基于三维打印的玻璃制品模具金属激光熔覆技术研究

发布时间：2018-12-06 20:39

【摘要】：激光熔覆技术具有稀释率低、热影响区小、效率高等优点,将其用于失效模具的修复有巨大的市场价值和应用前景。在模具表面进行激光熔覆可以提高模具的耐热、耐磨和耐腐蚀性,延长模具的使用寿命,从而获得更好的经济效益。本文基于三维打印中的激光熔融沉积(LMD)技术,采用理论分析和实验研究相结合的方法对激光熔覆的基础理论、工艺参数、宏观和微观组织性能等方面进行了较为深入的研究。本文具体内容如下:(1)以球墨铸铁为实验基材,熔覆粉末选用镍基合金,通过控制变量的方法,在激光功率密度或扫描速度恒定的条件下,研究工艺参数(功率1000W-2000W、扫描速度2mm/s-8mm/s)对熔覆层宏观及微观性能的影响。实验表明,在对比分析了不同参数下熔覆层的变化后,选用优化后的工艺参数,实现了对破损模具的表面修复。(2 )本文研究了搭接率对单层多道和多层多道的宏观容貌和熔覆性能的影响。分析了在激光熔覆的过程中,搭接率过大、适中和过小对熔覆道造成的三种成型情况。结果表明,选择与激光功率、送粉速率和扫描速度等参数相匹配的搭接率(约33%)有助于更好地实现多层和多道的熔覆搭接。(3 )通过金相显微镜和硬度计等仪器对熔覆层及其截面交界处的微观组织结构和硬度分布进行了深入的研究。分析了熔覆层缺陷的种类及出现的原因,并提出了针对不同原因导致的裂纹和气孔的解决方法。基于上述研究,本文采用优化后的熔覆参数在模具上进行表面修复,得到了初步的修复效果。
[Abstract]:Laser cladding technology has the advantages of low dilution rate, small heat affected zone and high efficiency. It has great market value and application prospect in repairing failure mould. Laser cladding on the surface of the mould can improve the heat resistance, wear resistance and corrosion resistance of the mould, prolong the service life of the mould and obtain better economic benefits. Based on the laser fused deposition (LMD) technology in 3D printing, the basic theory and process parameters of laser cladding are studied by combining theoretical analysis with experimental research. Macroscopical and microstructural properties were studied in detail. The main contents of this paper are as follows: (1) with nodular cast iron as the experimental substrate and nickel alloy as the cladding powder, the technological parameters (power 1000W-2000W) are studied under the condition of constant laser power density or scanning speed by controlling variables. The effect of scanning rate 2mm/s-8mm/s) on the macroscopic and microscopic properties of the cladding layer. The experimental results show that, after comparing and analyzing the change of cladding layer under different parameters, the optimized process parameters are selected. The surface repair of the damaged die is realized. (2) the effect of lap ratio on the macroscopic appearance and cladding performance of single layer and multi channel is studied. In the process of laser cladding, three kinds of forming conditions of cladding channel caused by overlapping rate, moderate rate and too small are analyzed. The results show that the selection of laser power, The overlap rate (about 33%) of the parameters such as powder feeding rate and scanning speed is helpful to better realize the multilayer and multichannel cladding. (3) the cladding layer and its cross section junction are obtained by means of metallographic microscope and hardness meter. The microstructure and hardness distribution were studied. The types and causes of defects in cladding layer are analyzed, and the solutions to crack and porosity caused by different reasons are put forward. Based on the above research, the optimized cladding parameters were used to repair the surface of the die, and a preliminary restoration effect was obtained.
【学位授予单位】：南京师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TQ171.68

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