The simulation and experimentation of spiral flat bottom engraving

The study uses rigid-plastic finite element (FE) DEFORM TM 3D software to investigate the plastic deformation behaviour of spiral flat bottom engraving. The finite element analysis assumes that the spiral flat bottom is a rigid body. During the engraving process, the deformation causes an increase in temperature and wear inside the blank. The FE analyses investigate the effects of cutting speed, depth of cut, and the feed of the workpiece on the damage, effective strain, stress, temperature, and wear induced within the workpiece. The simulation results confirm the suitability of the DEFORM TM 3D software for modelling the spiral flat bottom engraving. Comparisons of engraving of spiral flat bottom with clockwise and counter-clockwise have been performed. The analysis of following stress-strain simulation has been predicted by machine learning in this study. Eventually, the experiment of spiral flat bottom engraving is used.


Introduction
The current development of new materials and alloys [1] was getting widely.You et al. [2] explored the experiment of accelerating the life of milling cutter.A tool wear area was proposed to detect tool wear.Aderhold et.al. [3] experimental results presented showed that tool wear begins with smooth wear.Balaganesan et al. [4] studied the effect of cutting edge radius on end milling.Savas et al. [5] reported that cutting temperature and cutting force are the two main parameters affecting machining finishing quality and tool life.On the other hand, Kiswanto et al. [6] studied the characteristics of the burr formation and the performance of cutting parameters at spindle speed (n, rpm) and feed rate (f, mm/s) in three machining time (t, min) intervals, by using a small micro-milling machine.During micro-milling, the formation of burrs greatly affects workpiece quality, since the size of the burrs can approach the size of the tool diameter.Auric et al. [7] developed a basic model of burr formation.It included the effect of material properties on orthogonal cuts.Finite element method analysis used to understand and predict the burr formation.Wang et al. [8] studied the relationship between stress triaxiality and chip formation process, based on the finite element method.Wan et al. [9] investigated a theoretical approach to predict micromilling forces by incorporating the effect of tool deflection on the process.The 3D vibration-assisted milling model developed by considering the theory of orthogonal helical and multi-body kinematics [10].The cutting force component depended on the geometry of the cutting edge and the grip conditions [11].Cui et al. [12] studied the experiments of orthogonal cutting under different cutting parameters were carried out.Kumar et al. [13] presented the establishment of a method to control the severe sliding contact.Wang et al. [14] focused on the cutting speed increase, the greater compressive residual stresses were developed deeper below the surface.Therefore, the purpose of the study is to investigate into the difference between clockwise and counter-clockwise engraving of spiral flat bottom.

Theoretical background 2.1. The plastic flow stress of finite element simulation
The basic theory of finite element simulation for material deformation is described.The plastic flow stress of a material depends on the strain state, strain rate, and temperature and can be calculated as a function of Eq. ( 1) where σ is the effective stress, ε is the effective plastic strain, ε is the effective strain rate, and T is the current temperature.

Machine learning function
The research machine learning function uses stochastic gradient descent method.Stochastic gradient descent is an iterative method for optimizing an objective function.Regularization is a way to turn a complex model into a simple.The stochastic gradient descent equation shown in Eq. ( 2) is as below: where  is the learning rate.Learning rates above 0.025 will cause the training to converge erratically.

Materials and methods
In this study, a spiral flat bottom engraver was used as the cutting tool.The engraving parameters of spiral flat bottom are shown in the Table 1. Figure 1 describes the size of spiral flat bottom engraving, the cutter length was 36mm, the diameter was 3.175mm, and the blade angle was 60 degrees.Figure 2 illustrates the front view of the spiral flat bottom engraving.Figure 3 shows the top view of the spiral flat bottom engraving.Spiral flat-bottom engraving has high hardness, high wear resistance, and long tool life.Its processing materials are aluminium, copper, and other precision parts processing.

Results and discussion
The simulation adopts the DEFORM TM finite element software.Figure 4 describes the simulation of the spiral flat bottom engraving.The feed rate is 0.1 mm/s and the rotational speed is 10,000 rpm. Figure 4(a) illustrates counter clockwise feed of engraving.Figure 4(b) describes clockwise feed of engraving.Figure 5 illustrates the simulation of the after engraving.Figure 5(a) shows counter clockwise feed of engraving.Figure 5(b) describes clockwise feed of engraving.Figure 6 describes the simulation of the after engraving.Figure 6(a) illustrates the simulation counter-clockwise feed of engraving.Figure 6(b) describes the simulation clockwise feed of engraving.The elements are stressed and extruded resulting in different sizes.The main purpose was to analyse the difference of the cutter in different tool steering.Figure 7 illustrates the aluminium of the after engraving.Figure 7(a) shows the front view of aluminium.Figure 8 shows the effective stress analysis of the workpiece.The maximum effective stress is used as the benchmark for comparison in this research data.Figure 8(a) describes effective stress of counter clockwise feed.The maximum effective stress was at the cutting part of the blade.The maximum effective stress is 1520 MPa. Figure 8(b) illustrates the effective stress of clockwise feed.The maximum effective stress is that position where the tool back rubs against the workpiece.The maximum effective stress is 1340 MPa. Figure 9 describes the state variable analysis of the effective stress.Figure 9(a) illustrating the counter-clockwise feed engraving has a stable waveform in the effective stress.Figure 9(b) illustrates the state variable analysis of the effective stress that clockwise feed of engraving.The effective stress produces extrusion at around 3.5 seconds, resulting in rough cutting.It can be seen from the figure that the stress generated by clockwise cutting is relatively large, and the tool resistance will also increase relatively.Figure 10 describes the stochastic gradient descent method of the effective stress.Figure 11 describes the effective strain analysis of the workpiece.Figure 11(a) illustrates effective strain of counter clockwise feed.The effective strain was evenly distributed in the workpiece.The maximum effective strain is 104 mm/mm.Figure 11(b) illustrates effective strain of clockwise feed.The maximum effective strain is evenly distributed in the workpiece.The maximum effective strain is 347 mm/mm.Figure 12 describes the state variable analysis of the effective strain.Figure 12(a) shows the state variable analysis counter clockwise feed.The effective strain rises upwards with time.Figure 12(b) describes the state variable analysis the clockwise feed.The effective strain rises upwards with time.Figure 13 illustrates the stochastic gradient descent method of the effective strain.Figure 13(a) describing the predicted curve of effective stress goes down smoothly.

Conclusions
The purpose of the study aims at exploring the difference between clockwise and counter-clockwise engraving of spiral flat bottom.The main findings of this study are follows: The maximum effective stress is at the cutting part of the blade.The counter clockwise feed of engraving makes the effective stress have a stable oscillatory waveform.The clockwise feed of engraving makes the effective stress produce the extrusion at around 3.5 seconds, resulting in rough cutting.It notes that the stress generated by clockwise cutting is relatively large, and the tool resistance increases relatively.The predicted curve of effective stress goes down smoothly.The maximum temperature is on the cutting part of the blade.The maximum temperature is 99.1 o C. The temperature curve illustrates fluctuations of different sizes, and the predicted curve of temperature goes up smoothly.The maximum wear depth with counter clockwise feed is 0.0609 mm.The clockwise cutting produces greater wear.The location of tool wear is consistent with the simulation analysis.In general, the combination of engraving and machine learning has great application prospects, which can optimize the production process, improve production efficiency and product quality.However, achieving this combination of technologies still needs to solve many problems encountered in technologies and practical applications.This paper hopes to stimulate more extensive and in-depth researches and practice through comprehensive analysis so as to promote better combined application of engraving and machine learning.

Figure 3 .
Figure 3.The top view of the spiral flat bottom engraving.

Figure 7 (Figure 4 .Figure 5 .Figure 6 .
b) describes the top view of the aluminium.The main purpose is to analyse the difference of the cutter in different tool steering.The simulation of the before engraving: (a) counter-clockwise feed, (b) clockwise feed.The simulation of the after engraving: (a) counter-clockwise feed, (b) clockwise feed.The simulation of the after engraving:(a) counter-clockwise feed, (b) clockwise feed.

Figure 10 (Figure 8 .Figure 9 .
Figure8shows the effective stress analysis of the workpiece.The maximum effective stress is used as the benchmark for comparison in this research data.Figure8(a) describes effective stress of counter clockwise feed.The maximum effective stress was at the cutting part of the blade.The maximum effective stress is 1520 MPa.Figure8(b) illustrates the effective stress of clockwise feed.The maximum effective stress is that position where the tool back rubs against the workpiece.The maximum effective stress is 1340 MPa.Figure9describes the state variable analysis of the effective stress.Figure9(a) illustrating the counter-clockwise feed engraving has a stable waveform in the effective stress.Figure9(b) illustrates the state variable analysis of the effective stress that clockwise feed of engraving.The effective stress produces extrusion at around 3.5 seconds, resulting in rough cutting.It can be seen from the figure that the stress generated by clockwise cutting is relatively large, and the tool resistance will also increase relatively.Figure10describes the stochastic gradient descent method of the effective stress.Figure 10(a) representing the predicted curve of effective stress goes down smoothly.Figure 10(b) representing the predicted curve of effective stress goes down smoothly.

Figure 11 .Figure 13 .
Figure11describes the effective strain analysis of the workpiece.Figure11(a) illustrates effective strain of counter clockwise feed.The effective strain was evenly distributed in the workpiece.The maximum effective strain is 104 mm/mm.Figure11(b) illustrates effective strain of clockwise feed.The maximum effective strain is evenly distributed in the workpiece.The maximum effective strain is 347 mm/mm.Figure12describes the state variable analysis of the effective strain.Figure12(a)shows the state variable analysis counter clockwise feed.The effective strain rises upwards with time.Figure12(b)describes the state variable analysis the clockwise feed.The effective strain rises upwards with time.Figure13illustrates the stochastic gradient descent method of the effective strain.Figure13(a) describing the predicted curve of effective stress goes down smoothly.Figure13(b) represents the predicted curve of effective stress goes down smoothly.High equivalent strain indicates a smoother chipping process.

Figure 14
Figure 14 illustrates the temperature analysis of the workpiece.Figure 14(a) describes temperature of counter clockwise feed.The maximum temperature is at the cutting part of the blade.The maximum temperature is 99.1 o C.Figure 14(b) shows temperature of clockwise feed.The maximum temperature is at the cutting part of the blade.The maximum temperature was 31 o C. Figure 15 represents the state variable analysis of the temperature.Figure 15(a) describes the state variable analysis counter-clockwise feed.The temperature curve illustrates fluctuations of different sizes.Figure 15(b) describes the state variable analysis the clockwise feed.The temperature curve shows fluctuations of different sizes.Figure 16 illustrates the stochastic gradient descent method of the effective strain.Figure 16(a) describing the predicted curve of temperature goes up smoothly.Figure 16(b) representing the predicted curve of temperature goes up smoothly.

Figure 14 .Figure 16 .
Figure 14 illustrates the temperature analysis of the workpiece.Figure 14(a) describes temperature of counter clockwise feed.The maximum temperature is at the cutting part of the blade.The maximum temperature is 99.1 o C.Figure 14(b) shows temperature of clockwise feed.The maximum temperature is at the cutting part of the blade.The maximum temperature was 31 o C. Figure 15 represents the state variable analysis of the temperature.Figure 15(a) describes the state variable analysis counter-clockwise feed.The temperature curve illustrates fluctuations of different sizes.Figure 15(b) describes the state variable analysis the clockwise feed.The temperature curve shows fluctuations of different sizes.Figure 16 illustrates the stochastic gradient descent method of the effective strain.Figure 16(a) describing the predicted curve of temperature goes up smoothly.Figure 16(b) representing the predicted curve of temperature goes up smoothly.

Figure 17
Figure17illustrates the wear depth (mm) analysis of the spiral flat bottom engraver.Figure17(a)describes wear depth of counter clockwise feed that maximum was 0.0609 mm.Figure17(b)shows wear depth of clockwise feed that maximum was 0.121 mm.Figure17(a) and Figure17(b)show opposite wear positions.The clockwise cutting produces greater wear.Figure18describes the spiral flat bottom engraving.Figure18(a) illustrates front view the spiral flat bottom engraving.Figure18 (b)shows right view the spiral flat bottom engraving.The location of tool wear is consistent with the simulation analysis.