Papers by Keyword: Milling Parameters

Abstract: Vertical machining center (VMC) five-axis is advanced metal cutting process which used tomachine advanced materials for creating parts for industries like die, automotive, aerospace, machinerydesign, etc. Input parameters selection very important in VMC-five axis to obtain better surface finishon milled part and enhanced machining economics. In the present work, experimental analysis has beenplanned to study the significances of milling parameters on quality response, surface roughness (Ra) ofD3 steel. The experiments have been planned on D3 steel in VMC five axis as per Box-Behnken designof response surface methodology (RSM). Modeling and optimization have been done by hybrid RSMand Jaya optimization algorithm. The factor effects on Ra has been studied by analysis of signal-tonoise ratio. The concluding remarks has been drawn from the study

Abstract: This study is a kinematic model of a mechanical mill that works with a single ball in motion, and which is operated by a crank and connecting rod system for producing nanocrystalline powders by the process of ball milling. The geometric and dynamic parameters play an important role on the variation of forces created upon impact of the ball with the inside wall of the vial, which caused energy transfer required for the mechanical alloying process. The determination of these forces enables us to know their specific magnitudes on the intensity and milling efficiency, with the advantage of low operating power consumption of the mill and absence of the contamination problem. In addition, we have defined a model for calculating the temperature of the powder trapped between the ball and the wall of the vial of the mechanical mill whose start-up is provided by an electric motor.

Abstract: AlN/Cu composite powder was prepared by ball milling method. Laser particle size analyzer, X-ray diffraction and scanning electron microscopy analysis were performed to study AlN/Cu composite powders. The effects of rotation speed, mixing time, and ball to powder weight ratio (BPR) on the particle size distribution, composition, and morphology were investigated. Results showed that the best ball milling parameters were the rotation speed of 200r/min, mixing time of 6 hours and BPR 10:1. In this best condition, AlN/Cu composite powders would be obtained with optimum particle size distribution and morphology. Then composite powders were pressed at 500MPa and sintered at 1000°C in N₂ atmosphere. Finally, the composite with an AlN content of 33wt% showed the bending strength of 370MPa, Vikers hardness HV154, thermal conductivity of 182.7W/m°C and electrical conductivity of 3.08MS/m. However, the composite with an AlN content of 25wt% showed the bending strength of 329MPa, Vikers hardness HV122, thermal conductivity of 195W/m°C and electrical conductivity of 6.54MS/m.

Abstract: The effect of nickel contents and milling parameters on the preparation procession of TiB₂-Al₂O₃ composite powders during the mechanical alloying (MA) was studied in this paper. Milling parameters have certain influence on the phase transformation of Ni-Al-TiO₂-B₂O₃ system during mechanical processing. With the same milling parameters, the proper content of Ni can promote the reaction route and influence the microtopography of the products.

Abstract: Consider to the properties of Super Alloy GH4169, planning the milling experiment with ceramic cutting tool, which is aimed at studying the milling force of different parameters in each direction based on the software of Labview and KISTLER three-component dynamometer. Then the milling force experience formula was established by MatLab, which offered the theoretic reference to the studies of high speed milling super alloy GH4169 through the analysis and studies of the milling parameters based on the experimental data.

Abstract: Zirconia has been widely concerned in dental restoration duo to its excellent properties, but its high hardness make direct milling inefficient, while pre-sintering zirconia has good machinability. By single factor experiment in high-speed finish milling on 900°C pre-sintering zirconia, effect of four milling process parameters’ change on surface roughness was analyzed, and process sensitivity and relative sensitivity were put forward to compare the effect degree and to optimize milling parameters’ domains respectively. Roughness models are established on each parameter, and analysis results show the effect degree in order of spindle speed, feed engagement, cutting width, and cutting depth, spindle speed in them is a main factor. Based on relative sensitivity, milling parameters stability domain and instability domain are presented.

Abstract: In order to control surface residual stress in milling aviation stainless steel, orthogonal experiments were conducted to investigate the effects of milling parameters on surface residual stress in milling of 1Cr11Ni2W2MoV. The empirical formula of surface residual stress was established to analyze the sensitivity of surface residual stress on milling parameters. The milling parameters stability region and instability region were acquired. Using the extreme difference analysis method, the optimum selection of the milling parameters interval was proceeded. The results show that residual stress along X direction is most sensitive to the feed per tooth, residual stress along Y direction is most sensitive to the milling speed. The optimum milling speed ranges from 25m/min to 40m/min, the optimum milling depth ranges from 0.4mm to 0.45mm, and the optimum feed per tooth ranges from 0.06 mm/z to 0.08mm/z, surface residual stress can be effectively controlled.

Abstract: Ultra-high strength steel 30Cr3SiNiMoVA has excellent mechanical properties, including high strength and hardness, a certain degree of ductility and toughness. The superior properties have awarded a wide application of 30Cr3SiNiMoVA in the aviation industry. But on the other hand, The ultra-high strength steel 30Cr3SiNiMoVA is a typically difficult-to-cut material, The difficult-to-cut features in the process of which include high cutting temperature and cutting force, severe tool wear, low productivity and so on. So selection of appropriate cutting parameters is very important in the process. In this paper, high-speed milling tests were carried out, to investigate the performance of 30Cr3SiNiMoVA under given conditions. Basing on the results of the experiments, Empirical formulas of surface roughness and cutting force were got. Finally, the multi-objective optimization on cutting parameters was conducted. The optimized parameters in the test conditions were a_p=10mm, V=50/min, fz=0.06mm/z, a_w=0.4mm.

Abstract: The orthogonal experiments of end milling were designed. Workpiece surfaces hardening were studied in high-speed milling. The results indicate that the degree of surface work-hardening in high-speed milling 8407 mold-steel is lower than that in conventional speed milling;By choosing the appropriate cutting parameters, to improve the surface quality of the workpieces and the processing efficiency is beneficial;Through changing the high-speed milling parameters to control the work hardening, the effect is not so obvious.

Abstract: This research was to study the effect of face milling on the surface finish of stainless steel: AISI 304. The experiment was applied on three factors and were consisted of three levels of cutting speed, depth of cut and feed rate. The face milling process was chosen to experiment which used face milling cutter with insert carbide tool. The surface roughness average (Ra) was applied to indicating for surface finish. The experiment results were analyzed by ANOVA. The main factors and factors interaction that affected to surface finish were investigated. Effect of cutting speed, feed rate and depth of cut on surface finish of stainless steel: AISI 304 was discussed.