1. Introduction FeeNi alloy, as a soft magnetic material with high permeability and low coercivity in weak magnetic field, is widely applied in industry. However, the conventional processing method of FeeNi alloy fabrication is hard to elaborate parts with complex shape and to obtain perfect magnetic properties due to work hardening of Ni element[1e3]. Recently, processing of composite materials by laser fabrication such as selective laser melting/selective laser sintering (SLM/SLS) has attracted interest due to the process potential in free-form fabrication of intricate articles with a reduced production cycle. Especially, SLM is a commercial technique for elaborating complex-shape parts directly from CAD data with metal powders[4,5]. Many kinds of functional materials, such as wear resistant material, ultra-light alloy and hydrogen storage material have been successfully synthesized. For instance, SLM of TiNeTi5Si3[6], TieAleC[7], Mge7Mg alloy[8], Ale7Sie0.3 Mg alloy[9] have been reported. However, so far, laser synthesized FeeNi alloy, as ferromagnetic material has been rarely reported. In this work, SLM of the Fee 30%Ni mixed powders is performed to prepare Fee30%Ni alloy. The microstructural features of the Fee30%Ni alloy under different laser processing parameters were characterized. Corresponding author. Ph.D.; Tel.: þ33 384583243; E-mail address: [email protected] (B. Zhang). 1005-0302/$ e see front matter Copyright Ó 2013, The editorial office of Journal of Materials Science & Technology. Published by Elsevier Limited. All rights reserved. http://dx.doi.org/10.1016/j.jmst.2013.05.001 *
Moreover, the reasonable synthesis mechanisms behind microstructural developments were explained. 2. Experimental The characteristics of the materials used in the present experiment are summarized in Table 1. Nickel powder with an atomic fraction of 30% was added into the iron powder. Then, the mixed powders were blended in a Tumbling mixer for 45 min. The powder mixture was processed layer by layer to form cubic specimens with dimensions of 5 mm 5 mm 5 mm using an MCP Realize Ⅱmachine (MCP 250 HEK Tooling GmbH, Germany) which mainly consisted of a Nd:YAG laser source with wavelength of 1064 nm. By optimizing laser parameters, the investigated laser melting power was fixed at 110 W. In order to reveal the evolution of physical properties, the scanning velocity n was picked by 0.1 m/s, 0.4 m/s, and 1.6 m/s. The diameter (d) of the laser beam was 0.05 mm. The elaboration process was performed under argon atmosphere, and the powder bed temperature was kept constant at 80 C during laser processing. Fig. 1 shows the working chamber of laser melting and the obtained samples after processing. After removing the melted specimens from the building plate, the porosity rate of the samples was measured by Archimedes method[10]. Then the samples were cut and ground for metallographic examination according to standard procedures. A 6% nitric solution was taken as an etching agent with an etching time of 15 s. The microstructure was characterized by scanning electron microscopy (SEM, JEOL, JSM-5800LV, Japan), coupled with an energy dispersive spectrometer (EDS). The
758
B. Zhang et al.: J. Mater. Sci. Technol., 2013, 29(8), 757e760
Table 1 Characteristics of powders Materials
Particle size (mm)
Mean value (mm)
Particle shape
Supplier
Fe Ni
<60 <58
35 30
Spherical Spherical
LERMPS Medicoat AG, Switzerland
magnetic measurements were performed using a hysteresimeter Bull M 2000/2010, which allowed to measure coercivity and saturation magnetization. 3. Results and Discussion
Fig. 2 X-ray diffraction patterns of the laser-melted samples and starting powder with parameters: laser melting power 110 W and scanning velocity 0.1 m/se1.6 m/s.
3.1. Phase Fig. 2 shows the XRD patterns of the Fee30%Ni alloy with scanning velocities of 0.1 m/s, 0.4 m/s, and 1.6 m/s; laser powder of 110 W. The strong diffraction peaks corresponding to Fe7Ni3 and Fe3Ni2 are clearly observed in the samples, while no apparent diffraction peaks for the initial Fe and Ni phases are detected. In addition, from the intensity of the diffraction peaks, it can be observed that the content of these intermetallic compounds is different in these samples: the low laser scanning velocity leads to a weak intensity of diffraction peaks for Fe3Ni2. Thus, it can be preliminarily considered that the synthesis reaction of FeeNi system by SLM can be accomplished by two steps: 3Fe þ 2Ni ¼ Fe3 Ni2
(1)
3Fe3 Ni2 þ 6Fe ¼ 2Fe7 Ni3
(2)
In the initial phase of the SLM process, the reaction (1) can take place at relatively low reaction temperature as the molten pool was formed in which the temperature was just higher than melting point due to the negative Gibbs free energies of this reaction[11]. Moreover, the temperature of molten pool can be increased with the laser energy input continuously. Thus, the remained Fe element can be involved into reaction (2) because the Gibbs free energy of this reaction is much less than reaction
(1). Therefore, the reaction (2) depends on whether there is a strong driving force and a long reaction time. By comparing XRD results of the three samples, the Fe7Ni3 phase can be found in all the samples. Only the phase in the sample with scanning velocity of 0.1 m/s corresponded to Fe7Ni3. Thus, it is reasonable to conclude that the low laser scanning velocity is suited to yield promising Fee30%Ni alloy due to the relatively high operation temperature and long reaction time. 3.2. Microstructures and compositions Fig. 3 shows the microstructural characteristics of the samples on the etched section. Fine dendritic grains can be found in the sample with scanning velocity of 0.1 m/s, and the coarse grains are distributed within fine grain matrix with scanning velocities of 0.4 m/s and 1.6 m/s. In order to further determine the elemental distributions, EDS point measurements were performed. On the one hand, EDS results reveal that the Fe and Ni elements in the sample with scanning velocity of 0.1 m/s is nearly equal to atomic proportion of 7:3 within these grains. The XRD results show that the sample with low scanning velocity is composed of pure Fe7Ni3. On the other hand, the EDS results show that the Fe and Ni elements within the matrix (Point 1, Fig. 3(b) and (c)) with scanning velocities of 0.4 m/s and 1.6 m/s are also about 7:3. However, the disorder and gross grain within the matrix is composed of the Fe and Ni elements with atomic
Fig. 1 A view of laser melting for Fee30%Ni alloy (a) and samples after melting (b).
B. Zhang et al.: J. Mater. Sci. Technol., 2013, 29(8), 757e760
759
Fig. 3 SEM micrographs showing the microstructure of laser melting samples with scanning velocity (a) 0.1 m/s, (b) 0.4 m/s, (c) 1.6 m/s and laser melting power 110 W.
ratio of about 3:2 (Point 2, Fig. 3(b) and (c)). Thus, it is reasonable to consider that the Fe3Ni2 grains are completely extracted via deep etching and dissolution of the metallic matrix Fe7Ni3, which is presented in XRD results. Furthermore, the formation of fine grains originates from high undercooling during the solidification process which can be attributed to the intense heat absorption and elimination of heat between molten pool and substrate. Moreover, the Marangoni flow[12] formed in the molten pool can lead to a high nucleation rate in solidification. Once the temperature of molten pool decreased to melting point, the nucleation growth process accelerates instantly and forms fine grains finally as shown in Fig. 3(a). Therefore, the intensity of Marangoni flow from upside to downside decreases in the molten pool when a high scanning velocity is used, which leads to a relatively low nucleation rate. Then, the relatively gross grains can be found in Fig. 3(b) and (c). Combined with the XRD, SEM, and EDS results, it can be confirmed that the Fee30%Ni composites are successfully prepared by SLM of FeeNi mixed powders.
coercivity of soft magnetic materials strongly depends on the microstructural characteristics of the material, parameters such as grain size and its distribution and the amount of defects (intraand inter-granular holes, inclusions, vacancies, dislocations, etc). Therefore, the movement of the magnetic domain can be obstructed by defects as mentioned above under the external magnetic field effect. The internal stress of the samples using low scanning velocity is higher than that of using high scanning velocity. Thus, the internal stress becomes the principal obstruction in magnetic field. It can be obtained that the higher the scanning velocity, the higher the coercivity. Furthermore, the gradual increase of porosity rate and the heterogenous distribution of FeeNi intermetallic compound result in a pinning effect[14] which intensively restrain the movement of magnetic domain during the magnetic variation. In addition, referring to the foregoing theory, the sample with scanning velocity of 0.4 m/ s possesses a low anisotropy due to higher Fe2Ni3 content and less defects of structure. Thus, the valley point of coercivity curve happened in 0.4 m/s can be easily explained.
3.3. Research on magnetic performance Fig. 4 shows the evolution of saturation magnetization and coercivity via different laser scanning velocity. It can be found that the saturation magnetization of FeeNi alloy using scanning velocity of 0.1 m/s is nearly similar to that of conventional casting Fee30%Ni alloy[13]. Furthermore, the effect of anisotropy on the magnetic properties cannot be ignored. According to the XRD results, high laser scanning velocity can lead to a Fe3Ni2 <111> phase which possesses low anisotropy constant K. Thus, a high saturation magnetization can be obtained when using the middle scanning velocity of 0.4 m/s. Contrarily, The combination of Fe7Ni3 and Fe3Ni2 with a relatively high porosity rate can lead to a relatively low saturation magnetization when scanning velocity of 1.6 m/s is used due to a relatively high anisotropy constant K. It can be reasonably concluded that the
Fig. 4 Saturation magnetization and coercivity curves for FeeNi alloy with different laser parameters.
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B. Zhang et al.: J. Mater. Sci. Technol., 2013, 29(8), 757e760
According to Fig. 4, the maximum MS and minimal HC values can be obtained as MS ¼ 550 Am2/kg and HC ¼ 75 A/m, respectively. Compared with the conventional casting Fee30% Ni alloy[13] (MS ¼ 400 Am2/kg, HC ¼ 480 A/m), the SLM Fee 30%Ni with scanning velocity of 0.4 m/s and laser power 110 W possesses a better magnetic property. 4. Conclusion With the introduction of SLM in FeeNi alloy process, the FeeNi soft magnetic materials were realized. The magnetic properties of SLM Fee30%Ni alloy showed a strong microstructure dependence, with the favorable values of MS ¼ 550 Am2/kg, HC ¼ 75 A/m, corresponding to a microstructures with a fine grain size and low porosity rate. Acknowledgment Authors thank Mr. Eric AUBRY (Nipson Belfort France), for his assistance concerning magnetic measurements.
REFERENCES [1] J.A. Verduzco, I. Betancourt, N. Ortiz, L.R. Olmos, J. Garcia, Mater. Lett. 60 (2006) 2033e2037. [2] J. Namkung, M.C. Kim, C.G. Park, Mater. Sci. Eng. A 375e377 (2004) 1116e1120. [3] R. Hamzaoui, O. Elkedim, N. Fenineche, E. Gaffet, J. Craven, Mater. Sci. Eng. A 360 (2003) 305e399. [4] D. Gu, Y. Shen, Mater. Lett. 60 (2006) 3664e3668. [5] H. Niu, I. Chang, Scripta Mater. 41 (1999) 25e30. [6] D. Gu, Y. Shen, Z. Lu, Mater. Lett. 63 (2009) 1577e1579. [7] D. Gu, Y. Shen, G. Meng, Mater. Lett. 63 (2009) 2536e2538. [8] B. Zhang, H. Liao, C. Coddet, Mater. Des. 34 (2012) 753e758. [9] A. Simchi, D. Godlinski, Scripta Mater. 59 (2008) 199e202. [10] ISO Standards 5017. [11] R.H. De Tendler, C. Rodriguez, J. Mater. Sci. 31 (1996) 6395e6402. [12] L. Pawlowski, J. Ther. Spr. Tech. 8 (1999) 279e295. [13] G.A. Alers, J.R. Neighbours, H. Sato, J. Phy. Chem. Solids 13 (1960) 40e55. [14] B. Lu, M.Q. Huang, Q. Chen, B.M. Ma, D.E. Laughlin, J. Magn. Magn. Mater. 195 (1999) 611e619.