【作者】 杨红梅；

【导师】 骆俊廷； 高士友；

【作者基本信息】 燕山大学 ， 材料加工工程， 2011， 硕士

【摘要】 激光熔覆技术是通过在基材表面添加熔覆材料,并利用高能量密度的激光束使之与基材表面薄层一起熔凝的方法,在基材表面与熔覆层形成冶金结合的同时,使金属表面能够获得高的耐磨性、耐高温性以及抗氧化等综合性能。本文采用实验研究和理论分析相结合的方法对激光熔覆多相复合材料的工艺和显微组织结构等方面进行了研究,得到了微纳米增强金属基复合涂层激光熔覆工艺的基本参数和涂层的微观组织以及对力学性能的影响规律。在Q235钢基体表面上以不同工艺参数单道熔覆了厚度均匀的316L不锈钢粉。分别从熔覆层宏观质量与微观质量和工艺参数之间关系来分析探讨,研究了激光功率、激光扫描速度以及铺粉厚度的的变化对该材料熔覆层的表面质量、稀释率、熔覆层气孔以及对显微组织的影响,并通过优化得到适合熔覆316L不锈钢粉末的工艺参数,即功率P=1.5 kw,扫描速度V=5 mm/s,铺粉厚度S=1 mm,在此参数下,熔覆层表面光滑致密、稀释率小、气孔少且与基体实现良好的冶金结合。以得到的优化工艺参数为基础,熔覆了掺有不同百分比的微米级碳化硅陶瓷粉的316L不锈钢粉和掺有不同百分比的纳米级碳化硅陶瓷粉的316L不锈钢粉,并分别得到熔覆试样。通过对试样宏观质量的分析,得到熔覆层材料的合理配比。对于成形较好的熔覆试样,分别通过金相组织观察、电镜扫描SEM及EDS、显微硬度以及XRD物相分析。得到了添加不同比例陶瓷增强相对熔覆层的表面质量、显微硬度和显微组织的影响规律。更多还原

【Abstract】 Laser cladding is the method of using high energy density laser beam to coagulate cladding material to matrix surface. The metallurgical combination can be formed between matrix surface and cladding layer, at the same time, the comprehensive performance of high wear resistance, high temperature resistant, and antioxidant etc. can be deserved for fabricated materials when the technology is applied.The process and microstructure structure of laser cladding multiphase composite materials were researched by experiment investigation and theoretical analysis in this paper. The basic parameters of nano-reinforced metal matrix coating fabricated by laser, the microstructure of the coating and the influence law to the mechanical properties were obtained.Laser clad on the surface of Q235 steel substrate with different process parameters to get the single-channel cladding of uniform thickness 316L stainless steel powder. The papers respectively analyze and discuss the relationship between the cladding layers macro quality and micro quality with the technology parameters. Study the influence law of the laser power, scanning speed and shop power thickness to surface quality, diluted rate, stomatal quantity and microstructure of the material cladding layers. and find out the suitable parameters for cladding 316L stainless steel powder technology, such as power P = 1.5 kw, scanning speed V = 5 mm/s, spread powder thickness S = 1 mm, using this parameter, Cladding layer surface smooth and compact, small dilute rate, less stomatal and formed good metallurgical combination with the base metal.Based on the process parameter obtained above, laser clad the 316L stainless steel powder mixed with different percentage of micro-structured ceramic powder of silicon carbide and mixed with different percentage of nano-scale sic ceramics powder, and separately get cladding specimens. After the sample quality analyzing, the reasonable matching of cladding layers material is got. For the good cladding specimens formed, respectively through the microstructure, scanning electronic microscopy SEM and EDS, micro-hardness and XRD object analyzing. Finally, getting the influence law to the surface quality, microhardness and microstructure of cladding layer adding different proportions ceramic reinforced phase.更多还原