成功大學博碩士論文系統

簡易檢索 / 詳目顯示

回結果列表

研究生：	蕭永豪 Siao, Yong-Hao
論文名稱：	選擇性雷射熔化製程參數之不鏽鋼316L熔池模擬與實驗熱分析 Thermal analysis of process parameters on molten pool by simulation and experiment during selective laser melting of SS316L
指導教授：	温昌達 Wen, Chang-Da
學位類別：	博士 Doctor
系所名稱：	工學院 - 機械工程學系 Department of Mechanical Engineering
論文出版年：	2021
畢業學年度：	109
語文別：	英文
論文頁數：	186
中文關鍵詞：	選擇性雷射熔化、粉末床熔化、馬蘭戈尼效應、異向性熱傳導、高斯熱通量、熔池
外文關鍵詞：	selective laser melting, powder bed fusion, Marangoni effect, anisotropic heat conduction, Gaussian heat flux, molten pool
相關次數：	點閱：123 下載：0
分享至:	分享至facebook 分享至twitter

查詢本校圖書館目錄查詢臺灣博碩士論文知識加值系統勘誤回報

本研究建立三維數值模型模擬選擇性雷射熔化過程，將熱源模擬為高斯分佈的表面熱通量，316L不銹鋼金屬粉末床的粉末表面經過高能雷射處理，研究熔池發展過程的熱傳現象，其中316L不銹鋼的熱物理性為溫度的函數。
首先，本研究基於尺寸、溫度分佈和馬蘭戈尼數，討論熱蒸發、馬蘭戈尼效應、光斑半徑和表面張力梯度對熔池的影響，雷射加工過程中，由馬蘭戈尼效應引起的流體流動，導致熔池形成深窄的形狀，由實驗顯微照片觀察的熔池形狀和尺寸，其結果接近於表面張力梯度為0.45×10-3 N / m K模擬預測的熔池；實驗與模擬使用相同的雷射參數，通過積層製造技術的粉末床熔化設備，進行實驗驗證數值結果並討論熔池的深度、寬度和幾何形狀，隨著光斑半徑的增加，熔池深度和寬度的尺寸也會擴大，較大的表面張力梯度會導致熔池有高馬蘭戈尼數和深長寬比，在實驗和模擬中隨著能量密度的提高，其熔池的深度和寬度會增加。
最後，本研究將馬蘭戈尼流動模型簡化成異向性熱傳導模型，利用兩個數值模型模擬熔池發展，結果表明隨能量密度的提高，異向性熱傳導的增強係數會增加，使用異向性熱傳導模型預測的熔池深度、寬度和形狀與實驗量測值會非常接近，使用異向性熱傳導模型探討粉末層厚度、初始溫度和雷射參數的變化，對熔池的深度、寬度、深寬比和溫度梯度的影響，在固定雷射功率下，使用較高能量密度的雷射參數會導致熔池有更大的深寬比，預先加熱整個粉末床至較高的初始溫度，造成熔池深度方向的溫度梯度有明顯降低的趨勢，從結果中歸納熔池深度和能量密度之間的關係，能夠根據預計的熔池深度適當推導製程參數，此策略可以提高選擇性雷射熔化過程的效率。

A three-dimensional numerical model is established to investigate the heat transfer in the molten pool. A metal powder bed of 316L stainless steel is treated with a high-energy laser on the powder surface, creating a molten pool. The heat flux source simulates as the Gaussian distribution in the model of the selective laser melting process. The thermophysical properties of 316L stainless steel are reliant on the temperature.
Firstly, the influence of the thermal evaporation, Marangoni effect, laser beam radius, and surface tension gradient on the molten pool are discussed based on the dimensions, temperature distribution, and Marangoni number. The fluid flow caused by the Marangoni effect results in the molten pool forming into a deep and narrow shape. The shape and dimension of the molten pool obtained from the experimental micrograph are close to the numerical data adopting a surface tension gradient of 0.45×10-3 N/m K. The depth, width, and geometry of the molten pool are discussed by changed laser conditions. Besides, experiments conducted by a powder bed fusion machine of additive manufacturing technology are performed using those same laser parameters to validate the numerical results. The dimensions, including the depth and width of the molten pool, are expanded as laser beam radius increases. The large surface tension gradient leads to a high Marangoni number and a high aspect ratio for the molten pool. The depth and width of the molten pool in the experiments and simulations tend to rise with the energy density.
Finally, the development of the molten pool is simulated using two numerical models; this is conducted using the Marangoni flow model and the anisotropic heat conduction model. The results present that the enhanced coefficient of the anisotropic heat conduction rises along with the energy density. The depth, width, and shape of the molten pool predicted using the anisotropic heat conduction model are very close to the experimental measurements. This study explores the variations in the powder layer thickness, the initial temperature, and the laser condition. The energy density is employed in this study for the laser settings to discuss the depth, width, aspect ratio, and temperature gradient of the molten pool. The laser settings using higher energy density at a given laser power lead to a larger aspect ratio of the molten pool. The higher initial temperature of the whole powder bed results in a significantly reduced tendency of the temperature gradient. A relationship between the molten pool depth and the energy density is found in the results, which leads to an appropriate estimation of the process parameters necessary to calculate the desired depth and advance the efficiency of the selective laser melting process.

摘要 I
ABSTRACT III
ACKNOWLEDGMENT V
CONTENTS VII
LIST OF TABLES XII
LIST OF FIGURES XIII
NOMENCLATURE XIX
CHAPTER 1	INTRODUCTION 1
1-1	Background 1
1-2	Literature Review 7
1-2-1	Thermal Behavior in Molten Pool 8
1-2-2	Effect of Process Parameter on Molten Pool 10
1-2-3	Product Quality Fabricated by SLM Process 12
1-2-4	Numerical Study of Anisotropic Heat Conduction 14
1-3	Specific Objective 17
1-4	Thesis Architecture 20
CHAPTER 2	FUNDAMENTAL THEORY 22
2-1	Laser Technology 22
2-1-1	Laser Principles 22
2-1-2	Laser Type: Nd-YAG 24
2-1-3	Gaussian Distribution 25
2-2	Thermal Behaviors of Molten Pool 35
2-2-1	Phase Change 35
2-2-2	Heat Source of Laser 39
2-2-3	Thermal Conduction 40
2-2-4	Thermal Convection 41
2-2-5	Thermal Radiation 41
2-2-6	Thermal Evaporation 42
2-2-7	Surface Shear Stress 42
CHAPTER 3	NUMERICAL METHOD 45
3-1	Properties of Material 45
3-1-1	316L Stainless Steel 45
3-1-2	Laser Absorptivity of Powders 46
3-1-3	Packing Density of Powders 48
3-1-4	Effective Thermophysical Properties of Powders 49
3-2	Mathematical model 64
3-2-1	Physical model 64
3-2-2	Basic Assumption 64
3-2-3	Boundary Conditions 66
3-2-4	Marangoni Flow 70
3-2-5	Anisotropic Heat Conduction 72
3-3	Computational Fluid Dynamics Software 79
3-4	Numerical Solving Procedure 82
3-5	Model Validation 84
CHAPTER 4	EXPERIMENTAL APPROACH 88
4-1	Additive Manufacturing Equipment 88
4-2	Metal Powder and Substrate 89
4-3	Optical Microscope Equipment 89
4-4	Experimental Procedure 90
CHAPTER 5	RESULTS AND DISCUSSION 97
5-1	Thermal Behavior in Marangoni Flow Model 97
5-1-1	Thermal evaporation Effect 98
5-1-2	Marangoni Effect 99
5-1-3	Beam Size 100
5-1-4	Surface Tension Gradient 102
5-2	Laser Conditions Effect in Marangoni Flow Model 113
5-2-1	Molten Pool Obtained from Experiments 114
5-2-2	Shape of Molten Pool Validates against Marangoni Flow Model 116
5-2-3	Dimensions of Molten Pool Validate against Marangoni Flow Model 118
5-3	Laser Conditions Effect in Anisotropic Heat conduction Model 132
5-3-1	Shape of Molten Pool Validates against Anisotropic Heat Conduction Model 133
5-3-2	Enhanced Coefficients of Anisotropic Heat Conduction Model 134
5-3-3	Transient Variations in Depth of Melted Region along Y-axis 135
5-3-4	Dimensions of Molten Pool Validate against Anisotropic Heat Conduction Model 136
5-4	Process Parameters Effect in Anisotropic Heat Conduction Model 150
5-4-1	Powder Layer Thicknesses 150
5-4-2	Initial Temperature 152
CHAPTER 6	CONCLUSIONS AND FUTURE WORK 159
6-1	Conclusions 159
6-2	Future Work 162
BIBLIOGRAPHY 164
APPENDIX 175
Appendix-A	Mathematical Formula of SS316 Material 175
Appendix-B	Micrographs of Molten Pools 177
Appendix-C	Powder Bed Fusion Equipment of Selective Laser Melting 185
Appendix-D	Optical Microscope 186
                                    

[1] W.E. Frazier, Metal Additive Manufacturing: A Review, Journal of Materials Engineering and Performance, 23(6) (2014) 1917-1928.
[2] L.-E. Loh, C.-K. Chua, W.-Y. Yeong, J. Song, M. Mapar, S.-L. Sing, Z.-H. Liu, D.-Q. Zhang, Numerical investigation and an effective modelling on the Selective Laser Melting (SLM) process with aluminium alloy 6061, International Journal of Heat and Mass Transfer, 80 (2015) 288-300.
[3] I. Yadroitsev, Selective laser melting: Direct manufacturing of 3D-objects by selective laser melting of metal powders, Lambert Academic Publishing, 2009.
[4] M. Mani, B. Lane, A. Donmez, S. Feng, S. Moylan, R. Fesperman, Measurement Science Needs for Real-time Control of Additive Manufacturing Powder Bed Fusion Processes, National Institute of Standards and Technology, NIST Interagency/Internal Report, NISTIR-8036, 2015.
[5] B. AlMangour, D. Grzesiak, J. Cheng, Y. Ertas, Thermal behavior of the molten pool, microstructural evolution, and tribological performance during selective laser melting of TiC/316L stainless steel nanocomposites: Experimental and simulation methods, Journal of Materials Processing Technology, 257 (2018) 288-301.
[6] L. Han, F.W. Liou, S. Musti, Thermal Behavior and Geometry Model of Melt Pool in Laser Material Process, Journal of Heat Transfer, 127 (2005) 1005-1014.
[7] D. Dai, D. Gu, Q. Ge, Y. Li, X. Shi, Y. Sun, S. Li, Mesoscopic study of thermal behavior, fluid dynamics and surface morphology during selective laser melting of Ti-based composites, Computational Materials Science, 177 (2020) 109598.
[8] P. Bajaj, J. Wright, I. Todd, E.A. Jägle, Predictive process parameter selection for Selective Laser Melting Manufacturing: Applications to high thermal conductivity alloys, Additive Manufacturing, 27 (2019) 246-258.
[9] Y. Du, X. You, F. Qiao, L. Guo, Z. Liu, A model for predicting the temperature field during selective laser melting, Results in Physics, 12 (2019) 52-60.
[10] A. Foroozmehr, M. Badrossamay, E. Foroozmehr, S.i. Golabi, Finite Element Simulation of Selective Laser Melting process considering Optical Penetration Depth of laser in powder bed, Materials & Design, 89 (2016) 255-263.
[11] P.D. Lee, E.D. Hondros, M. McLean, K.C. Mills, P.N. Quested, M. McLean, Modelling of Marangoni effects in electron beam melting, Philosophical Transactions of the Royal Society of London. Series A: Mathematical, Physical and Engineering Sciences, 356(1739) (1998) 1027-1043.
[12] G. Tsotridis, H. Rother, E.D. Hondros, Marangoni flow and the shapes of laser-melted pools, The Science of Nature, 76 (1989) 216-218.
[13] T.-N. Le, Y.-L. Lo, Effects of sulfur concentration and Marangoni convection on melt-pool formation in transition mode of selective laser melting process, Materials & Design, 179 (2019) 107866.
[14] S.A. Khairallah, A. Anderson, Mesoscopic simulation model of selective laser melting of stainless steel powder, Journal of Materials Processing Technology, 214(11) (2014) 2627-2636.
[15] D. Zhang, P. Zhang, Z. Liu, Z. Feng, C. Wang, Y. Guo, Thermofluid field of molten pool and its effects during selective laser melting (SLM) of Inconel 718 alloy, Additive Manufacturing, 21 (2018) 567-578.
[16] Y.P. Lei, H. Murakawa, Y.W. Shi, X.Y. Li, Numerical analysis of the competitive infuence of Marangoni fow and evaporation on heat surface temperature and molten pool shape in laser surface remelting, Computational Materials Science, 21 (2001) 276-290.
[17] T.-N. Le, Y.-L. Lo, Z.-H. Lin, Numerical simulation and experimental validation of melting and solidification process in selective laser melting of IN718 alloy, Additive Manufacturing, 36 (2020) 101519.
[18] K. Antony, N. Arivazhagan, Studies on energy penetration and Marangoni effect during laser melting process, Journal of Engineering Science and Technology, 10(4) (2015) 509-525.
[19] A.V. Gusarov, I. Yadroitsev, P. Bertrand, I. Smurov, Heat transfer modelling and stability analysis of selective laser melting, Applied Surface Science, 254(4) (2007) 975-979.
[20] J. Yin, H. Zhu, L. Ke, W. Lei, C. Dai, D. Zuo, Simulation of temperature distribution in single metallic powder layer for laser micro-sintering, Computational Materials Science, 53(1) (2012) 333-339.
[21] A. Hussein, L. Hao, C. Yan, R. Everson, Finite element simulation of the temperature and stress fields in single layers built without-support in selective laser melting, Materials & Design, 52 (2013) 638-647.
[22] Y. Li, D. Gu, Parametric analysis of thermal behavior during selective laser melting additive manufacturing of aluminum alloy powder, Materials & Design, 63 (2014) 856-867.
[23] K. Antony, N. Arivazhagan, K. Senthilkumaran, Numerical and experimental investigations on laser melting of stainless steel 316L metal powders, Journal of Manufacturing Processes, 16(3) (2014) 345-355.
[24] Y. Tian, L. Yang, D. Zhao, Y. Huang, J. Pan, Numerical analysis of powder bed generation and single track forming for selective laser melting of SS316L stainless steel, Journal of Manufacturing Processes, 58 (2020) 964-974.
[25] Y.S. Lee, W. Zhang, Mesoscopic Simulation of Heat Transfer and Fluid Flow in Laser Powder Bed Additive Manufacturing, in: International Solid Freeform Fabrication Symposium, University of Texas, Austin, Texas, 2015, pp. 1154-1165.
[26] Y. Huang, L.J. Yang, X.Z. Du, Y.P. Yang, Finite element analysis of thermal behavior of metal powder during selective laser melting, International Journal of Thermal Sciences, 104 (2016) 146-157.
[27] K. Zeng, D. Pal, B. Stucker, A review of thermal analysis methods in Laser Sintering and Selective Laser Melting, in: International Solid Freeform Fabrication Symposium, Austin, Texas, 2012, pp. 796-814.
[28] L. Dong, A. Makradi, S. Ahzi, Y. Remond, Three-dimensional transient finite element analysis of the selective laser sintering process, Journal of Materials Processing Technology, 209(2) (2009) 700-706.
[29] I. Yadroitsev, P. Bertrand, I. Smurov, Parametric analysis of the selective laser melting process, Applied Surface Science, 253(19) (2007) 8064-8069.
[30] E. Yasa, J.P. Kruth, J. Deckers, Manufacturing by combining Selective Laser Melting and Selective Laser Erosion/laser re-melting, CIRP Annals - Manufacturing Technology, 60(1) (2011) 263-266.
[31] E. Yasa, J. Deckers, J.P. Kruth, The investigation of the influence of laser re‐melting on density, surface quality and microstructure of selective laser melting parts, Rapid Prototyping Journal, 17(5) (2011) 312-327.
[32] J.D. Madison, L.K. Aagesen, Quantitative characterization of porosity in laser welds of stainless steel, Scripta Materialia, 67(9) (2012) 783-786.
[33] J. Metelkova, Y. Kinds, K. Kempen, C. de Formanoir, A. Witvrouw, B. Van Hooreweder, On the influence of laser defocusing in Selective Laser Melting of 316L, Additive Manufacturing, 23 (2018) 161-169.
[34] U.S. Bertoli, A.J. Wolfer, M.J. Matthews, J.-P.R. Delplanque, J.M. Schoenung, On the limitations of Volumetric Energy Density as a design parameter for Selective Laser Melting, Materials & Design, 113 (2017) 331-340.
[35] J.P. Kruth, M. Badrossamay, E. Yasa, J. Deckers, L. Thijs, J. Van Humbeeck, Part and material properties in selective laser melting of metals, in: International Symposium on Electromachining, Shanghai, China, 2010.
[36] D. Wang, Y. Yang, X. Su, Y. Chen, Study on energy input and its influences on single-track,multi-track, and multi-layer in SLM, The International Journal of Advanced Manufacturing Technology, 58(9-12) (2012) 1189-1199.
[37] J. Delgado, J. Ciurana, C.A. Rodríguez, Influence of process parameters on part quality and mechanical properties for DMLS and SLM with iron-based materials, The International Journal of Advanced Manufacturing Technology, 60(5-8) (2012) 601-610.
[38] A.B. Spierings, N. Herres, G. Levy, Influence of the particle size distribution on surface quality and mechanical properties in AM steel parts, Rapid Prototyping Journal, 17(3) (2011) 195-202.
[39] S.A. Khairallah, A.T. Anderson, A. Rubenchik, W.E. King, Laser powder-bed fusion additive manufacturing: Physics of complex melt flow and formation mechanisms of pores, spatter, and denudation zones, Acta Materialia, 108 (2016) 36-45.
[40] C. Panwisawas, C. Qiu, M.J. Anderson, Y. Sovani, R.P. Turner, M.M. Attallah, J.W. Brooks, H.C. Basoalto, Mesoscale modelling of selective laser melting: Thermal fluid dynamics and microstructural evolution, Computational Materials Science, 126 (2017) 479-490.
[41] W. Ge, S. Han, S.J. Na, J.Y.H. Fuh, Numerical modelling of surface morphology in selective laser melting, Computational Materials Science, 186 (2021) 110062.
[42] C. Kamath, B. El-dasher, G.F. Gallegos, W.E. King, A. Sisto, Density of additively-manufactured, 316L SS parts using laser powder-bed fusion at powers up to 400 W, The International Journal of Advanced Manufacturing Technology, 74(1-4) (2014) 65-78.
[43] O. Lopez-Botello, U. Martinez-Hernandez, J. Ramírez, C. Pinna, K. Mumtaz, Two-dimensional simulation of grain structure growth within selective laser melted AA-2024, Materials & Design, 113 (2017) 369-376.
[44] S. Ancellotti, V. Fontanari, A. Molinari, E. Iacob, P. Bellutti, V. Luchin, G. Zappini, M. Benedetti, Numerical/experimental strategies to infer enhanced liquid thermal conductivity and roughness in laser powder-bed fusion processes, Additive Manufacturing, 27 (2019) 552-564.
[45] S. Liu, H. Zhu, G. Peng, J. Yin, X. Zeng, Microstructure prediction of selective laser melting AlSi10Mg using finite element analysis, Materials & Design, 142 (2018) 319-328.
[46] S. Safdar, A.J. Pinkerton, L. Li, M.A. Sheikh, P.J. Withers, An anisotropic enhanced thermal conductivity approach for modelling laser melt pools for Ni-base super alloys, Applied Mathematical Modelling, 37(3) (2013) 1187-1195.
[47] A.B. Spierings, G. Levy, Comparison of density of stainless steel 316L parts produced with selective laser melting using different powder grades, in: International Solid Freeform Fabrication Symposium, Austin, Texas, 2009, pp. 342-353.
[48] R. Klein, Laser welding of plastics: Materials, processes and industrial applications, Wiley-VCH, 2011.
[49] 楊隆昌, 雷射發展的趨勢與應用, 中工高雄會刊, (2014).
[50] 劉國基, 張百齊, Nd-YAG 雷射的加工應用, 遠東學報, (2001) 372-296.
[51] D. Schwartz, Head and optics innovations key to laser cutting growth, in: The Fabricator, 2016.
[52] M.G. CVI, Gaussian beam optics, CVI Melles Griot 2009 Technical Guide, 2(1) (2009) 2.1-2.14.
[53] C.-H. Chu, Studies on melting heat transfer in rectangular latent-heat thermal control device, National Cheng Kung University, 1993.
[54] Ansys, Ansys fluent. 15.0 theory guide, ANSYS Inc., 2013.
[55] V.R. Voller, C. Prakash, A fixed grid numerical modelling methodology for convection-diffusion mushy region phase-change problems, International Journal of Heat and Mass Transfer, 30 (1987) 1709-1719.
[56] K.C. Mills, Fe-316 stainless steel, in: Recommended Values of Thermophysical Properties for Selected Commercial Alloys, Woodhead Publishing, 2002, pp. 135-142.
[57] B.V. L'vov, Thermal decomposition of solids and melts: new thermochemical approach to the mechanism, kinetics and methodology, Springer, 2007.
[58] M. Ritchie, S.L. Cockcroft, P.D. Lee, A. Mitchell, T. Wang, X-ray-based measurement of composition during electron beam melting of AISI 316 stainless steel: Part I. Experimental setup and processing of spectra, Metallurgical and Materials Transactions A, 34A (2003) 851-861.
[59] Z. Zhang, Modeling of Al evaporation and Marangoni flow in electron beam button melting of Ti-6Al-4V, The University of British Columbia Vancouver, Canada, 2013.
[60] T.C. Chawla, D.L. Graff, R.C. Borg, G.L. Bordner, D.P. Weber, D. Miller, Thermophysical properties of mixed oxide fuel and stainless steel type 316 for use in transition phase analysis, Nuclear Engineering and Design, 67 (1981) 57-74.
[61] C.D. Boley, S.A. Khairallah, A.M. Rubenchik, Calculation of laser absorption by metal powders in additive manufacturing, Applied optics, 54(9) (2015) 2477-2482.
[62] A. Rubenchik, S. Wu, S. Mitchell, I. Golosker, M. LeBlanc, N. Peterson, Direct measurements of temperature-dependent laser absorptivity of metal powders, Applied optics, 54(24) (2015) 7230-7233.
[63] C.D. Boley, S.C. Mitchell, A.M. Rubenchik, S.S. Wu, Metal powder absorptivity: modeling and experiment, Applied optics, 55(23) (2016) 6496-5000.
[64] J. Zhou, Y. Zhang, J.K. Chen, Numerical simulation of random packing of spherical particles for powder-based additive manufacturing, Journal of Manufacturing Science and Engineering, 131(3) (2009) 031004.
[65] D. Moser, S. Pannala, J. Murthy, Computation of effective radiative properties of powders for selective laser sintering simulations, JOM, 67(5) (2015) 1194-1202.
[66] T. Bell, Type 316 and 316L stainless steels, in, https://www.thoughtco.com, 2020.
[67] J.C. Chen, Y.C. Huang, Thermocapillary flows of surface melting due to a moving heat flux, International journal of heat and mass transfer, 34(3) (1991) 663-671.
[68] N. Saranjam, S. Chandra, J. Mostaghimi, H. Fan, J. Simmer, Orange peel formation due to surface tension-driven flows within drying paint films, Journal of Coatings Technology and Research, 13(3) (2016) 413-426.
[69] M.F. Schatz, G.P. Neitzel, Experiments on thermocapillary instabilities, Annual Review of Fluid Mechanics, 33(1) (2001) 93-127.
[70] Ansys, Ansys fluent. 15.0 UDF manual, ANSYS Inc., 2013.
[71] Tongtai, in, Tongtai Machine & Tool Co., Ltd., https://www.tongtai.com.tw/.
[72] Olympus, Olympus BX2M/BX51 brochure, Olympus Corporation, https://www.olympus-global.com/.
[73] E. Assuncao, S. Williams, Effect of material properties on the laser welding mode limits, Journal of Laser Applications, 26(1) (2014) 012008.
[74] Y.-H. Siao, C.-D. Wen, Influence of process parameters on heat transfer of molten pool for selective laser melting, Computational Materials Science, 193 (2021) 110388.
[75] Y.-H. Siao, C.-D. Wen, Examination of molten pool with Marangoni flow and evaporation effect by simulation and experiment in selective laser melting, International Communications in Heat and Mass Transfer, 125 (2021) 105325.
[76] Y.-H. Siao, C.-D. Wen, Thermal analysis of anisotropic heat conduction model with experimental validation on molten pool during selective laser melting, Materials Today Communications, 27 (2021) 102425.

校內：2025-08-20公開
校外：2025-08-20公開

簡易檢索 / 詳目顯示

相關論文