Papers by Keyword: High Speed Machining

Abstract: The finite element-based machining simulations for evaluation/computation of different machining responses (i.e., cutting temperature, tool wear, cutting force, and power/energy consumption) are investigated by number of researchers. In this work, finite element machining simulation was performed to obtain knowledge about cutting forces during machining of hard materials. Titanium alloy (Ti-6Al-4V) has been increasingly used in aerospace and biomedical applications due to high toughness and good corrosion resistance. The high speed machining (HSM) simulation of Ti-6Al-4V work-piece using carbide tool coated with TiCN has been conducted with different combination of cutting conditions for prediction of main cutting force (Fz). The simulated result obtained from Deform 3D software is validated with experimental result and it was found that the result found in good agreement. The parametric variation shows that depth of cut and feed are influencing parameters on cutting force.

Abstract: With the development of high-speed machining technology, new technical requirements have been put forward for the clamping of high-speed cutting tools. The traditional clamping methods can not meet the needs of high-speed machining. In this paper, the comprehensive performance of high-speed chucks is systematically compared and analyzed, and the characteristics and main application areas of various high-speed chucks are sorted out, which provides a theoretical basis for scientific and rational selection of chucks.

Abstract: Machining of titanium alloys poses a serious challenge for the industry, due to its tendency to work harden during the machining process, high cutting temperatures, high cutting pressures, chatter, and its reactivity with tool materials over 500°C. In conjunction with its low thermal conductivity and low modulus of elasticity, these factors impede the machinability of titanium. This work presents an overview on machining the Titanium Alloy by considering the energy involved in the manufacturing processes in order to have a low carbon manufacturing requirements by evaluating carbon emission in the manufacturing process plan.

Abstract: The energy consumption and machinability index of metallic alloys are very important in determining the economic and environmental value of manufacturing process. Various machinability problems with Nitronic 33 steel alloy have been reported in literature. These problems have been attributed to the work hardening of the material during machining operation and hence greatly influences and contributes to the green house gas emission. In this work, the chip and burr formation during the machining of Nitronic 33 steel alloy was investigated in other to optimize the cutting parameters and provide a knowledge base for machinists when machining austenitic stainless steels. The result shows that although continuous chips were formed throughout the machining tests, an evidence of continuous chip with built-up edges was also observed. This phenomenon tends to initiate the formation of discontinuous chips especially at high pressure coolant flow of 7 and 9.7 MPa. It is concluded that conventional cutting environment at 90 m/min cutting velocity is the optimum process parameter most suitable for machining Nitronic 33 steel alloy. The research outcome will address some of the problems encountered during high speed machining of Nitronic 33 steel alloy and the general understanding of the machinability of this alloy.

Abstract: Hardened AISI 1045 steel implemented in machine tool spindle was previously ground using grinding operation. This research aims to address the feasibility of hard turning AISI 1045 using PCBN tool with chip breaker under dry condition. Chip morphology, cutting force and temperature were measured, analyzed and correlated with machining parameters. Experimental results demonstrate that serrated chips are generated at high speeds, high feed rate is an assistant to promote serrated chips, and chip breaker can help break chip into acceptable lengths. Cutting forces were characterized with periodic fluctuation along three directions as chips are serrated. Temperature at machined zone can reach as high as 1200^°C, which indicates that adiabatic shear bands can be successfully achieved during the machining of hardened AISI 1045 steel without applying lubricants.

Abstract: Serrated chips were a universal phenomenon and it had a significant effect on cutting process. In this paper, single tooth dry cutting of TC11 titanium alloy were conducted on a five-axis CNC machine using Stellram milling cutter with a diameter of 32 mm. Both chip macroscopic morphology and microcosmic morphology of TC11 titanium alloy were studied in-depth examining the impact of cutting speed and feed rate to the serrated chips. The results showed that: with the increase of cutting speed, the chip morphology of titanium alloy TC4 experienced a change process from the hair bar to a “C” shape and then become a long strip. The critical cutting speed of TC11 for serrated chips was found at 80 m/min and the critical feed rate to form serrated chip was defined as 0.05mm/z. With the increasing of cutting speed, the extent of chip serration was significantly enhanced. Increasing cutting speed can decrease the feed rate to form serrated chips.

Abstract: Results of modeling rheological properties (constitutive models) of composite material Victrex PEEK 90HMF20 by reversible analysis method at high-speed milling considering the direction of the reinforcing fiber are presented. Strain hardening until the moment of rupture was determined by the results of static tests of destruction at different temperatures. Coefficients of viscoplastic hardening and thermal softening were determined by the results of statistical processing of experimental milling samples of PEEK-based deformation velocity field obtained by simulation of the process of edge cutting machining in Deform 2D.

Abstract: High efficiency and high speed are the development directions of modern manufacturing technologies. In the last two decades, high speed machining is successfully applied in cutting steel and alumina alloy, due to its unique advantages. However, it is not yet prevalent in powder metallurgy (PM) superalloy machining. This work focuses on the shear angles and influencing rules in high speed machining PM nickel based superalloy, in order to provide reliable theoretical and practical methods in high efficiency/speed machining this kind of material in production practice.

Abstract: Finite element simulation of high speed machining of Ti6Al4V alloy was carried out based on the software of Abaqus. The Johnson-Cook constitutive model was chosen for the material of Ti6Al4V, the parameters of the model were obtained through the SHPB (Split Hopkinson Pressure Bar) experiment. The similarity of the chips obtained from the simulation and that obtained from the experiment indicated that the parameters of the Johnson-Cook constitutive model for Ti6Al4V alloy were reliable. Different cutting parameters and different tool geometric parameters were used in the simulations to find out their effects to the simulation results. Also a comparison was made between the results got form the simulations results and the experimental results, a good agreement between them indicated that the finite element simulation of high speed machining of Ti6Al4V is reliable, so it can be concluded that the finite element simulations of high speed machining can be widely used in practice to study the more about the machining process and reduce the experimental expenses.

Abstract: High-speed chuck is an important component of high speed machining tooling system. Its properties directly affect the performance and processing quality of advanced numerical control machine. Using the finite element method, the research analyzed influence of inertial centrifugal force caused by unbalance on the dynamic characteristics of HSK hydraulic clamping chuck tooling system and systematically revealed variation of shank, chuck and blade point displacement. It is found that blade point, as well as chuck and shank displacement response amplitude of tooling system rises as a whole with the increase of excitation frequency; the dynamic displacement response increment shows linear growth with unbalance amount, which provides a theoretical basis for optimum design and balancing control of HSK hydraulic chunk tooling system.