An Analytical Representation of Chip Area for Corner-Radiused Tools Under Both Depth-of-Cut and Feed Variations

1999 ◽  
Vol 122 (4) ◽  
pp. 660-665 ◽  
Author(s):  
O. Burak Ozdoganlar ◽  
William J. Endres

The operation of corner-radiused tools under both depth-of-cut and feed variation is a situation that occurs for many processes (e.g., straight turning, contour turning, boring, and face-milling) and under many practical conditions. A new chip-area expression is formulated by applying a rotational transformation to the chip-area geometry. Results obtained with this new representation are compared to an exact area computation algorithm based on geometric shapes. The new representation and its associated expressions are far more simple than those of the exact area representation. The errors introduced by the new representation have been analyzed and found to be very small. To increase the accuracy of the expressions for numerical applications, numerical and analytical error-compensation functions have been developed. The latter makes the expressions exact, at the expense of increased algorithmic content, whereas the former is less algorithmic with negligible errors even under extreme conditions. [S1087-1357(00)00404-4]

2016 ◽  
Vol 4 (2) ◽  
Author(s):  
Abdolreza Bayesteh ◽  
Junghyuk Ko ◽  
Martin Byung-Guk Jun

There is an increasing demand for product miniaturization and parts with features as low as few microns. Micromilling is one of the promising methods to fabricate miniature parts in a wide range of sectors including biomedical, electronic, and aerospace. Due to the large edge radius relative to uncut chip thickness, plowing is a dominant cutting mechanism in micromilling for low feed rates and has adverse effects on the surface quality, and thus, for a given tool path, it is important to be able to predict the amount of plowing. This paper presents a new method to calculate plowing volume for a given tool path in micromilling. For an incremental feed rate movement of a micro end mill along a given tool path, the uncut chip thickness at a given feed rate is determined, and based on the minimum chip thickness value compared to the uncut chip thickness, the areas of plowing and shearing are calculated. The workpiece is represented by a dual-Dexel model, and the simulation properties are initialized with real cutting parameters. During real-time simulation, the plowed volume is calculated using the algorithm developed. The simulated chip area results are qualitatively compared with measured resultant forces for verification of the model and using the model, effects of cutting conditions such as feed rate, edge radius, and radial depth of cut on the amount of shearing and plowing are investigated.


2012 ◽  
Vol 426 ◽  
pp. 339-343 ◽  
Author(s):  
Qiu Lin Niu ◽  
X.J. Cai ◽  
Zhi Qiang Liu ◽  
Ming Chen ◽  
Qing Long An

As a typical high strength material, titanium alloy Ti-6Al-2Sn-4Zr- 2Mo-0.1Si (TA19) is used to manufacturing the compressor power-brake of aircraft engine and the aircraft skin. All the machining experiments were carried out on a CNC-milling center under the stable conditions of cutting speed, feed rate, and depth of cut. The performance and wear mechanisms of coated- and uncoated carbide tools have been investigated in this paper to evaluate the machinability of TA19 in face milling. The three tools used were PVD-TiN+TiAlN, CVD-TiN+Al2O3+TiCN and uncoated carbide inserts. The results indicated that PVD coating had the best performance than other tool materials in milling titanium alloy TA19, and the cutting force and the wear value were the smallest than that for CVD-coated and uncoated tools. The failure types of PVD-, CVD- and uncoated inserts were the crater wear and micro tipping; the crater wear and tipping; tipping. Abrasive wear and adherent wear were the predominant mechanism of PVD-TiN+TiAlN carbide insert in face milling TA19 alloy. For CVD- and uncoated carbide, adherent wear was predominant.


1985 ◽  
Vol 107 (2) ◽  
pp. 99-106 ◽  
Author(s):  
R. Komanduri ◽  
M. Lee

The salient features of a simple, wear-tolerant cemented carbide tool are described. Results are presented for high-speed machining (3 to 5 times the conventional speeds) of titanium alloys in turning and face milling. This tool, termed the ledge cutting tool, has a thin (0.015 to 0.050 in.) ledge which overhangs a small distance (0.015 to 0.060 in.) equal to the depth of cut desired. Such a design permits only a limited amount of flank wear (determined by the thickness of the ledge) but continues to perform for a long period of time as a result of wear-back of the ledge. Under optimum conditions, the wear-back occurs predominantly by microchipping. Because of geometric restrictions, the ledge tool is applicable only to straight cuts in turning, facing, and boring, and to face milling and some peripheral milling. Also, the maximum depth of cut is somewhat limited by the ledge configuration. In turning, cutting time on titanium alloys can be as long as ≈ 30 min. or more, and metal removal of ≈ 60 in.3 can be achieved on a single edge. Wear-back rates in face milling are about 2 to 3 times higher than in straight turning. The higher rates are attributed here to the interrupted nature of cutting in milling. Use of a grade of cemented carbide (e.g., C1 Grade) which is too tough or has too thick a ledge for a given application leads to excessive forces which can cause gross chipping of the ledge (rapid wear) and/or excessive deflection of the cutting tool with reduced depth of cut. Selection of a proper grade of carbide (e.g., Grades C2, C3, C4) for a given application results in uniform, low wear-back caused by microchipping. Because of the end cutting edge angle (though small, ≈ 1 deg) used, the ledge tool can generate a slight taper on very long parts; hence an N.C. tool offset may be necessary to compensate for wear-back. The ledge tool is found to give excellent finish (1 to 3 μm) in both turning and face milling. In general, conventional tooling with slight modifications can be used for ledge machining. The ledge tool can also be used for machining cast iron at very high speeds.


Author(s):  
P. Singh ◽  
J. S. Dureja ◽  
H. Singh ◽  
M. S. Bhatti

Machining with minimum quantity lubrication (MQL) has gained widespread attention to boost machining performance of difficult to machine materials such as Ni-Cr alloys, especially to reduce the negative impact of conventional flooded machining on environment and machine operator health. The present study is aimed to evaluate MQL face milling performance of Inconel 625 using nano cutting fluid based on vegetable oil mixed with multi-walled carbon nanotubes (MWCNT). Experiments were designed with 2-level factorial design methodology. ANOVA test and desirability optimisation method were employed to arrive at optimised milling parameters to achieve minimum tool wear and machined surface quality. Experiments were performed under nanoparticles based minimum quantity lubrication (NMQL) conditions using different weight concentrations of MWCNT in base oil: 0.50, 0.75, 1, 1.25 and 1.5 wt. %; and pure MQL environment (without nanoparticles). The optimal MQL milling parameters found are cutting speed: 47 m/min, table feed rate: 0.05 mm/tooth and depth of cut: 0.20 mm. The results revealed improvement in the surface finish (Ra) by 17.33% and reduction in tool flank wear (VB) by 11.48 % under NMQL face milling of Inconel 625 with 1% weight concentration of MWCNT in base oil compared to pure MQL machining conditions.


2019 ◽  
Vol 9 (1) ◽  
pp. 65-72
Author(s):  
Mohammad Zaher Akkad ◽  
Felhő Csaba

This paper presents a study about the workpiece force components (Fx, Fy, Fz) changes in face milling, which results from changing the depth of cut and the feed rate values. The values of the three force components in the face milling operation were found through the FEA-software AdvantEdge by Third Wave Systems. This program is uniquely intended for modelling of cutting processes. Simulations were carried out within five different cutting depth of cut and feed rate, to compare the obtained values and find out the results of the impact of changes on the three force components.


2021 ◽  
pp. 200-206
Author(s):  
I.N. Sedinin ◽  
V.F. Makarov

It is considered the complex of operations of the technological process for the heat treatment of steel 95X18-Sh, as a result of which the material of the samples increases the hardness to 59...61 HRC, and also improves the physical and mechanical properties. A full-scale full factorial experiment of face milling of samples was carried out using the method of mathematical planning. In the experiments, a high-precision machine and a carbide cutting tool were used. To calculate the values of the roughness function, the following are taken as independent variables: cutting speed, feed per tooth and depth of cut. In order to determine the coefficients of the linear equation, a central compositional orthogonal plan of the second order for three factors was used. A matrix of levels of variation of independent variable factors and a matrix of experiment planning were compiled. A regression analysis of the obtained experimental statistical data was carried out using the Microsoft Excel, Statistica and Wolfram Alpha programs. As a result of the calculations, a mathematical model of the roughness of the machined surface and optimal cutting conditions were determined.


Author(s):  
Raj Sekhar Mandal ◽  
Santanu Das ◽  
Partha Pratim Saha

Undesirable burrs are created out of a machining process. The objective of the present work is to explore the suitable condition to obtain no burr, or negligible burr, around the edge of a machined product at wet condition. Face milling experiments have been carried out on blocks made of aluminum alloy (Alloy-4600M) with a single, coated-carbide inserted cutter for observing the nature of burr formation. Depth of cut has been maintained constant at 3 mm for all sets of experiments. In each experiment set, three cutting velocities (170 m/min, 237 m/min and 339 m/min) and three in-plane exit angles of 30°, 60° and 90° are provided at three different feeds of 0.08 mm/tooth, 0.1 mm/tooth and 0.12 mm/tooth. First set of experiments are done without any exit edge bevel. Similar sets of experiments are carried out with 15° and 30° exit edge bevel angles to find out the condition for minimum burr. The bevel is made of a height of 3 mm. In the present experimental investigation, a minimum burr height of as low as 3 micron is obtained at an in-plane exit angle of 30° and exit edge bevel angle of 15° under the machining condition of 339 m/min cutting velocity and 0.1 mm/tooth feed.


Author(s):  
M. Salahshoor ◽  
Y. B. Guo

Biodegradable magnesium-calcium (Mg-Ca) implants have the ability to gradually dissolve and absorb into the human body after implantation. The critical issue that hinders the application of Mg-Ca implants is its poor corrosion resistance to human body fluids. A promising approach to tackle this issue is tailoring the surface integrity characteristics of the orthopedic implants to get an appropriate corrosion kinetic. High speed face milling of biodegradable Mg-Ca alloy is used in this study as a possible way to achieve that goal. Polycrystalline diamond inserts are used to avoid material adhesion and likely fire hazards. All the cutting tests are performed without using coolant to keep the manufacturing process ecological. High cutting speed of 40 m/s and 200 μm depth of cut are applied in a broad range of feed values to cover finish and rough cutting regimes. The effect of feed as a key machining parameter which defines the amount and duration of thermo-mechanical load and ultimately provides higher chances for surface integrity changes are investigated.


2014 ◽  
Vol 931-932 ◽  
pp. 354-359 ◽  
Author(s):  
Surasit Rawangwong ◽  
Worapong Boonchouytan ◽  
Jaknarin Chatthong ◽  
Romadorn Burapa

The purpose of this research was to investigate the effect of the main factors on the surface roughness in mold steels face milling by carbide tool for results obtained from the analysis used in the manufacture of molds and other parts of the industry. The etching experiment using semi-automated milling machine Obraeci Strojie brand FGV 32 model. Concerning the material was steel grade AISI P20 mold with a hardness between 280-325 HB which used to insert carbide tool. The factors of a speed, feed rate and depth of cut were study. Preliminary experiments showed that the depth does not affect the surface roughness fix depth of cut at 0.5 mm. The experimental revealed that the factor affecting surface roughness was feed rate and speed. The roughness value trenced to reduce at lower feed rate and greater speed. It was possible determine a facing condition by means of the equation Ra = 1.29 - 0.000654Speed + 0.00305Feed rate leading this equation goes to use is in limitation speed 500-1,000 rpm. at feed rate 160-315 mm/min. From the experiment was confirming the result of a comparison between the equation and the percent accuracy with the margin of error. The result from the experiment of mean absolute percentage error (MAPE) of the equation of surface roughness was 3.27% which was less than the margin of error and was acceptable. The pattern of wear was similar to mechanical fatigue cracking. It may be due to the verious tip of the cutting tool or an impact and flank wear as cutting tool materials resistant to wear less.


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