环形激光作用下同轴送粉熔覆工艺参数对成形的影响
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摘要
激光熔覆快速成形技术是在激光熔覆技术的基础上,结合快速成形制造的特点发展起来的一种先进制造技术。目前激光熔覆快速成形技术普遍采用的送粉方式为偏置侧向送粉和多粉管光外同轴送粉,激光光斑为圆形光斑,在这种送粉方式下,光斑和粉斑的耦合稳定性比较差,本文采用环形激光光内同轴送粉的方式进行激光熔覆快速成形,重点对光内送粉工艺参数对成形的影响进行了分析研究。
通过建立环形激光束与光内同轴送粉粉束相互作用的简化数学模型,以作用区域的粉末为研究对象,重点讨论了环形激光作用效率η。经计算,同一z坐标处的η随送粉量M_p( g / s)的增大而增大,随粉流速度v_0的增大而减小;送粉量M_p和粉流速度v_0一定时,η随z的增大而增大。分析了环形激光光斑在扫描线宽方向能量的分布情况,与传统的圆形光斑和矩形光斑相比,有利于能量的合理分布和提高激光热作用效应;讨论了环形激光熔覆成形中主要工艺参数,如环形激光功率密度、扫描速度、送粉速率和光斑直径等对成形的影响。
利用环形激光光内同轴送粉喷头进行了多模激光束下单道单层、单道多层,离焦和多道搭接熔覆实验和测试。研究了在环形激光作用下激光功率、扫描速度、搭接量、送粉速率、光斑直径等工艺参数对成形尺寸、形貌、显微组织的影响,分析了不同工艺参数与熔覆层质量的关系。结果表明:要获得较好的成形质量,搭接量应大于光斑半径,激光功率、扫描速度和送粉速率存在着最佳匹配值,环形光斑下的正负离焦量可达14 mm,能够在离焦状态下实现较高质量的激光熔覆快速成形。试验证明,与圆形光外同轴送粉成形工艺相比,环形激光束与粉末耦合性好,激光光斑充分包围粉斑,成形件表面光洁度高,侧面无未熔化颗粒;环形激光热作用充分,其显微组织致密无缺陷,熔覆层边界与基体结合情况良好。
Laser cladding rapid prototyping bases on laser cladding is an advanced manufacturing technology, which was developed from rapid prototyping(RP). At present, the widely used method of powder feeding is lateral powder feeding and coaxial powder feeding process. This paper aims at studying the laser cladding rapid prototyping parts by annular laser facula and inside-laser coaxial powder feeding device to optimize the laser processing parameters.
This paper establishes the simplified mathematics model of laser and powder reciprocity in the inside-laser coaxial powder feeding process and deduces the calculation formula of laser effect efficiency. Through theoretically calculation, at the same coordinate, laser effect efficiency increases with powder feeding quantity rising and powder velocity decreasing. When powder feeding quantity being an invariable numerical value, laser effect efficiency increases with a powder granule’s time increasing in laser, which corresponds to the former study. This paper also analyses the energy distribution of annulus laser facula, the annulus laser facula is much propitious to shaped than traditional circular or rectangular facula; discusses the key process parameters that needed in the thin wall shaped parts experiment, such as laser power density, beam of light mode and scanning speed etc.
Through several monolayer line scanning cladding experiment, multilayer line scanning cladding experiment, lines overlapping scanning cladding experiment in the multimode laser, analyzed their microscopic structure、hardness of shaped metallic parts. To obtain the parts with high precision and the excellent quality, the influence of many processing parameters on sizes of cladding coatings, precision and surface quality has been analyzed in detailed. These parameters include: laser power, scanning speed and ratio of overlapped. The results show that for getting the parts with best quality by, the value of overlapping ratios should be greater than that of the spot sizes. And furthermore, the optimum matching of laser power, scanning speed powder delivery speed is necessary, it is impossible to produce the high-grade laser cladding rapid prototyping parts within 14 mm determinate defocusing.
The experiment results shows that the coupled performance of laser and powder reciprocity is excellent, the surface of parts is smooth, heat action of annular facula laser is sufficient, compared with the former prototyping process. Ultimately,the article analyses microscopic structure and hardness of shaped metallic parts. The microscopic structure is dense and has no defects and the hardness of shaped metallic parts enhances greatly.
通过建立环形激光束与光内同轴送粉粉束相互作用的简化数学模型,以作用区域的粉末为研究对象,重点讨论了环形激光作用效率η。经计算,同一z坐标处的η随送粉量M_p( g / s)的增大而增大,随粉流速度v_0的增大而减小;送粉量M_p和粉流速度v_0一定时,η随z的增大而增大。分析了环形激光光斑在扫描线宽方向能量的分布情况,与传统的圆形光斑和矩形光斑相比,有利于能量的合理分布和提高激光热作用效应;讨论了环形激光熔覆成形中主要工艺参数,如环形激光功率密度、扫描速度、送粉速率和光斑直径等对成形的影响。
利用环形激光光内同轴送粉喷头进行了多模激光束下单道单层、单道多层,离焦和多道搭接熔覆实验和测试。研究了在环形激光作用下激光功率、扫描速度、搭接量、送粉速率、光斑直径等工艺参数对成形尺寸、形貌、显微组织的影响,分析了不同工艺参数与熔覆层质量的关系。结果表明:要获得较好的成形质量,搭接量应大于光斑半径,激光功率、扫描速度和送粉速率存在着最佳匹配值,环形光斑下的正负离焦量可达14 mm,能够在离焦状态下实现较高质量的激光熔覆快速成形。试验证明,与圆形光外同轴送粉成形工艺相比,环形激光束与粉末耦合性好,激光光斑充分包围粉斑,成形件表面光洁度高,侧面无未熔化颗粒;环形激光热作用充分,其显微组织致密无缺陷,熔覆层边界与基体结合情况良好。
Laser cladding rapid prototyping bases on laser cladding is an advanced manufacturing technology, which was developed from rapid prototyping(RP). At present, the widely used method of powder feeding is lateral powder feeding and coaxial powder feeding process. This paper aims at studying the laser cladding rapid prototyping parts by annular laser facula and inside-laser coaxial powder feeding device to optimize the laser processing parameters.
This paper establishes the simplified mathematics model of laser and powder reciprocity in the inside-laser coaxial powder feeding process and deduces the calculation formula of laser effect efficiency. Through theoretically calculation, at the same coordinate, laser effect efficiency increases with powder feeding quantity rising and powder velocity decreasing. When powder feeding quantity being an invariable numerical value, laser effect efficiency increases with a powder granule’s time increasing in laser, which corresponds to the former study. This paper also analyses the energy distribution of annulus laser facula, the annulus laser facula is much propitious to shaped than traditional circular or rectangular facula; discusses the key process parameters that needed in the thin wall shaped parts experiment, such as laser power density, beam of light mode and scanning speed etc.
Through several monolayer line scanning cladding experiment, multilayer line scanning cladding experiment, lines overlapping scanning cladding experiment in the multimode laser, analyzed their microscopic structure、hardness of shaped metallic parts. To obtain the parts with high precision and the excellent quality, the influence of many processing parameters on sizes of cladding coatings, precision and surface quality has been analyzed in detailed. These parameters include: laser power, scanning speed and ratio of overlapped. The results show that for getting the parts with best quality by, the value of overlapping ratios should be greater than that of the spot sizes. And furthermore, the optimum matching of laser power, scanning speed powder delivery speed is necessary, it is impossible to produce the high-grade laser cladding rapid prototyping parts within 14 mm determinate defocusing.
The experiment results shows that the coupled performance of laser and powder reciprocity is excellent, the surface of parts is smooth, heat action of annular facula laser is sufficient, compared with the former prototyping process. Ultimately,the article analyses microscopic structure and hardness of shaped metallic parts. The microscopic structure is dense and has no defects and the hardness of shaped metallic parts enhances greatly.
引文
[1] 钟敏霖,宁国庆等.激光快速柔性制造金属零件基本研究.应用激光,2001,21(2):76—80
[2] 王雅先,尉富恩,王科峰.激光快速成形技术的应用.轻工机械,2006,24(4):143—145
[3] Jean-Claude Goussain, Cecile Mayer, Ahim Becker.et al. Microstructural evolution in high power laser cladding of Stellite 6+WC layers. Surface and Coatings Technology. 157 (2002): 128–137
[4] S. Sun, Y. Durandet, M. Brand. Parametric investigation of pulsed Nd: YAG laser cladding of stellite 6 on stainless steel. Surface & Coatings Technology, 194 (2005): 225– 231
[5] JM Pelletier et al. Microstructure and Mechanical Properties of some Metal Matrix Composites Coatings by Laser Cladding. Journal De Physique. 1994, 4(4): 93-96
[6] 王安安.在纯镁上激光熔覆镁铝合金层提高表面的耐蚀性.应用激光.1992,12: 245
[7] U. Ritter and W. Kahrmann. Laser Coating Proven in Practice. Surface Engineering. 1992, 8: 272
[8] B. C. Oberlander. Comparison of Properties of Coatings Produced by Laser Cladding and Conventional Methods. Materials Science and Technology. 1992, 8: 657
[9] B.S.Shin.A new rapid manufacturing process for multi-face high-speed machining.The international journal of advanced manufacturing technology. 2003, 22:68-74
[10] N.P. Karapatisect. Direct rapid tooling: a review of current research.Rapid Prototyping Jounrnal. 1998, 2(4): 77—89
[11] Lin J. et a1. Design characteristics and development of a nozzle for coaxial laser cladding[J].Journal of Laser Application,1998.10: 55—63
[12] 杨森,钟敏霖,张庆茂,刘文今.金属零件的直接快速制造.粉末冶金技术.2002, 8(20):234-238
[13] 尚晓峰,刘伟军,王天然,王志坚.激光工程化净成形技术的研究.工具技术.2004(38):22-25
[14] 李会山,王惠滨,王冬涛.高能束激光直接制造金属零件技术的进展.金属热处理 2006(z1):29-31
[15] 王建军.基于激光熔覆的快速制造技术的初步研究.[硕士学位论文] 天津:天津工业大学.2003,(5)
[16] 杨毅.激光直接快速成形金属零件的机理及工艺研究[D] .南华大学硕士论文.2006,5
[17] 张凯,刘伟军.金属零件激光直接快速成型技术的研究(上)—国外篇.工具技术,2005,39:3—8
[18] 陈静,杨海欧,杨健等.高温合金与钛合金的激光快速成形工艺研究.航空材料学报.2003,33(10): 100—103
[19] 黄卫东,李延民,冯莉萍等.金属材料激光立体成形技术.材料工程.2002,(3): 40—43
[20] 李延民,李建国,杨海欧等.金属零件激光直接成形.应用激光.2002,22(2): 140—144
[21] 张永忠,章萍芝,石力开等.金属零件激光快速成型技术研究.材料导报.2001,15(12):10—13
[22] 章萍芝,张永忠,石力开等.金属零件的激光直接成形研究.稀有金属.2001,25(2):114—117
[23] 席明哲,张永忠,石力开等.激光快速成型致密金属零件的研究.北京科技大学学报.2002,24(4):441—444
[24] 张凯,刘伟军等金属零件激光直接快速成形技术的研究(下)—国内篇.工具技术,2005,(39):3—5
[25] Yang Xichen, Zhao Xin, Wang Yunshan. New Development of Laser Cladding System on Large Area for Industrial Application (Invited Paper). The Proceeding of SPIE. 1996, 2888(6-7): 14-18
[26] Yang Xichen, Wang Yunshan, Zhao Xin. Development of Laser Repairing Parts in Metallurgical Industries in China. ICALEO’ 1999 Proceedings. Section A 67, 1999, San Diego, USA
[27] 杨洗陈,李会山,王云山等.用于重大装备修复的激光再制造技术.激光与电子学进展, 2003,40(10):53—57
[28] 杨洗陈,李会山,刘运武等.激光再制造技术及其工业应用.中国表面工程,2003,(4):43—46
[29] 尚晓峰,刘伟军,王天然.激光工程化净成形技术同轴送粉的研究.中国机械工程,2004,25(22):1994—1997
[30] 尚晓峰,刘伟军,王天然.激光工程化净成形技术的研究.工具技术.2004,38(1):22—25
[31] 王小兵,孙斌等.定向棱镜腔平顶高斯激光束特性的研究.激光技术.2002.26(2):117—119
[32] 王新洪,邹增大,曲仕尧.表面熔融凝固强化技术.化学工业出版社.北京.2005,(7): 96-99
[33] 杨洗陈,王云山,赵新,王宝琦.大面积激光自动涂敷系统及其工业应用.天津纺织工学院学报.1998,17(1):80-85
[34] 杨洗陈,王宝琦,王云山,赵新.万瓦级激光熔敷宽带扫描转镜的研究.光电子激光.1996,7(5):279-282
[35] 杨洗陈,王云山,孙荣禄.激光宽带淬火机理及应用研究.中国机械工程.2004,15(3):196-198
[36] 李明喜,何宜柱,孙国雄.Ni 基合金 45# 钢宽、窄带熔覆Co 基合金的组织.中国激光.2003,30(11):1044-1048
[37] 黄慧琴,赵承良,陆璇辉.空心光束的研究进展.激光与红外.2007,4(4):300-303
[38] 印建平,刘南春,夏勇,恽曼.空心光束的产生及其在现代光学中的应用.物理学进展.2004,9:336-380
[39] 高淑英.用于激光熔覆的同轴送粉喷嘴的设计及研究.[硕士学位论文] 天津:天津工业大学.2002.1
[40] 高淑英,杨洗陈.用于激光熔敷的同轴送粉喷嘴的设计.天津工业大学学报.2003.22(5)
[41] 王家金.激光加工技术.中国计量出版社.1992,第一版
[42] 刘江龙等,激光合金化的微观成分不均匀性的探讨[J],激光热处理.1990,3(11):25—28
[43] 张庆茂,刘文今,杨 森等.激光与熔覆粉末作用效率的计算及影响因[J].激光技术.2002,(3):170-172
[44] 郭伟,徐庆鸿,田锡唐.激光熔覆的研究发展状况.宇航材料工艺.1998,1:1-8
[45] 韩召,曹文斌等. 陶瓷材料的选区激光烧结快速成形技术研究进展.无机材料学报. 2004(4):705—712
[46] G. Chen, X. Xu, Experimental and 3D finite element studies of CW laser forming of thin stainless steel sheets. Journal of Manufacturing Science and Engineering. 123(2)(2001): 66-73
[47] Wohlers T. Rapid Prototyping & Tooling State of the Industry[C]. Second International Conference on Rapid Prototyping & Rapid Manufacturing. Beijing, China, 2002
[48] 钟敏霖,杨林等.激光快速直接制造 W/Ni 合金太空望远镜准直器.中国激光. 2004(4):482-486
[49] 张剑锋.Ni 基金属粉末激光直接烧结成形及关键技术研究.南京航空航天大学博士学位论 文.2001.35-40
[50] A. Simchi, H. Pohl. Effects of laser sintering processing parameters on the microstructure and densification of iron powder. Materials and Engineering A359(2003): 119-128
[51] G. K. Lewis, D. J. Thoma. Directed Light Fabrication of Refractory Metals[R]. international Conference on Powder Metallurgy and Particulate Materials. Chicago, Illinois, June, 29-July2, 1997.
[52] 程艳阶,史玉升等.选择性激光烧结复合扫描路径的规划与实现.机械科学与技术.2004(9):1072-1075
[53] 朱小蓉,任乃飞等.选择性激光烧结快速成形技术中材料的研究和应用现状.上海大学学报. 2004(80):41-45
[54] P. Fischer, N. Karapatis, V. Romano, R. Glardon, H. P. Weber, A model for the interaction of near-infrared laser pulses with metal powders in selective laser sintering. Applied Physics A 74(1) (2002): 467-474
[55] G. Bugeda, M. Cervera, G. Lombera. Numerical prediction of temperature and density distribution in selective laser sintering process. Rapid Prototyping Journal 5(1) (1999): 21-26
[56] 沈德久,廖波,王玉林.同轴送粉对激光熔覆组织的细化作用.应用激光.第22卷,2002年6月第3期:290-292
[57] 张庆茂.送粉激光熔覆应用基础理论的研究[D].中科院长春光学精密与物理研究所,2000.12
[58]D. Srivastava, I. T. H. Chang, M. H. Loretto. The Effect of Process Parameters and Heat Treatmeng on the Microstructure of Direct Laser Fabricated TiAl Alloy Samples. Intermetallics, 2001,(9): 1003-1013
[59] 刘文今,曾大本,黄惠松.稀土金属氧化物涂层对铸铁激光强化区组织和性能的影响.中国激光.1992,19(8):613-617
[60] Andrew J. Pinkerton, Lin Li. The significance of deposition point standoff variations in multiple-layer coaxial laser cladding(coaxial cladding standoff effects) International Journal of Machine Tools & Manufacture 44 (2004) :573–584
[61] 梁工英,贺柏龄,苏俊义等.铝合金激光熔覆 Ni-WC 涂层的组织及耐磨性.中国激光.1998,A26(10):950-954
[61] 田保红等.稀土氧化物和激光熔敷对复合合金喷涂层耐磨性的影响.焊接学报.1996,17(2):88-93
[62] 李强,雷廷权,孟庆昌等.激光熔覆 Ni-Cr-B-Si-C 合金涂层显微组织的透射电镜研究.中 国激光.1999,A26(4):372-378
[63] 查莹,周昌炽,唐西南等.改善激光熔覆镍基合金和陶瓷硬质相复合涂层性能的研究.中国激光.1999,A26(10):948-951
[64] M. Qian, L. C. Lim et al. Journal of Materials Processing Technology. 1997, 63: 590
[65] 宋武林,周刚,曾大文等.铁基合金中 Cr_(eq)/Ni_(eq)对其激光熔覆层组织结构和开裂敏感性的影响.激光技术.1999,23(3):142-145
[66] 宋武林,朱蓓蒂等.激光熔覆层结晶方向对覆层裂纹方向和开裂敏感性的影响.中国激光.1995,A22(4):309-312
[67] Frank A. Marsden C. F, Wanere J. D. et al. Surface and Coating Technology. 1991, 45: 435
[68] 陈传忠,王文中等.激光熔覆 Al_2O_3-NiCrAl 层的脆性及摩擦磨损特性.中国激光.1999,A26(9):841-844
[69] Y. Liu, J. Mazumder, K. Shibata. Metallurgical and Materials Transactions A. 1996, 26A: 1519
[70] 栾景飞,胡建东.激光熔覆参数对灭铸铁激光熔覆层裂纹的影响.应用激光.2000,20(2):53-56
[71] 宋武林,朱蓓蒂等.激光熔覆层热膨胀系数对其开裂敏感性的影响.华中理工大学学报(增刊Ⅰ)1999,27(9):42-44
[72] 陈俐,谢长生,胡木林等.激光熔覆用铁基合金工艺性研究.焊接技术.2001,30(3):2-4
[73] 郭伟,徐庆鸿,田锡唐.激光熔覆的研究发展状况.宇航材料工艺.1998,2:33-35
[74] 宋光明,吴钢,黄婉娟.单向送粉双向扫描激光熔覆工艺防止裂纹的试验研究.金属热处理.2005.30(5):25-27
[2] 王雅先,尉富恩,王科峰.激光快速成形技术的应用.轻工机械,2006,24(4):143—145
[3] Jean-Claude Goussain, Cecile Mayer, Ahim Becker.et al. Microstructural evolution in high power laser cladding of Stellite 6+WC layers. Surface and Coatings Technology. 157 (2002): 128–137
[4] S. Sun, Y. Durandet, M. Brand. Parametric investigation of pulsed Nd: YAG laser cladding of stellite 6 on stainless steel. Surface & Coatings Technology, 194 (2005): 225– 231
[5] JM Pelletier et al. Microstructure and Mechanical Properties of some Metal Matrix Composites Coatings by Laser Cladding. Journal De Physique. 1994, 4(4): 93-96
[6] 王安安.在纯镁上激光熔覆镁铝合金层提高表面的耐蚀性.应用激光.1992,12: 245
[7] U. Ritter and W. Kahrmann. Laser Coating Proven in Practice. Surface Engineering. 1992, 8: 272
[8] B. C. Oberlander. Comparison of Properties of Coatings Produced by Laser Cladding and Conventional Methods. Materials Science and Technology. 1992, 8: 657
[9] B.S.Shin.A new rapid manufacturing process for multi-face high-speed machining.The international journal of advanced manufacturing technology. 2003, 22:68-74
[10] N.P. Karapatisect. Direct rapid tooling: a review of current research.Rapid Prototyping Jounrnal. 1998, 2(4): 77—89
[11] Lin J. et a1. Design characteristics and development of a nozzle for coaxial laser cladding[J].Journal of Laser Application,1998.10: 55—63
[12] 杨森,钟敏霖,张庆茂,刘文今.金属零件的直接快速制造.粉末冶金技术.2002, 8(20):234-238
[13] 尚晓峰,刘伟军,王天然,王志坚.激光工程化净成形技术的研究.工具技术.2004(38):22-25
[14] 李会山,王惠滨,王冬涛.高能束激光直接制造金属零件技术的进展.金属热处理 2006(z1):29-31
[15] 王建军.基于激光熔覆的快速制造技术的初步研究.[硕士学位论文] 天津:天津工业大学.2003,(5)
[16] 杨毅.激光直接快速成形金属零件的机理及工艺研究[D] .南华大学硕士论文.2006,5
[17] 张凯,刘伟军.金属零件激光直接快速成型技术的研究(上)—国外篇.工具技术,2005,39:3—8
[18] 陈静,杨海欧,杨健等.高温合金与钛合金的激光快速成形工艺研究.航空材料学报.2003,33(10): 100—103
[19] 黄卫东,李延民,冯莉萍等.金属材料激光立体成形技术.材料工程.2002,(3): 40—43
[20] 李延民,李建国,杨海欧等.金属零件激光直接成形.应用激光.2002,22(2): 140—144
[21] 张永忠,章萍芝,石力开等.金属零件激光快速成型技术研究.材料导报.2001,15(12):10—13
[22] 章萍芝,张永忠,石力开等.金属零件的激光直接成形研究.稀有金属.2001,25(2):114—117
[23] 席明哲,张永忠,石力开等.激光快速成型致密金属零件的研究.北京科技大学学报.2002,24(4):441—444
[24] 张凯,刘伟军等金属零件激光直接快速成形技术的研究(下)—国内篇.工具技术,2005,(39):3—5
[25] Yang Xichen, Zhao Xin, Wang Yunshan. New Development of Laser Cladding System on Large Area for Industrial Application (Invited Paper). The Proceeding of SPIE. 1996, 2888(6-7): 14-18
[26] Yang Xichen, Wang Yunshan, Zhao Xin. Development of Laser Repairing Parts in Metallurgical Industries in China. ICALEO’ 1999 Proceedings. Section A 67, 1999, San Diego, USA
[27] 杨洗陈,李会山,王云山等.用于重大装备修复的激光再制造技术.激光与电子学进展, 2003,40(10):53—57
[28] 杨洗陈,李会山,刘运武等.激光再制造技术及其工业应用.中国表面工程,2003,(4):43—46
[29] 尚晓峰,刘伟军,王天然.激光工程化净成形技术同轴送粉的研究.中国机械工程,2004,25(22):1994—1997
[30] 尚晓峰,刘伟军,王天然.激光工程化净成形技术的研究.工具技术.2004,38(1):22—25
[31] 王小兵,孙斌等.定向棱镜腔平顶高斯激光束特性的研究.激光技术.2002.26(2):117—119
[32] 王新洪,邹增大,曲仕尧.表面熔融凝固强化技术.化学工业出版社.北京.2005,(7): 96-99
[33] 杨洗陈,王云山,赵新,王宝琦.大面积激光自动涂敷系统及其工业应用.天津纺织工学院学报.1998,17(1):80-85
[34] 杨洗陈,王宝琦,王云山,赵新.万瓦级激光熔敷宽带扫描转镜的研究.光电子激光.1996,7(5):279-282
[35] 杨洗陈,王云山,孙荣禄.激光宽带淬火机理及应用研究.中国机械工程.2004,15(3):196-198
[36] 李明喜,何宜柱,孙国雄.Ni 基合金 45# 钢宽、窄带熔覆Co 基合金的组织.中国激光.2003,30(11):1044-1048
[37] 黄慧琴,赵承良,陆璇辉.空心光束的研究进展.激光与红外.2007,4(4):300-303
[38] 印建平,刘南春,夏勇,恽曼.空心光束的产生及其在现代光学中的应用.物理学进展.2004,9:336-380
[39] 高淑英.用于激光熔覆的同轴送粉喷嘴的设计及研究.[硕士学位论文] 天津:天津工业大学.2002.1
[40] 高淑英,杨洗陈.用于激光熔敷的同轴送粉喷嘴的设计.天津工业大学学报.2003.22(5)
[41] 王家金.激光加工技术.中国计量出版社.1992,第一版
[42] 刘江龙等,激光合金化的微观成分不均匀性的探讨[J],激光热处理.1990,3(11):25—28
[43] 张庆茂,刘文今,杨 森等.激光与熔覆粉末作用效率的计算及影响因[J].激光技术.2002,(3):170-172
[44] 郭伟,徐庆鸿,田锡唐.激光熔覆的研究发展状况.宇航材料工艺.1998,1:1-8
[45] 韩召,曹文斌等. 陶瓷材料的选区激光烧结快速成形技术研究进展.无机材料学报. 2004(4):705—712
[46] G. Chen, X. Xu, Experimental and 3D finite element studies of CW laser forming of thin stainless steel sheets. Journal of Manufacturing Science and Engineering. 123(2)(2001): 66-73
[47] Wohlers T. Rapid Prototyping & Tooling State of the Industry[C]. Second International Conference on Rapid Prototyping & Rapid Manufacturing. Beijing, China, 2002
[48] 钟敏霖,杨林等.激光快速直接制造 W/Ni 合金太空望远镜准直器.中国激光. 2004(4):482-486
[49] 张剑锋.Ni 基金属粉末激光直接烧结成形及关键技术研究.南京航空航天大学博士学位论 文.2001.35-40
[50] A. Simchi, H. Pohl. Effects of laser sintering processing parameters on the microstructure and densification of iron powder. Materials and Engineering A359(2003): 119-128
[51] G. K. Lewis, D. J. Thoma. Directed Light Fabrication of Refractory Metals[R]. international Conference on Powder Metallurgy and Particulate Materials. Chicago, Illinois, June, 29-July2, 1997.
[52] 程艳阶,史玉升等.选择性激光烧结复合扫描路径的规划与实现.机械科学与技术.2004(9):1072-1075
[53] 朱小蓉,任乃飞等.选择性激光烧结快速成形技术中材料的研究和应用现状.上海大学学报. 2004(80):41-45
[54] P. Fischer, N. Karapatis, V. Romano, R. Glardon, H. P. Weber, A model for the interaction of near-infrared laser pulses with metal powders in selective laser sintering. Applied Physics A 74(1) (2002): 467-474
[55] G. Bugeda, M. Cervera, G. Lombera. Numerical prediction of temperature and density distribution in selective laser sintering process. Rapid Prototyping Journal 5(1) (1999): 21-26
[56] 沈德久,廖波,王玉林.同轴送粉对激光熔覆组织的细化作用.应用激光.第22卷,2002年6月第3期:290-292
[57] 张庆茂.送粉激光熔覆应用基础理论的研究[D].中科院长春光学精密与物理研究所,2000.12
[58]D. Srivastava, I. T. H. Chang, M. H. Loretto. The Effect of Process Parameters and Heat Treatmeng on the Microstructure of Direct Laser Fabricated TiAl Alloy Samples. Intermetallics, 2001,(9): 1003-1013
[59] 刘文今,曾大本,黄惠松.稀土金属氧化物涂层对铸铁激光强化区组织和性能的影响.中国激光.1992,19(8):613-617
[60] Andrew J. Pinkerton, Lin Li. The significance of deposition point standoff variations in multiple-layer coaxial laser cladding(coaxial cladding standoff effects) International Journal of Machine Tools & Manufacture 44 (2004) :573–584
[61] 梁工英,贺柏龄,苏俊义等.铝合金激光熔覆 Ni-WC 涂层的组织及耐磨性.中国激光.1998,A26(10):950-954
[61] 田保红等.稀土氧化物和激光熔敷对复合合金喷涂层耐磨性的影响.焊接学报.1996,17(2):88-93
[62] 李强,雷廷权,孟庆昌等.激光熔覆 Ni-Cr-B-Si-C 合金涂层显微组织的透射电镜研究.中 国激光.1999,A26(4):372-378
[63] 查莹,周昌炽,唐西南等.改善激光熔覆镍基合金和陶瓷硬质相复合涂层性能的研究.中国激光.1999,A26(10):948-951
[64] M. Qian, L. C. Lim et al. Journal of Materials Processing Technology. 1997, 63: 590
[65] 宋武林,周刚,曾大文等.铁基合金中 Cr_(eq)/Ni_(eq)对其激光熔覆层组织结构和开裂敏感性的影响.激光技术.1999,23(3):142-145
[66] 宋武林,朱蓓蒂等.激光熔覆层结晶方向对覆层裂纹方向和开裂敏感性的影响.中国激光.1995,A22(4):309-312
[67] Frank A. Marsden C. F, Wanere J. D. et al. Surface and Coating Technology. 1991, 45: 435
[68] 陈传忠,王文中等.激光熔覆 Al_2O_3-NiCrAl 层的脆性及摩擦磨损特性.中国激光.1999,A26(9):841-844
[69] Y. Liu, J. Mazumder, K. Shibata. Metallurgical and Materials Transactions A. 1996, 26A: 1519
[70] 栾景飞,胡建东.激光熔覆参数对灭铸铁激光熔覆层裂纹的影响.应用激光.2000,20(2):53-56
[71] 宋武林,朱蓓蒂等.激光熔覆层热膨胀系数对其开裂敏感性的影响.华中理工大学学报(增刊Ⅰ)1999,27(9):42-44
[72] 陈俐,谢长生,胡木林等.激光熔覆用铁基合金工艺性研究.焊接技术.2001,30(3):2-4
[73] 郭伟,徐庆鸿,田锡唐.激光熔覆的研究发展状况.宇航材料工艺.1998,2:33-35
[74] 宋光明,吴钢,黄婉娟.单向送粉双向扫描激光熔覆工艺防止裂纹的试验研究.金属热处理.2005.30(5):25-27