Suppressing the burr of high aspect ratio structure by optimizing the cutting parameters in the micro-milling process

High aspect ratio (HAR) structures are widely utilized in diverse applications, including the defense industries, medical treatment, and aerospace. Studies show that the micro-milling has superiorities such as high efficiency and high flexibility over other methods. Currently, the biggest problem of micro-milling is the influence of burrs on the milling performance, which is an enormous challenge to remove. In the present study, numerical simulations through the finite element method (FEM) and experiments are carried out to optimize cutting parameters of the specimen made of Cr12MoV alloy. Moreover, an improved constitutive model is proposed by considering the size effect of the micro-milling. The proposed model is based on the J-C constitutive model, and it is concluded that the cutting force error is 4.6% through the comparison of experiment and FEM, which further proves the convergence of the improved constitutive model. It is also found that the side burr of HAR slots and the top burr of shallow slots are the biggest factors affecting the surface quality. The depth of cut (DoC) affects the maximum bending angle of the tool, the feed per tooth (FpT) affects the size of the unremoved area, and the spindle speed (SpS) affects the dynamic balance of the micro-mill, through the exploration of the above cutting parameters which can effectively improve the cutting state of the tool and finally achieve the purpose of curbing burr.