Nd : YAG雷射切割Inconel 718參數最佳化模式之探討

A Study on the Optimum Parameters Model in Nd : YAG Laser Cutting Inconel 718

廖愛華(Ai-Hua Liao)

指導教授 ： 簡文通

國立屏東科技大學/工學院/機械工程系所/碩士(2008年)

https://doi.org/10.6346/NPUST.2008.00006

摘要

本研究是利用Nd：YAG 雷射對Inconel 718鎳基合金薄板進行切割，探討雷射切割參數對切割後的表面粗糙度、熔渣高度及錐度之品質特性，並建立單一及多重目標品質之參數最佳化模式。研究流程可分為實驗架構、單一及多重目標品質之參數最佳化分析等階段。首先利用田口法直交表規劃實驗配置，選用尖峰功率、脈衝寬度、脈衝頻率、切割速度、聚焦位置及氣體壓力等為雷射切割參數。以表面粗糙度、熔渣高度及錐度等切割品質為量測對象，並藉由田口法分別選用雷射切割品質為各單一目標，以求取雷射切割參數最佳化組合。應用田口法多重目標品質分析，求出多重目標品質參數最佳化組合。接著利用田口法及灰關聯分析，找出以表面粗糙度、熔渣高度及錐度為多重目標品質之參數最佳化組合。結果顯示在單一目標品質參數最佳化分析中，分別得到切割處表面粗糙度為6.003 m、熔渣高度為0.104 mm及錐度為5.54°。在田口法多重目標品質參數最佳化分析中，得到切割處表面粗糙度為9.248 m、熔渣高度為0.208 mm及錐度為6.43°。當加入灰關聯分析後，可得到直交表內灰關聯分析之切割處表面粗糙度為8.799 m、熔渣高度為0.162 mm及錐度為5.80°。其中田口法多重目標品質之參數最佳化分析和直交表外灰關聯分析，所得參數最佳化組合結果相同。多重目標品質分析結果相較下以直交表內灰關聯分析為最佳。同時可推論單一及多重目標品質參數最佳化模式均可做為雷射切割相關研究的參考，並提供雷射切割相關產業參考及應用。

關鍵字

雷射切割 ； Inconel 718 ； 田口法 ； 灰關聯分析

並列摘要

The purpose of this study is to investigate the characteristics of quality to surface roughness, dross height of workpiece and cutted taper in laser cutting Inconel 718 by Nd:YAG, and construct the optimized parameters model for single and multiple quality objectives. Research procedure can be divided into experimental frame, the optimum parameters analysis of the single and multiple quality objectives stage. Firstly, an orthogonal array of Taguchi method is used to arrange the experimental configuration. The selected laser cutting parameters include peak power, impulse width, impulse frequency, cutting speed, focusing point and gas pressure. The cutting qualities of surface roughness, dross height of workpiece and cutted taper are measured and then the optimum laser cutting parameter set for the single objective of cutting qualities can be found by using Taguchi method, respectively. Furthermore, apply the multiple quality objectives analysis of Taguchi method to find the optimum parameter set of the multiple quality objectives. Continually, combining these three cutting qualities of the multiple objectives to seek out the optimum parameter set can be conducted by Taguchi method incorporate with grey relational analysis. The results of analysis show that the surface roughness is 6.003 m, dross height is 0.104 mm and cutted taper is 5.54°in the single quality objective analysis by using Taguchi method. The surface roughness is 9.248 m, dross height is 0.208 mm and cutted taper is 6.43°in the optimum parameters analysis of the multiple quality objectives, by using Taguchi method. Finally, after with grey relational analysis, it can be found that the surface roughness is 8.799 m, dross height is 0.162 mm and cutted taper is 5.80°in the orthogonal array of grey relational analysis. One of the optimum parameters analysis of the multiple quality objectives, by using Taguchi method and out of the orthogonal array of grey relational analysis, get the same of parameters. After comparison the orthogonal array of grey relational analysis to obtain the optimum results. Could deduce from the optimized parameters model of single and multiple quality objectives are good enough for the relational research in laser cutting and could be used for practical applications in related industry.

並列關鍵字

Laser Cutting ； Inconel 718 ； Taguchi Method ； Grey Relational Analysis

參考文獻

[24]C. B. Chen, C. T. Lin, C. W. Chang, and C. P. Ho, 2000, “Grey Relation for Solving Multi-Quality characteristics Problems of Taguchi Methods,” Journal of Technology, Vol. 15, No.1, pp. 25-33.

[25]C. H. Tsai, and H. W. Chen, 2003, “Laser cutting of thick ceramic substrates by controlled fracture technique,” Journal of Materials Processing Technology, Vol.136, p.p.166-173.

[26]C. Karatas, O. Keles, I. Uslan, and Y. Usta, 2006, “Laser cutting of steel sheets: Influence of workpiece thickness and beam waist position on kerf size and stria formation,” Journal of Materials Processing Technology, Vol.172, p.p.22-29.

[27]G.K.L. Ngand L. Li, 2003, “Repeatability characteristic of laser percussion drilling of stainless-steel sheets,” Optics & Laser Technology, Vol. 39, pp. 25-33.

[28]G.Thawari, J. K. Sarin Sundar, G. Sundararajan, and S. V. Joshi, 2005, “Influence of process parameters during pulsed Nd:YAG laser cutting of nickel-base superalloys,” Journal of Materials Processing Technology, Vol.170, p.p.229-239.