Optimal parameter ranges of material removal depth of abrasive cloth wheel polishing based on sensitivity analysis

Uniform material removal depth has an important influence on the profile accuracy and surface quality of the blisk blades in polishing. In order to guarantee the consistence of the polishing removal depth, a preferred method of polishing process parameter range based on sensitivity analysis is proposed. Firstly, the sensitive process parameters of polishing material removal depth were determined by four-factor three-level orthogonal experiments. Then, the three-factor central composite sequential (CCD) design experiment in the response surface method is used to obtain the quadratic regression empirical prediction model of polishing depth by multilinear regression through Minitab software, and the polishing material removal depth prediction model is analyzed significantly. Secondly, a mathematical model of relative sensitivity is established to determine the method of dividing the stable and unsteady domains of the process parameters, and the stable domain of each polishing process parameter and the sensitivity to the polishing removal depth were obtained. Finally, the comparative experiment verification was carried out by blisk polishing. Abrasive cloth wheel which is 12 mm in diameter and P 600# in abrasive size and has abrasive of Green Sic is used to the polishing of TC4 titanium alloy blade. The results show that the optimal stability ranges of significant parameters through sensitivity analysis are as follows: compression amount within [0.6 mm, 0.8 mm], rotation speed within [5000 r/min, 6000 r/min] and feed speed within [200 mm/min, 400 mm/min]. The depth of polishing in the stable domain is the most sensitive to the compression amount, followed by the speed, and the feed speed sensitivity is the lowest. The optimized polishing process parameters effectively reduce the fluctuation of the removal depth, and the surface quality has greatly improved by using the optimized polishing parameters.