信噪比与灰色关联分析选区激光烧结成型工艺的研究

Study on Selective Laser Sintering Process Based on Signal-to-Noise Ratio and Grey Correlation Analysis

针对选区激光烧结制件收缩率大,精度较低的问题,利用信噪比与灰色关联度相结合的选区激光烧结(SLS)工艺参数优化方法,提高尺寸精度。以制件X、Y、Z三个方向尺寸收缩率为目标函数,基于正交试验结果,采用信噪比和灰色关联分析的方法,得到工艺参数对目标函数的影响程度,同时将多目标优化问题转化为单目标优化问题,获得最佳工艺参数组合。结果表明,最佳的工艺参数组合为,激光功率为25 W,扫描速度为2200 mm/s,单层厚度为0.19 mm,扫描间距为0.31 mm。此时X/Y/Z向尺寸精度为:0.803%、0.817%、1.305%。将信噪比与灰色关联度相结合的优化方法应用到SLS工艺中,能够有效提高制件精度。

Aiming at the problem of large shrinkage and poor precision of selective laser sintering parts,the method of optimizing the parameters of selective laser sintering(SLS) process in combination with the signal-to-noise ratio and the gray correlation degree was proposed to improve the dimensional accuracy.Taking the dimensional shrinkage of the parts in X,Y and Z direction as the objective function,on the basis of the results of orthogonal experiments,the signal-to-noise ratio and grey-gray correlation analysis were used to obtain the influence degree of the process parameters on the objective function.At the same time,the multi-objective optimization problem was transformed into single-objective optimization to obtain optimal process parameter combination.The results show that the optimal combination of process parameters are as below:25 W laser power,2 200 mm/s scanning speed,0.19 mm single layer thickness,0.31 mm scanning pitch,and the X/Y/Z direction dimensional accuracy could be 0.803%,0.817%,1.305%.The optimization method combining the signal-to-noise ratio and the gray correlation degree was applied to the SLS process,which could effectively improve the precision of the workpiece.