Side Cutting Edge Angle Research Articles

Effect of the Side Cutting–Edge Angle on the Surface Roughness for Aluminum 1350 in the Turning Operation by Taguchi Method

The purpose of this work was to analyze the effect of the side cutting-edge angle on the surface roughness of aluminum 1350 in a turning operation. A Taguchi design L32 was used in this work; the control variables were spindlespeed, feed rate, depth of cutting and the side cutting-edge angle. Several metal cutting experiments and statistical tests provide evidence that the side cutting-edge angle significantly affects the surface roughness with a Statistical F equal to 24.96, mainly, when the side cutting-edge angle is maintained at high level; in this study, the high level was kept to 5.0 degrees. Also, when the high level condition is kept, it causes a major variation of the residual values; consequently, the surface roughness of the workpiece falls out of the specifications demanded by customers.Moreover, the best combination of the cutting parameters for a minimum surface roughness equal to 23.5 μin wasobtained. Finally, further research directions are presented.

S1302-1-2 ダイヤモンド平バイトによる単結晶シリコンの高能率旋削加工技術の開発(超精密加工(1))

Turning of single crystal silicon on a (100) surface was carried out using straight-nosed single crystal diamond cutting tool with a rake angle of -20°, and a side cutting edge angle of 5°. This side cutting edge angle enables the turning of silicon in high depth of cut. The surface roughness of the work piece was about 20nm PV, when the feed speed of the tool was 0.3mm/min and 0.6mm/min, depth of cut was 10μm, revolution speed of the work piece was 3000min^<-1>. During the turning of silicon, cutting force was measured by using cutting force dynamometer, and relation between the cutting force and tool feed speed was also investigated.

Investigation of chip-back temperature during machining depending on cutting parameters

In this study, measurement of the chip-back temperature developed during cutting was investigated using an embedded thermocouple into the cutting tool. AISI 1117 steel was used as the workpiece material and a K type thermocouple was used for the temperature measurement. The cutting tool used was uncoated and without chip braker and in the form of SCMW 12 M508-S2F according to ISO 1832. This cutting tool was fixed on a tool holder in the form of SSBCR 25 25 M12 and the side cutting edge angle during tests was 75° as suggested in ISO 3685. The cutting tests were carried out on a Johnford TC35 CNC turning center. In selecting the cutting parameters, the reference values indicated in ISO 3685 were used. In order to locate the thermocouple on the cutting tool, a Flir Systems Therma Cam thermal camera was used. The results showed that increasing cutting speed, feed rate and depth of cut resulted in increase in the temperature at the back rake surface. However, cutting speed had the most influence on the temperature.

Dry turning of tempered martensitic stainless tool steel using coated cermet and coated carbide tools

Turning trials were performed under dry cutting conditions with constant depth of cut in order to investigate the usability of coated TiCN based cermet (KT 315) and coated carbide (KC 9110) cutting tools to turn tempered martensitic stainless tool steel with hardness in the 43–45 HRC range. Cutting speed, feed and the side cutting edge angle (SCEA) of the tool were the independent variables considered. Regardless of the cutting tool material, cutting speed and feed expectedly have an effect on tool wear and tool life. Additionally, the SCEA is found to influence the tool life where the tool life increases, as the SCEA was changed from 0° to −5°. The longest tool life was attainable when cutting with KT 315 at low cutting speed and feed rate when using −5° SCEA. However, in all other instances, KC 9110 outperforms KT 315. This is particularly evident at medium and high cutting speeds and feed. The constant and exponent for the various Taylor tool life equations have been determined. Flank wear, end clearance wear and catastrophic failure were the main types of tool failure mode determining tool life. The wear mechanisms for the various tool failure modes were suggested. The results suggest that dry turning of hardened, stainless tool steel could be performed using coated TiCN based cermet and coated carbide cutting tools with −5° SCEA at suitably selected cutting speed and feed combination.

The Effect of Cutting Tool Material and Edge Geometry on Tool Life and Workpiece Surface Integrity

Titanium alloys are used extensively in the aerospace industry and are generally classified as ‘hard to machine’. The combination of high strength at elevated temperatures, low thermal conductivity, low modulus of elasticity, and high chemical affinity with all available cutting tool materials means that there are inherent difficulties when machining. The extensive literature detailing all aspects of the machinability of titanium alloys is briefly reviewed; however, little of this refers specifically to surface integrity, which is critical to industries such as aerospace. This paper focuses on the effects that insert geometry had on tool life and workpiece surface integrity when cutting speed, feed rate, and depth of cut were varied. Specifically the effects of edge radius, side cutting edge angle, and edge land are considered. The findings show that whatever combination of tool geometry and operating parameters were used, the surface integrity is remarkably similar, even at relatively high cutting speeds and feed rates.

Facing SiCp/Mg metal matrix composites with carbide tools

TiCN/TiN coated carbide cutting tools were used to study the finish machining characteristics of a silicon carbide particle reinforced magnesium metal matrix composite (SiCp/Mg MMC). A fully replicated two-level 2 4 full factorial with centerpoints was conducted while facing the MMC with process variables including feed, cutting speed, depth of cut and side cutting edge angle; and response variables of cutting forces, chip formation, surface roughness and tool wear. Results showed both continuous and semi-continuous chips were formed with the machining conditions used in this study. Abrasive wear of the flank face was observed to be the dominant tool-wear mechanism for all conditions within this study. It was observed that a greater depth of cut reduced the amount of tool wear for a given volume of material removed. Surface roughness values were within the range of 0.2–3.0 μm.

Application of response surface methodology in describing the performance of coated carbide tools when turning AISI 1045 steel

The performance of a multilayer tungsten carbide tool was described using response surface methodology (RSM) when turning AISI 1045 steel. Cutting tests were performed with constant depth of cut and under dry cutting conditions. The factors investigated were cutting speed, feed and the side cutting edge angle (SCEA) of the cutting edge. The main cutting force, i.e. the tangential force and surface roughness were the response variables investigated. The experimental plan was based on the face centred, central composite design (CCD). The experimental results indicate that the proposed mathematical models suggested could adequately describe the performance indicators within the limits of the factors that are being investigated. The feed is the most significant factor that influences the surface roughness and the tangential force. However, there are other factors that provide secondary contributions to the performance indicators. In the case of surface roughness, the SCEA 2 and the interaction of feed and SCEA provides these contributions whilst for tangential force, the SCEA 2, the interaction of feed and SCEA; and the cutting speed provides them.

Performance evaluation of cemented carbide tools in turning AISI 1010 steel

In this paper, the performance of three cemented carbide cutting tools, two coated tungsten based cemented carbide — one with Al 2O 3 (black) outer layer and the other with TiN (golden), and an uncoated titanium based (silver grey) cemented carbide tool, with 80° — diamond insert shape were investigated during finish turning of AISI 1010 steel. The PCBNR tool holder, giving a side cutting edge angle of +15°, was used. Cutting tests were performed with constant depth of cut and at various cutting speeds and feed rates to investigate the performance of the tools under dry cutting conditions. Cutting forces and surface roughness were measured. The chips produced by the three type of tools during experimental trials were examined to determine the secondary shear zone, chip thickness and the angle of maximum crystal elongation. The tool which had the CVD with TiCN/TiC and PVD with TiN coating layer sequence performs best under the conditions tested, as lower forces with little variation were encountered, very good surface finish could be obtained and chips with minimum SSZ thickness could be produced, that contributed to low chip strain and therefore to low residual stresses on the workpiece surface.

On the ductile machining of silicon for micro electro-mechanical systems (MEMS), opto-electronic and optical applications

The role of hydrostatic pressure in the ductile machining of silicon is demonstrated experimentally using a single crystal diamond tool with a large negative rake (−40°) and a high side cutting edge angle (SCEA) (∼88°) and undeformed chip thickness in the nanometric range (∼50 nm) using an ultraprecision machine tool and a special machining stage inside a high external hydrostatic pressure (∼400 MPa) apparatus.

A comparative study of the effect of tool geometry with negative SCEAs on machining parameters

The objective of this research was to use analytical and experimental approaches to investigate the effects of cutting tool geometry with a negative side cutting edge angle (SCEA) on machining parameters. The first task of this research was to conduct experimental tests for different SCEAs, cutting speeds, feed rates and depths of cut. The second task was to develop a mathematical model to predict cutting forces for the three-dimensional oblique cutting operation. These tasks were accomplished as follows. One set of the experimental results was used as feedback to develop new empirical formulae required to predict cutting forces. A second set of experimental tests was conducted in this study to ensure the validity of the empirical relationships associated with the mathematical model. A comparison of cutting forces and other machining parameters was made between the output of the mathematical model and the experimentally-measured values. New cutting tools are proposed by using the results of the expanded mathematical model. The benefits of this research are as follows: a model for an oblique cutting operation as a function of SCEAs, cutting speeds, feed rates and depths of cut was developed; the effect of negative SCEAs on machining parameters in an oblique cutting process was investigated; and a new direction for designing cutting tool geometry with negative SCEAs, which improves the quality of surface finish and productivity of cutting tool life in turning operations was developed.

セラミックス成形体の被削性に関する研究（第３報）‐切削モデルの検討

In recent years, many ceramics have been to developed for the uses. Some ceramics for mechanical or electronic parts are required to be cut as the green compact. The cutting of the green compact is decreased cracks on the machined surface. The purpose of the paper is to clarify the mechanism at cutting of green compact. The cutting mechanism is investigated and discussed from the results of the fracture test by a new type testing machine and of the cutting test by a lathe. In the cutting test, the radius of cutting edge were varied from 0.8mm to 4mm. A fracture model is proposed from AE(Acoustic Emission) signal caused by fracture and SEM image of fracture surface. The main results obtained are as follows; (1) AE signal shows there stages of fracturing the green compact. (2) The fracture energy is from 4 J/m2 to 7 J/m2. (3) A fracture model is available to clarify the cutting mechanism. (4) The tool with large side cutting edge angle is able to cut a work at high efficiency and to elongate the tool life.

Developing new trends of cutting tool geometry

The objective of this research is to use an analytical and experimental approach to develop new trends of cutting tool geometry with negative Side Cutting Edge Angle (SCEA). The first task of this research is to conduct experimental tests for different SCEAs, cutting speeds, feed rates and depths of cut. This is accomplished as follows. One set of these experimental results will be used as a feedback to develop new empirical formulae required to predict cutting forces and other machining parameters. A second set of experimental tests will be conducted in this study to ensure the validity of the empirical relationships associated with the mathematical model. The second task is to develop a mathematical model to predict cutting forces for the three dimensional oblique cutting operation. New cutting tools will be proposed by using the results of the expanded mathematical model.

Regenerative Chatter Vibration Occurring in Turning With Different Side Cutting Edge Angles

This paper deals with the regenerative chatter vibration occurring in cutting tools with different side cutting edge angles. The occurrence of regenerative chatter vibration of the cutting tool is influenced by two factors, which are closely related to the vibratory energy supply or consumption. One factor is the interference effect between the tool flank and the workpiece. Of course, this factor exists in the primary chatter, too. The other is the regenerative effect. The influence of both factors on the regenerative chatter vibration of cutting tools with different side cutting edge angles is examined experimentally. The vibratory energy supply is simulated, considering the dynamic cutting process. As a result, the property of the regenerative chatter vibration and the influence of the side cutting edge angle on the regenerative chatter vibration are clarified.

マグネシウム合金鋳物ＭＣ２の旋削被削性に及ぼす工具横切れ刃角の影響

Turning machinability tests were performed on the magnesium alloy castings MC2 by measuring cutting resistance, cutting ratio, surface roughness, cutting temperature and chip forming. Regardless of side cutting edge angle, cutting resistance of the alloy was independent of cutting speed, and was affected remarkablly by increasing feed angle. The traversing force decreased with increasing side cutting edge angle. Both cutting ratio and shear angle increased with acceleration of cutting speed and feed. The machined surface finishing showed inferior with increasing side cutting edge angle and feed. The surface roughness with side cutting edge angle 0° was superior or nearly to that calculated theoretically on the basis of feed marks, but the surface roughness with side cutting edge angle 5 to 15° showed higher value. The cutting temperature increased with increasing cutting speed and/or feed. The rising rates of cutting temperature decreased with increase of cutting speed. The highest cutting temperature was 803K. But there was no trouble in flaming during cutting. Both large and small spiral coil type chips were easily treatable.

A study on modification of endrills for finishing holes

High speed drilling has gathered momentum through the use of indexable carbides for hole diameters of 16 to 38 mm. These drills which resemble end mills are also known as endrills. The drills have an outbound and an inbound insert usually of the same shape, square or triangular; one manufacturer even uses a diamond shaped outer insert and a square inner insert. The configuration of these inserts is such that a positive side cutting edge angle, and a negative point angle are obtained. The latter reduces extrusion action at the center thus lowering thrust. Modifications such as introduction of chip splitting grooves, change in point angle, cutting edge angle and relief angle have improved surface roughness and roundness and reduced vibration at the same time.

A study on modification of endrills for finishing holes

High speed drilling has gathered momentum through the use of indexable carbides for hole diameters of 16 to 38 mm. These drills which resemble end mills are also known as endrills. The drills have an outbound and an inbound insert usually of the same shape, square or triangular; one manufacturer even uses a diamond shaped outer insert and a square inner insert. The configuration of these inserts is such that a positive side cutting edge angle, and a negative point angle are obtained. The latter reduces extrusion action at the center thus lowering thrust. Modifications such as introduction of chip splitting grooves, change in point angle, cutting edge angle and relief angle have improved surface roughness and roundness and reduced vibration at the same time.

ＡＺ３１，ＡＺ８０マグネシウム合金押出棒の旋削被削性

The turning machinability of two magnesium alloy bars, AZ31 and AZ80, was evaluated under various conditions using two types of cemented carbide tool, type 31 and type 33, with two rake angles, γ=6° and 12°. According to the results, there was no difference in the cutting resistance between the two samples for all cutting conditions. However, the cutting resistance was dependent on the cutting speed; it increased with the increase of feeding speed. Also, the feed force increased when a side cutting edge angle was applied. In both specimens, the actually machined surface roughness was smaller than the values theoretically calculated. Judging by the chip shape, the ease of processing was either good or acceptable except for the cases in which the feeding speed was small and the cutting speed was high.

Towards improved design of boring bars part 1: Dynamic cutting force model with continuous system analysis for the boring bar performance

The vibrational amplitude is generally large in the case of a boring bar due to its slenderness. A dynamic cutting force model has been presented to take this large amplitude into account. The boring bar is then modelled as a cantilever with this dynamic force acting at the free end and a generalized continuous system model is obtained. This model is solved for the specific case of boring with a zero side cutting edge angle for which published results are available. A reasonably close agreement is found between the proposed model and the experimental results.

Analytical Prediction of Three Dimensional Cutting Process—Part 2: Chip Formation and Cutting Force with Conventional Single-Point Tool

The cutting model and the energy method to predict chip formation and cutting force, which were proposed in the previous part of this study, are extended to machining with conventional single-point tool. The prediction is always possible in the practical range of cutting conditions regardless of size of cutting and tool geometry, if only orthogonal cutting data under equivalent cutting conditions are in hand. The predicted results are verified to be in good agreement with the experimental results in a wide variety of depth of cut, side and back rake angles, side cutting edge angle, and nose radius.

三次元切削過程の動力学

A new analytical method to evaluate the dynamic cutting coefficients in generalized three-dimensional cutting is presented in this paper. The method is developed based on the shear plane model and the static three-dimensional model of gutting, and can determine the stiffness coefficients in dynamic three-dimensional cutting using a few kinds of data obtained by the steady state orthogonal cutting. The dynamic cutting experiments are carried out under various cutting conditions, confirming the validity of the present method. The analytical results as well as experimental ones show the increase of the inner and outer modulation effects with increasing the side cutting edge angle or the nose radius of tool. The results enable one to predict the onset of chatter in any three-dimensional cutting with knowing the dynamic stiffness of machine-tool, tool and workpiece.