Effects of Machining Parameters on the Microhardness of Chips

1989 ◽  
Vol 111 (3) ◽  
pp. 220-228 ◽  
Author(s):  
V. K. Jain ◽  
S. Kumar ◽  
G. K. Lal
Keyword(s):  
Shear Strain ◽  
Cutting Tools ◽  
Cutting Speed ◽  
Shear Angle ◽  
Interface Temperature ◽  
Machining Parameters ◽  
Machining Conditions ◽  
Temperature Shear ◽  
Longitudinal Turning ◽  
Microhardness Tester

It has been found that the shear strain acceleration governs the machining parameters like tool-chip interface temperature, shear angle, tool wear, etc. It is therefore speculated that microhardness of the chips for the same machining conditions but for different shear strain accelerations would be different. To test this hypothesis, experiments have been conducted using mild steel as work material and cemented carbide bits as cutting tools. Experiments were performed in two ways: longitudinal turning and accelerated cutting. Chips were collected at the same machining conditions but at different shear strain acceleration. Microhardness of the chips has been measured using the Leibtz-microhardness tester and the results have been analyzed using a computer program CADEAG-1. Using the responses (i.e., microhardness), mathematical models have been evolved. Effects of different parameters (cutting speed, feed, etc.) on the microhardness of the chips in all the three cases (i.e., longitudinal turning, facing, and taper turning) have been studied. It has been concluded that the microhardness of the chips obtained during accelerated cutting is governed by the shear strain acceleration and its governing parameters.

scholarly journals Machining of Aluminums Alloys with the Addition of Reinforced Carbide Phase

2020 ◽  
Vol 60 (1) ◽  
pp. 11-20
Author(s):  
Piotr Putyra ◽  
Marcin Podsiadło ◽  
Lucyna Jaworska ◽  
Jolanta Laszkiewicz-Łukasik ◽  
Maciej Dyzia ◽  
...  
Keyword(s):  
Volume Fraction ◽  
Cutting Tools ◽  
Cutting Speed ◽  
Aluminum Matrix ◽  
Polycrystalline Diamond ◽  
Cutting Parameters ◽  
Machining Parameters ◽  
Ceramic Phase ◽  
The Matrix ◽  
Longitudinal Turning

This paper presents the results of the processes of treating aluminum matrix casting materials with the addition of a ceramic phase. The matrix of the composite material was an Al-Si7 casting alloy with addition of 2 mass% Mg. The volume fraction of the reinforcing phase in the form of silicon carbide ranged from 5 to 15 vol.%. Preliminary machining tests were carried out at the Mori Seiki NL2000SY turning and milling center. The cutting properties were evaluated during longitudinal turning. Cutting tests were carried out using tools made of polycrystalline diamond, regular boron nitride, and cemented carbides. The nature of VBB wear was checked in accordance with PN-ISO 3685:1996. The influence of machining parameters (cutting speed, feed, cutting depth) on the value of cutting tools temperature was determined. An analysis of the chip shaping mechanism during machining was performed at various cutting parameters. The tests were carried out using the FLIR A655 thermal imaging camera and the fast Phantom MIRO M310 fast camera. Cast composite materials were also subjected to the processes of waterjet cutting, EDM cutting, and EDM drilling (EDM electro discharge machining).

Analysis of tool vibration and surface roughness during turning process of tempered steel samples using Taguchi method

2021 ◽  
pp. 095440892110019
Author(s):  
Menderes Kam ◽  
Mustafa Demirtaş
Keyword(s):  
Surface Roughness ◽  
Taguchi Method ◽  
Cutting Tools ◽  
Cutting Speed ◽  
Machining Parameters ◽  
Turning Process ◽  
Machining Time ◽  
Tool Vibration ◽  
Control Factors ◽  
Tempered Steel

This study analyzed the tool vibration (Vib) and surface roughness (Ra) during turning of AISI 4340 (34CrNiMo6) tempered steel samples using Taguchi Method. In this context, Taguchi design L18 (21 × 32) was used to analyze the experimental results. The vibration amplitude values from cutting tools were recorded for different machining parameters, control factors; two different sample hardness (46 and 53 HRc), three different cutting speeds (180, 220, 260 m.min−1), and feed rates (0.08, 0.14, 0.20 mm.rev−1) were selected. The machining parameters giving optimum Vib and Ra values were determined. Regression analysis is applied to predict values of Vib and Ra. Analysis of variance was used to determine the effects of machining parameters on the Vib and Ra values. The most important machining parameters were found to be the feed rate, sample hardness, and cutting speed for Vib and Ra, respectively. The lowest Vib and Ra values were obtained in 46 HRc sample as 0.0022 gRMS and 0.255 µm, respectively. The surface quality can be improved by reducing the sources of vibration by using appropriate machining parameters. As a result, there is a significant relationship between Ra and Vib. The lower Ra values were found during turning process of tempered steel samples according to the literature studies. It is suggested that the process can be preferred as an alternative process to grinding process due to lower cost and machining time. In application of the turning of experiment samples by ceramic cutting tool, a substantial technological and economical benefit has been observed.

Multiresponse optimization of drillability factors and mechanical properties of chitosan-reinforced polypropylene composite

2020 ◽  
pp. 089270572093916
Author(s):  
Nafiz Yaşar ◽  
Mustafa Günay ◽  
Erol Kılık ◽  
Hüseyin Ünal
Keyword(s):  
Surface Roughness ◽  
Feed Rate ◽  
Thrust Force ◽  
Flexural Modulus ◽  
Cutting Speed ◽  
Industrial Applications ◽  
Uniaxial Tensile ◽  
Machining Parameters ◽  
Molding Method ◽  
Machining Conditions

In this study, the mechanical and machinability characteristics of chitosan (Cts)-filled polypropylene (PP) composites produced by injection molding method were analyzed. Uniaxial tensile, impact, hardness, and three-point flexural tests were used to observe the influence of Cts filler on the mechanical behavior of PP. For the machinability analysis of these materials, drilling experiments based on Taguchi’s L27 orthogonal array were performed using different drill qualities and machining parameters. Then, machining conditions are optimized through grey relational analysis methodology for machinability characteristics such as thrust force and surface roughness obtained from drilling tests. The results showed that tensile, flexural strength, and percentage elongation decreased while impact strength increased with adding the Cts filler to PP. Moreover, it was determined that the tensile and flexural modulus of elasticity increased significantly and there was a slight increase in hardness. Thrust forces decreased while surface roughness values increased when the Cts filler ratio and feed rate was increased. The optimal machining conditions for minimizing thrust force and surface roughness was obtained as PP/10 wt% Cts material, uncoated tungsten carbide drill, feed rate of 0.05 mm/rev, and cutting speed of 40 m/min. In this regard, PP composite reinforced by 10 wt% Cts is recommended for industrial applications in terms of both the mechanical and machinability characteristics.

Machinability of Pearlitic Cast Iron With Cubic Boron Nitride (CBN) Cutting Tools

2002 ◽  
Vol 124 (4) ◽  
pp. 820-832 ◽  
Author(s):  
Jiancheng Liu ◽  
Kazuo Yamazaki ◽  
Hiroyuki Ueda ◽  
Norihiko Narutaki ◽  
Yasuo Yamane
Keyword(s):  
Cast Iron ◽  
Boron Nitride ◽  
Tool Wear ◽  
High Speed ◽  
Cubic Boron Nitride ◽  
Cutting Tools ◽  
Cutting Temperature ◽  
Cutting Speed ◽  
Machining Conditions ◽  
Machining Center

In order to increase the accurate finishing productivity of pearlitic cast iron, face milling by CBN (Cubic Boron Nitride) cutting tools was studied. The main focus of the study is the machinability investigation of pearlitic cast iron with CBN cutting tools by studying the relationships among machining conditions such as feed rate, cutting speed as well as CBN cutting tool type, tool wear, workpiece surface quality, cutting forces, and cutting temperature. In addition, an emphasis is put on the effect of Al additive in pearlitic cast iron on its machinability and tool wear characteristics. High-speed milling experiments with CBN cutting tools were conducted on a vertical machining center under different machining conditions. The results obtained provide a useful understanding of milling performance by CBN cutting tools.

On the Effects of a Built-Up Edge on Acoustic Emission in Metal Cutting

1990 ◽  
Vol 112 (2) ◽  
pp. 184-189 ◽  
Author(s):  
D. V. Hutton ◽  
Qinghuan Yu
Keyword(s):  
Acoustic Emission ◽  
Experimental Evidence ◽  
Deformation Zone ◽  
Metal Cutting ◽  
Cutting Tools ◽  
Cutting Speed ◽  
Rake Angle ◽  
Shear Angle ◽  
Cutting Conditions ◽  
Effective Rake Angle

Experimental evidence is presented which indicates that the presence of a built-up edge can significantly affect the generation of acoustic emission in metal cutting. Results for machining SAE 1018 and 4140 steels show that the built-up edge can mask the generally accepted AE-cutting speed relation when cutting tools having small rake angles are used. Under cutting conditions conducive to development of a built-up edge, it is shown that increased acoustic emission is generated as a result of increased effective rake angle and corresponding increase of shear angle in the primary deformation zone. Three distinct types of built-up edge have been observed and classified as immature, periodic, or developed, according to effect on acoustic emission.

Effects of Accelerated Tests on Shear Flow Stress in Machining

1987 ◽  
Vol 109 (3) ◽  
pp. 206-212 ◽  
Author(s):  
V. K. Jain ◽  
B. K. Gupta
Keyword(s):  
Flow Stress ◽  
Shear Flow ◽  
Shear Strain ◽  
Tool Material ◽  
Interface Temperature ◽  
Accelerated Tests ◽  
Instantaneous Values ◽  
Longitudinal Turning ◽  
Materials Behavior ◽  
Shear Flow Stress

Facing and taper turning tests (also known as accelerated cutting tests) are commonly used for the evaluation of machinability of materials. Of late, it has been reported that instantaneous values of tool-chip interface temperature, tool wear, shear angle, etc, in longitudinal turning are different from the corresponding values in accelerated cutting. This effect has been attributed to shear strain acceleration phenomenon. Materials behavior during accelerated cutting changes in a manner different than that in longitudinal turning. To test this hypothesis, experiments have been conducted using HSS as tool material and mild steel as work material. It has been concluded that shear flow stress during accelerated cutting is governed by shear strain acceleration and its governing parameters. Shear flow stress value is highest during facing, lowest in taper turning and in between the two during longitudinal turning.

Experimental Investigation of Machining Parameters during Turning of AISI 316L Stainless Steel Using Nano Cutting Environment

2015 ◽  
Vol 787 ◽  
pp. 361-365 ◽  
Author(s):  
T. Rajmohan ◽  
S.D. Sathishkumar ◽  
K. Palanikumar
Keyword(s):  
Stainless Steel ◽  
Feed Rate ◽  
316L Stainless Steel ◽  
Cutting Speed ◽  
Interface Temperature ◽  
Depth Of Cut ◽  
Machining Parameters ◽  
Aisi 316L ◽  
Machining Processes ◽  
Aisi 316L Stainless Steel

In modern machining processes, there are continuous cost pressures and high quality expectations in the product. Hence, it is required to explore the techniques that can reduce the cost and also increase the quality of the product. In the present work, machining performance of AISI 316L SS is assessed by the performing turning operation under nano cutting environment. Experiments have been carried out by plain turning of 48mm diameter and 600mm long rod of AISI 316L stainless steel on all geared lathe at different cutting velocities and feeds under wet machining with and without Carbon nano Tubes (CNT) inclusions using carbide inserts. The effect of cutting speed, feed rate, depth of cut on tool chip interface temperature and surface roughness are analysed using Taguchi method. Furthermore, using analysis of variance method, significant contributions of process parameters have been determined. Experimental results reveal that feed rate and cutting speed are the dominant variables on responses.

Minimized Wear and Debris Generation Through Optimized Machining of Co-Cr-Mo Alloys for Use in Metal-on-Metal Hip Implants

2012 ◽  
Author(s):  
Ashish Deshpande ◽  
Shu Yang ◽  
Dave Puleo ◽  
David Pienkowski ◽  
Oscar Dillon ◽  
...  
Keyword(s):  
Residual Stresses ◽  
Wear Debris ◽  
Wear Behavior ◽  
Cutting Speed ◽  
Machining Process ◽  
Depth Of Cut ◽  
Machining Parameters ◽  
Machining Conditions ◽  
Metal On Metal ◽  
Tool Edge

More than 380,000 hips are replaced with total joint prostheses each year in the U.S. Wear debris generated by metal-on-metal implant designs is of concern due to potential adverse biological effects arising from chronic exposure of human tissue to the wear debris. This paper presents a new methodology for optimizing the wear performance of prosthesis made of Co-Cr-Mo alloys by varying tool edge geometry and machining conditions to alter the wear behavior of this alloy, while also controlling the residual stresses induced during the machining process. The machining process causes inhomogeneous inelastic deformations near the surface layer of machined parts which create residual stresses in the surface of machined components. Residual stresses in the machined surface and the subsurface are affected by cutting tool material, tool geometry, workpiece, tool-work interface conditions, and the cutting parameters such as feed rate, depth of cut and cutting speed. In the current work, residual stresses were measured using X-ray diffraction technique (XRD). The surface residual stresses in two directions (radial and hoop) were measured on the machined pins after machining with different machining conditions, but prior to the wear test. Wear behavior of Co-Cr-Mo alloy pin specimens, produced from machining with varying tool edge geometry and machining conditions, was studied using a custom-made biaxial motion pin-on-disc tribological testing system in which the pin specimen is immersed in a simulated bio-fluid environment. Wear-induced weight loss (± 10 μg) and changes in surface roughness (± 0.001 μm) were obtained at 100,000 cycle intervals upto 500,000 cycles. Metallographic analysis was performed on the machined pin specimens to analyze the microstructure and microhardness before and after testing. The rate of wear for the specimens was lowest for those pins where the change of the subsurface microhardness was small due to prevention of additional steady state wear after the initial run-in wear in the wear tester. A combination or response surface methodology and genetic algorithm (GA) was used in to optimize the various machining parameters for minimized wear generation. The optimal combination of the four machining parameters (feed 0.18mm/rev, nose radius 0.6 mm, cutting speed 27.6 m/min and depth of cut 0.38) produced the largest compressive residual stresses on the surface and subsurface of the implants thereby reducing the wear/debris generation by about fifty percent.

Optimisation of Machining Parameters for Milling Polyetheretherketones (PEEK) Biomaterial

2014 ◽  
Vol 699 ◽  
pp. 198-203 ◽  
Author(s):  
Raja Izamshah Raja Abdullah ◽  
Aaron Yu Long ◽  
Md Ali Mohd Amran ◽  
Mohd Shahir Kasim ◽  
Abu Bakar Mohd Hadzley ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Feed Rate ◽  
Cutting Tools ◽  
Cutting Speed ◽  
Processing Parameters ◽  
Machining Process ◽  
Depth Of Cut ◽  
Machining Parameters ◽  
Dimensional Precision ◽  
Good Surface

Polyetheretherketones (PEEK) has been widely used as biomaterial for trauma, orthopaedic and spinal implants. Component made from Polyetheretherketones generally required additional machining process for finishing which can be a problem especially to attain a good surface roughness and dimensional precision. This research attempts to optimize the machining and processing parameters (cutting speed, feed rate and depth of cut) for effectively machining Polyetheretherketones (PEEK) implant material using carbide cutting tools. Response Surface Methodology (RSM) technique was used to assess the effects of the parameters and their relations towards the surface roughness values. Based on the analysis results, the optimal machining parameters for the minimum surface roughness values were by using cutting speed of 5754 rpm, feed rate of 0.026 mm/tooth and 5.11 mm depth of cut (DOC).

A Study on the Surface Characteristics with the Vibration Factor in the Micro-Machine

2006 ◽  
Vol 321-323 ◽  
pp. 1605-1608
Author(s):  
Jong Min Kin ◽  
Min Sung Hong ◽  
Bong Suk Kim ◽  
Soo Hun Lee
Keyword(s):  
Great Influence ◽  
Cutting Speed ◽  
Surface Characteristics ◽  
Surface Shape ◽  
System Stability ◽  
Micro Milling ◽  
Machining Parameters ◽  
Machining Conditions ◽  
The Difference ◽  
Micro Machine

In conventional machining, cutting conditions such as cutting speed, feed rate, and depth of the cut have great influence on the surface roughness. In micro machining, however, the surface shape is affected by not only the machining parameters mentioned earlier but also tool stiffness, system stability, and workpiece properties caused by the miniatured structure and cutting tool. Especially, in a micro-machine system, the difference between the cutting forces in the recursive cuts introduces the vibration easily. A high spindle causes instability of the system, increases the temperature in the cutting process, and also changes the tool’s shape. This study introduces a method to predict the surface shape of the workpiece based on the machining conditions in micro milling. The micro-milled surfaces in different machining conditions are predicted by a computer simulation including the vibration model and the simulated results show good agreement with the experimental results.

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