Experimental Study Of Friction On The Tool-Chip Contact Field In Metal Cutting Process

It is important to describe friction conditions at the tool and chip contact area in machining, since it affect many variables such as plastic deformation of the metal. With an accurate model of the friction conditions it is also possible to determine cutting force, temperature distribution, chip formation more efficiently. Knowledge of the friction conditions at the tool and chip contact area is extremely important for achieving accurate machined work surface. There has been a significant meaning for investigating the friction conditions at the tool and chip contact area.For the friction conditions at the tool-chip contact in the metal cutting process, the author chooses high-speed steel as the tool material and C35 steel as the work piece material was studied and analyzed in this paper.Firstly, the author makes some normal shape tools and conducts cutting experiment, uses SEM,surface roughness apparatus and micro hardness measuring device to investigate and measure the parameter of tool face at different area after cutting. The result shows that microstructure, surface shape and micro hardness are found to be able to reflect the friction state at different area.In order to obtain the different friction distortion chip through different friction area, the author designed a series of experiment tools, which have different tool face in length. Used the tools, have carried out several groups cutting experiment, obtained different chips and measured cutting force at the same time. To observe and measure the surface shape,micro hardness and surface microstructure of the chip, calculated the tool-chip friction in the cutting process and make contrast with the surface shape,micro hardness and surface microstructure of the tool face, according to the similar changes of the three character on the tool face and chip surface, it can reflect the tool-chip friction state at different area.Based on experiments, a new partitioned method of the tool-chip friction area for high-speed steel cutting C35 steel is proposed. Based on the method, the tool and chip contact area have been plotted three areas:â… area(near the cutting edge) andâ…¡area(adjacent toâ… )can be distinguished accurately through microstructure image of the tool and surface profile curve;â…¡area andâ…¢area(apart from the tool edge ) can be distinguished by compared the real measured friction with the theoretical calculated friction.