Effect of Increasing Spindle Speed at a Constant Chip Load on Cutting Force Behaviour of Hastelloy X

Author(s):  
Nor Aznan Mohd Nor ◽  
BT Hang Tuah Baharudin ◽  
Jaharah A Ghani ◽  
Mohd Khairol Anuar Mohd Ariffin ◽  
Zulkiflle Leman ◽  
...  

Cutting force is vital in machining nickel-based superalloys due to their excellent mechanical properties, thus creating difficulty in cutting. In the current scenario of metal machining, milling processes require high spindle speed and low chip load, which result in a low cutting force. However, low chip load not only result in low cutting force but also result in a low material removal rate (MRR). It is contrary to the ultimate high-speed machining (HSM) goal, which is to improve productivity and cost-effectiveness. Therefore, the emergence of an approach for achieving simultaneous low cutting force and high MRR is crucial. This paper presents the effect of increasing spindle speed at a constant chip load on the cutting force of Hastelloy X during half-immersion up-milling and half-immersion down-milling. In both half-immersions, the simulation results and experimental results are in good agreement. The percentage contribution of feed force, normal force and axial force to the resultant force can be arranged descendingly from high to low as axial force > normal force > axial force. Moreover, feed force, normal force, axial force and resultant force have a U-shaped behaviour. The spindle speed of 24,100 rpm and a chip load of 0.019 mm/tooth were found to achieve both low cutting force and high MRR.

2020 ◽  
Vol 14 (1) ◽  
pp. 6497-6503
Author(s):  
Nor Aznan Mohd Nor ◽  
B. T. H. T. Baharudin ◽  
J. A. Ghani ◽  
Z. Leman ◽  
M. K. A. Ariffin

Research on cutting force revealed that the cutting force decreases as cutting speed increases, which is in line with Salomon’s Theory. However, the fundamental behaviour was never clearly explained because most studies had focused on increasing the cutting speed by increasing spindle speed without retaining the rate of chip load. On that note, the effect of increasing spindle speed while chip load is constant on the cutting force of Hastelloy X is presented in this paper. Third Wave AdvantEdge software was applied and half-immersion up-milling simulations were conducted in dry condition. Result showed that the resultant force was primarily affected by the axial force, followed by normal force and feed force. Trend-lines indicated that the behaviour of cutting force components and resultant force was quadratic. Desirability Function Analysis (DFA) results revealed that the optimum combination of chip load and spindle speed led to lowest cutting force components and resultant force was at 0.013 mm/tooth and 24,100 RPM. Furthermore, the optimum cutting conditions that led to the lowest cutting force components and resultant force at chip loads of 0.016 mm/tooth and 0.019 mm/tooth was 24,100 RPM also. Therefore, increasing Material Removal Rate (MRR) while minimizing cutting force components and resultant force can be achieved by increasing the amount of chip load at spindle speed of 24,100 RPM.


2015 ◽  
Vol 1115 ◽  
pp. 12-15
Author(s):  
Nur Atiqah ◽  
Mohammad Yeakub Ali ◽  
Abdul Rahman Mohamed ◽  
Md. Sazzad Hossein Chowdhury

Micro end milling is one of the most important micromachining process and widely used for producing miniaturized components with high accuracy and surface finish. This paper present the influence of three micro end milling process parameters; spindle speed, feed rate, and depth of cut on surface roughness (Ra) and material removal rate (MRR). The machining was performed using multi-process micro machine tools (DT-110 Mikrotools Inc., Singapore) with poly methyl methacrylate (PMMA) as the workpiece and tungsten carbide as its tool. To develop the mathematical model for the responses in high speed micro end milling machining, Taguchi design has been used to design the experiment by using the orthogonal array of three levels L18 (21×37). The developed models were used for multiple response optimizations by desirability function approach to obtain minimum Ra and maximum MRR. The optimized values of Ra and MRR were 128.24 nm, and 0.0463 mg/min, respectively obtained at spindle speed of 30000 rpm, feed rate of 2.65 mm/min, and depth of cut of 40 μm. The analysis of variance revealed that spindle speeds are the most influential parameters on Ra. The optimization of MRR is mostly influence by feed rate. Keywords:Micromilling,surfaceroughness,MRR,PMMA


2015 ◽  
Vol 787 ◽  
pp. 664-668 ◽  
Author(s):  
K. Anand ◽  
M.V. Siddharth ◽  
K.S. Vijay Sekar ◽  
S. Suresh Kumar

Composite materials are in-homogenous, anisotropic and cause high tool wear at high cutting speeds in machining. Industrial practices worldwide reveal a need to use high speed machining to achieve the desired material removal rate, surface finish and to reduce cost cutting. In this research work, impact of turning glass fibre reinforced polymer tube with two contrasting turning tool inserts such as titanium aluminium nitride and tungsten carbide have been analysed. The turning was conducted at low to high cutting conditions up to spindle speeds of 2000 rpm and feed rate of 0.446mm/rev. The cutting force, feed force were acquired with a strain gauge based dynamometer, the chip cross section was observed using scanning electron microscopy and the temperature was sensed with a infra red thermo sensor. The advanced titanium aluminium nitride insert shows better machining characteristics across cutting speeds.


2014 ◽  
Vol 564 ◽  
pp. 475-480
Author(s):  
M.F.C. Ibrahim ◽  
B.T. Hang Tuah bin Baharudin ◽  
Naain Shari

Stavax Supreme material is classified as difficult-to-machine material. The difficulty does not preclude the use of this material, especially in the mold industry. In this experiment, high speed end milling of Stavax Supreme (52 HRC) was investigated using five different types of tool. Performance of the cutting tools was compared with respect to tool life and surface roughness of the workpiece. Machining process was conducted in two parameters where each parameter used different rotation spindle speed and feed rate but same chip per tooth removal rate. The best cutting performance was obtained with TiN and TiCN. TiAlN tool also proved to be suitable for high speed end milling of Stavax Supreme but for finishing process only because fast tool wear in high spindle speed. The Xceed coated tool is more suitable for roughing process only in high spindle speed.


2010 ◽  
Vol 447-448 ◽  
pp. 268-271 ◽  
Author(s):  
Yuna Yahagi ◽  
Tomohiro Koyano ◽  
Masanori Kunieda ◽  
Xiao Dong Yang

This paper describes machining characteristics of high spindle speed WEDG using the electrostatic induction feeding method. In this method, non-contact electric feeding allows the workpiece rod to be rotated at a high speed of up to 50000rpm. Since the temperature rise on the workpiece surface is low, the material removal rate was two times higher and the surface roughness was also improved compared to the normal RC discharge circuit where the rotational speed was 1000rpm at the highest due to contact electric feeding using a brush. Furthermore, micro rods thus prepared were used as tool electrodes to machine micro-holes with the same rotation speed of 50000rpm. It was found that smaller gaps and better straightness can be obtained due to the high flushing efficiency at the high spindle speed.


Author(s):  
Mohammad H. Kurdi ◽  
Tony L. Schmitz ◽  
Raphael T. Haftka ◽  
Brian P. Mann

High-speed milling provides an efficient method for accurate discrete part fabrication. However, successful implementation requires the selection of appropriate operating parameters. Balancing the multiple process requirements, including high material removal rate, maximum part accuracy, sufficient tool life, chatter avoidance, and adequate surface finish, to arrive at an optimum solution is difficult without the aid of an optimization framework. In this paper an initial effort is made to apply analytical tools to the selection of optimum cutting parameters (spindle speed and depth of cut are considered at this stage). Two objectives are addressed simultaneously, maximum removal rate and minimum surface location error. The Time Finite Element Analysis method is used in the optimization algorithm. Sensitivity of the surface location error to small changes in spindle speed near tooth passing frequencies that are integer fractions of the system’s natural frequency corresponding to the most flexible mode is calculated. Results of the optimization algorithm are verified by experiment.


2011 ◽  
Vol 314-316 ◽  
pp. 1788-1791 ◽  
Author(s):  
Feng Yun Yu ◽  
Ming Jun Feng ◽  
Ming Jun Dai ◽  
Hong Jiang Sun

High-speed cutting technology is widely used in aviation, mold, automotive industries and other fields for its high machining efficiency, smaller cutting force, less cutting heat and high machining precision. However, the production site in China, high-speed machine tools do not really play its role in some enterprises, without real sense of the high-speed machining. Aluminum alloy 2A70 as the research object, using single-factor test, study the effect law of high-speed milling parameters on milling force here. The results show that: the cutting force is varying for high-speed milling, showing a periodic variation, with the transient characteristic, the milling force is large amplitude fluctuations in X and Y direction, the amount of change is respectively 55.544N and 56.306N. Milling force influenced by the spindle speed, with the increase of spindle speed, X contribute to the greatest change in the direction of milling, Y direction second, Z direction is almost unchanged. Under the experimental conditions, the stability high-speed cutting area of 2A70 is the spindle speed in the area of 21000rpm~27000rpm. The results of high-speed milling of aluminum alloy have certain significance.


Author(s):  
Kundan K. Singh ◽  
V. Kartik ◽  
Ramesh Singh

Miniature components with complex shape can be created by micromilling with high surface accuracy. However, for difficult-to-machine materials, such as Ti-alloys, failure of low flexural stiffness micro-tools is a big limitation. High spindle speeds (20,000 to 100,000 rpm) can be used to reduce the undeformed chip thickness and the cutting forces and hence the catastrophic failure of the tool can be avoided. This reduced uncut chip thicknesses, in some cases lower than the cutting edge radius, can result in intermittent chip formation which can lead to dynamic variation in cutting forces. These dynamic force variations coupled with low flexural rigidity of micro end mill can render the process unstable. Consequently, accurate prediction of forces and stability is essential in high-speed micromilling. Most of the previous studies reported in the literature use constant cutting coefficients in the mechanistic cutting force model which does not yield accurate results. Recent work has shown significant improvement in the prediction of cutting forces with velocity-chip load dependent coefficients but a single function velocity-chip model fails to predict the forces accurately at very high speeds (>80,000 rpm). This inaccurate force prediction affects the predicted stability boundary at those speeds. Hence, this paper presents a segmented approach wherein a function is fit for a given range of speed to determine the chip load dependent cutting coefficients. The segmented velocity-chip load cutting coefficient improves the cutting force prediction at high speeds. R2 value is found to be improved significantly (>90% for tangential cutting coefficient) which yields the better forces prediction and hence more accurate stability boundary. This paper employs two degrees of freedom (2-DOF) model with forcing functions based on segmented velocity-chip load dependent cutting coefficients. Stability lobe diagram based on 2-DOF model has been created for different speed ranges using Nyquist stability criteria. Chatter frequency ranges between 1.003 to 1.15 times the experimentally determined first modal frequency. Chatter onset has been identified via a laser displacement sensor to experimentally validate the predicted stability lobe.


2017 ◽  
Vol 9 (7) ◽  
pp. 168781401771662 ◽  
Author(s):  
Changfeng Yao ◽  
Zheng Zhou ◽  
Jiyin Zhang ◽  
Daoxia Wu ◽  
Liang Tan

In the process of face-turning high-temperature alloy Inconel718 with carbide tools and ceramic tools, the change rules of cutting force were studied and the empirical models of cutting force on the cutting parameters were established. For the tools, the main cutting force has positive relation to both the feed rate and the turning depth. Variation trends of the axial force are in accordance with the increase in these two parameters. During the increasing process of the cutting speed, the feed force changes slightly while the main cutting force decreased about 96 N when using the carbide cutter. For the ceramic cutter, the main cutting force and the axial force increased to about 380 N first and then decreased when the cutting speed increased. The axial force affected not only the processing parameters but also the geometrical parameters of the cutter. There exist some relationships between component forces.


2012 ◽  
Vol 134 (7) ◽  
Author(s):  
Thomas P. James ◽  
John J. Pearlman ◽  
Anil Saigal

A new analytical model to predict bone sawing forces is presented. Development of the model was based on the concept of a single tooth sawing at a depth of cut less than the cutting edge radius. A variable friction model was incorporated as well as elastic Hertzian contact stress to determine a lower bound for the integration limits. A new high speed linear apparatus was developed to simulate cutting edge speeds encountered with sagittal and reciprocating bone saws. Orthogonal cutting experiments in bovine cortical bone were conducted for comparison to the model. A design of the experiment’s approach was utilized with linear cutting speeds between 2600 and 6200 mm/s for depths of cut between 2.5 and 10 μm. Resultant forces from the design of experiments were in the range of 8 to 11 N, with higher forces at greater depths of cut. Model predictions for resultant force magnitude were generally within one standard deviation of the measured force. However, the model consistently predicted a thrust to cutting force ratio that was greater than measured. Consequently, resultant force angles predicted by the model were generally 20 deg higher than calculated from experimental thrust and cutting force measurements.


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