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基于光内同轴送粉激光快速成形工艺,建立了熔池温度场瞬态有限元模型,对占空比K(环形光内外径之比)可变的环形激光光内送粉的熔池温度场的数值模拟表明:占空比的变化对环形激光光内送粉熔池的形状、大小和能量密度分布有很大影响。在相同工艺参数条件下,取K为0、0.35、0.6分别进行单层熔覆实验,对比CCD熔池图像与对应温度场云图,结果显示:各熔池形貌与对应的数值模拟温度场云图比较一致,从而印证了数值模拟的正确性。实验表明:K为0.35的环形光所得的熔覆层微观组织较佳,熔覆层与基体的冶金结合效果较好。
A transient finite element model of the temperature field of molten pool was established based on the laser coaxial rapid powder laser forming process. The temperature of the molten pool in the ring laser with variable duty ratio K (the ratio of annular inner diameter to outer diameter) The numerical simulation of the field shows that the change of the duty ratio has a great influence on the shape, size and energy density distribution of the powder feeding tank in the annular laser light. Under the same process parameters, taking K as 0,0.35,0.6, respectively, single-layer cladding experiments were carried out to compare the CCD image of the molten pool and the corresponding temperature field cloud image. The results show that the shape of the molten pool and the corresponding numerical simulation temperature field cloud image More consistent, which confirms the correctness of numerical simulation. The experimental results show that the microstructure of the cladding layer obtained by ring light with K of 0.35 is better, and the metallurgical bonding between the cladding layer and the substrate is better.