Research On Cutting The Iron-based Superalloy With The Coated Carbide Tools

Iron-based superalloy has the property of great fabricability, good ductibility, poor heat conductivity, serious hardening and so on. In the process of cutting, it shows some severe problems, such as high cutting temperature, big distortion of ductility, big cutting force and serious wear for cutting tools. Thus, it belongs to typical materials difficult to cut. The coated carbide tools, which have high hardness and good wear performance, were used in the paper. Besides, they were also studied for cutting the iron-based superalloy from the aspects of cutting force, degree of coarseness on the surface, wear for cutting tools and chips formFirst, this paper researched the influences of cutting parameter and cutting tools rake angle for cutting force through the orthogonal test. The experimental results showed that the cutting depth had the greatest influence on the cutting force, which changed in proportion. The second biggest effect was the feed. Cutting speed influenced the results least. Main cutting force Fz was bigger than feeding force Fx and cutting depth of resistance force Fy. which was the least, Besides, through comparing the experimental results, the article found that working rake angle had the greatest effects on the cutting force. Under the process by using the negative working rake angle, both main cutting force and unit cutting force were bigger. Thus, this paper suggests that workers should use positive working rake angle to cut and process iron-based superalloy.Second, this paper studied the influences of cutting parameter for the degree of surface roughness through orthogonal test. Through the observation and variance analysis method, feedingfhad the maximum influences on the degree of GH2132surface roughness, and the cutting speed was the second greatest effect. The influences of cutting depth were not significant. The range analysis showed that the preferred process conditions of surface roughness was when the cutting depth was0.1mm, feeding was0.1mm/r and cutting speed was66m/min. What’s more, this paper also obtained the empirical model of cutting force and degree of surface roughness by using regression analysis.Third, this research also studied the wear of cutting tools. In the cutting process of iron-based superalloy, cutting speed had great influences on the life of cutting tools. When the cutting speed increased, the wear of coated carbide tools increased and the life of the tools decreased. The wear forms of coated carbide tools were mainly crescent and groove wear. The layers of some areas dropped. When the cutting speed kept on increasing, both the coated carbide tools and ceramic cutting tools were broken. What’s more, the broken forms were breakage and flaking. The main reason for wear of coated carbide tools was adhesive wear, together with mechanical wear, oxidation wear and diffusion wear. This paper suggests that it is better to choose layer with good chemical stability when iron-based superalloy is processed.Forth, this research analyzed the macroscopic and micro morphology of chips. Through the research we found that chip breaker had great influence on how the chips got out, and then played an important role on improving the quality of surface and decreasing the wear of cutting tools. When ceramic cutting tools cut materials, chips showed all kinds of colours, reflecting that ceramic cutting tools had very high cutting temperature during the process. Besides, when coated carbide tools cutting materials, cutting speed had great influences on the micro morphology of chips. If the cutting speed increased to enough degree, the chips would become zigzag. The main reason for this phenomenon was adiabatic shear.At last, through comparing the results of experiment, the main cutting force, cutting resultant of forces, and unit cutting force were all less than ceramic FD22cutting tools, which showed better cutting property. At the same time, ceramic cutting tools lost efficacy soon because the cutting tools were broken and the surface dropped off. However, the life of coated carbide tools were longer and those tools had better anti-force capability. Therefore, coated carbide tools were a better choice than the ceramic cutting tools in this experiment to process iron-based superalloy.