Experimental study on flexible fiber assisted stress rheological passivation and polishing of complex edge of cemented carbide insert

Abstract

To obtain the high consistency passivation of cutting edge of the cemented carbide insert with complex shape and improve the tool performance and life, the flexible fiber assisted stress rheological polishing method, which utilizes the rheological properties of non-Newtonian fluid under shear stress and the flow control effect of flexible fibers, was proposed to polish the complex shape edge of cemented carbide insert. The deviation value K of the passivation radius of the cutting edge was used as the evaluation index, and Taguchi method was employed to analyze the effects of the polishing speed, the fiber density and the fiber-insert contact length on the edge passivation radius and its consistency. The weight of each factor was evaluated by variance analysis method, and the optimal process parameters were obtained by combining the influence of the polishing parameters on the cutting edge at different positions. The optimal combination of process parameters is that the fiber density is 200 to 250 fibers/cm2, the contact length is 4 mm and the polishing speed is 55 r/min. Under the optimal combination of process parameters, the passivation radius of seven cutting edges can reach (50.0 ± 5.0) μm after polishing for 10 min, the surface roughness Ra of the cutting edges are reduced from (118.00 ± 10.00) nm to (9.35 ± 0.75) nm and the cutting edge is complete and free of defects.

Keywords

• stress rheological polishing
• cemented carbide insert
• complex blade shape
• edge passivation
• consistency