Materials Science Forum Vol. 723

Abstract: In this paper, effects of milling parameters on cutting force and surface roughness during symmetrical face dry milling process of super high strength steel 30CrMnSiNi2A were presented. Multiple linear regression model and orthogonal rotary quadratic regression model were established to analyze cutting force and surface roughness, respectively. Their adequacy was estimated by variance analysis and experimental data comparison. Parameters optimization for maximum metal removal rate and minimum surface roughness were also discussed.

Abstract: Ti6Al4V is one kind of difficult-to-machine aeronautical materials, which is generally machined by coated cemented carbide tools. A three-dimensional face milling model is developed in this paper with finite element analysis software AdvantEdge to analyze influences of tool materials on tool temperatures, cutting forces and tool stresses. The simulation results have shown that PCBN tools are the most appropriate for machining titanium alloy when it is machined with heavier cutting parameters. Cemented carbide-K tools and PCD tools are suitable for finish machining titanium alloy. The PCD tools are superior to cemented carbides-K under the same machining conditions. Nature diamond cutting tools are incompatibility to machine titanium alloy due to their higher costs and carbonization at high temperature. In the view of cutting forces and distributions of tool stresses, nature diamond tools are optimal and the cemented carbides-K are the poorest in machinability rate at the same cutting conditions, while super-hard tools gets longer tool life.

Abstract: In this paper, with milling characteristics of high hardness hardened steel, we choice six different coated tools to made cutting experiments on high hardness hardened steel Cr12MoV (HRC65). In this stage, through the analysis of cutting force, cutting temperature, cutting vibration, machined quality and tool wear, we have elected the preferred tool and tool geometry parameters for this processing stage. The results of the study show that: TiAlSiN is the most suitable for Cr12MoV (HRC65), which helps to improve cutting processing productivity, prolong tool life, and enhance processing quality and reduce the processing cost.

Abstract: The experiments of high speed milling Ni-base superalloy GH625 by using two types of the coated cemented carbide tools at home and abroad, using the scanning electron microscopy (SEM) to observe the tools wear morphology, analyzing the worn surface elements distribution by energy spectrum analysis (EDS) and the main wear mechanisms of the tools. The results show that adhesion, oxidation and diffusion are the main wear mechanisms in initiative wearing stage of the domestic coated tools. And the main wear mechanisms of the imported coated tools are adhesion, oxidation, diffusion and coating spallation.

Abstract: In this paper, the effect of cutting parameters on cutting force, cutting temperature and surface roughness on cutting force, cutting temperature and surface roughness are experimentally studied in spray cutting GH4169 Ni-base superalloy used carbide cutting tools. The results showed that reasonable choice of cutting parameters can effective reduction of cutting force and cutting temperature, and improve the machining surface roughness. Thus realizing clean production mode.

Abstract: SiCp/Al composites have been used in a number of engineering applications including the consumer goods. However, the machining of these materials is very difficult because of the abrasive characteristics of the reinforced particulates. In this paper drilling studies on SiCp/Al composites with high volume fraction and large size SiC particles have been conducted by using electroplating diamond drills, and the influences of the cutting speed on the drilling force and surface roughness were investigated.

Abstract: In this paper, the influence of the tool rake angle, cutting depth and cutting speed on exit edge defect sizes are discussed by the two dimension cutting experiment of SiCp/Al composites. The sizes are measured by using the Keyence VHX-1000C type super preview 3D microscopy. The results indicate that exit edge defect sizes are influenced greatly by tool rake angle and cutting depth, and are influenced slightly by the cutting speed. The edge defect sizes have an overall downward trend when the tool rake angle is smaller than 5°, and have an apparent upward trend when the tool rake angle (γ₀) is 10°.The length (L), height (H) of exit edge defects and the negative shear angle increase with increasing of the cutting depth.

Abstract: Nickel-based superalloy is a relatively new class of materials that exhibit high mechanical strength, ductility, creep resistance at high operating temperatures and stress levels. It is widely used in aero engine parts such as blade and blisk. Due to its high hardness and high strength at high temperature, it’s difficult to machine nickel-based alloy. In order to reduce tool wear, trochoidal milling strategy is studied in this paper. With trochoidal tool path strategy, tool load can be reduced and the tool has enough time to be cooled under high cutting temperature. Tool immersion angle in trochoidal milling is smaller than slot milling, thus the tool load can be reduced. Experiment results show that tool flank wear with normal slot milling is about four times larger than that with trochoidal milling. Trochoidal tool path strategy can be further developed for rough milling of compressor blades or rough milling hub of blisks.

Abstract: High speed machining (HSM) is one of the main trends of cutting machinery and is an important development direction of advanced manufacturing technology. In our country, the relevant research of HSM database starts later, especially of the cutting of hardworking material, the actual machining and experiment on the machining technology and the machining parameters of HSM are few, the reasonable machining parameters selection scheme and the appropriate cutter choice method are lack. The paper established HSM database system of the hardworking material based on web to improve cutting efficiency. According to the different feed and cutting tool by the Web form, it gets the rational cutting parameters. And the system determines the tool-path planning by the manufacture HSM of hardworking material processing animation to simulate the high-speed milling. The results of inquiry as a Web page and let you get parameters of optimization, increases efficiency of factories.

Abstract: By combining cutting experiment with finite element method (FEM) simulation, the effect of cutting speed on cutting force, cutting temperature and workpiece surface residual stress has been studied in precision hard turning of hardened steel GCr15 with PCBN. The research results indicate that with rise of cutting speed, cutting force somewhat decreases and periodically changes because of metal softening effect, while cutting temperature increases and its maximum lies near tool tip on the interface of cutting chip and cutting edge, and residual stress largely decreases in a small area under workepiece surface and distributes clearly like a spoon. FEM simulation and experimental results are in good agreement.