高沉积率激光金属沉积Inconel 718的孔隙率控制

发布时间：2018-05-11 05:23

本文选题：激光加工 + 激光金属沉积　；参考：《光学精密工程》2015年11期

【摘要】：为降低高沉积率激光金属沉积(Laser Metal Deposition,LMD)工艺中材料的孔隙率,研究了以镍基高温合金Inconel 718(IN718)为粉末沉积材料的高沉积率LMD工艺中主要工艺参数对材料孔隙率的影响,以及通过调整工艺参数降低材料孔隙率的方法。以目标沉积率为2kg/h的LMD工艺为基础,通过参数固化和分离的手段开展了高沉积率LMD的镀层实验,研究了主要工艺参数即激光功率、扫描速度及送粉量对LMD镀层材料孔隙率的影响,分析了不同参数下各镀层的横截面孔隙率及镀层孔隙率。实验显示:当激光功率从1 440 W增加到4 214 W时,镀层材料的孔隙率从约1.5%降低至0.02%左右;当扫描速度为500mm/min至5 000mm/min时,镀层材料孔隙率始终保持为0.07%至0.18%左右;当送粉量从0.64kg/h增加至6.48kg/h时,镀层材料孔隙率从约0.01%增加至0.84%左右。可见在高沉积率LMD工艺中,扫描速度对材料孔隙率无明显影响,而提高激光功率、限制送粉量均可有效降低LMD材料孔隙率,提高横截面孔隙率的一致性。
[Abstract]:In order to reduce the porosity of materials in laser Metal deposition (LMD) process with high deposition rate, the effect of main process parameters on porosity of Ni-base superalloy Inconel 718 and IN718 was studied in this paper. And the method of reducing material porosity by adjusting process parameters. Based on the LMD process with target deposition rate of 2kg/h, the coating experiments of high deposition rate LMD were carried out by means of parameter solidification and separation. The main technological parameters, namely laser power, were studied. The effects of scanning speed and powder feeding amount on the porosity of LMD coating materials were studied. The cross section porosity and coating porosity of each coating under different parameters were analyzed. The experimental results show that when laser power is increased from 1 440 W to 4 214 W, the porosity of the coating material decreases from 1.5% to about 0.02%, and the porosity of the coating material keeps about 0.07% to 0.18% when the scanning speed is from 500mm/min to 5 000mm/min. The porosity of coating material increased from 0.01% to 0.84% when the powder feed rate increased from 0.64kg/h to 6.48kg/h. It can be seen that in the high deposition rate LMD process, the scanning rate has no obvious effect on the porosity of the material, but increasing the laser power and limiting the amount of powder feeding can effectively reduce the porosity of the LMD material and improve the consistency of the cross-section porosity.
【作者单位】：中国科学院长春光学精密机械与物理研究所;中国科学院大学;Fraunhofer激光技术研究所;
【基金】：欧盟AMAZE项目(No.313781)
【分类号】：TG174.4

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