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.

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.

Cutting forces analysis of micro-milling process on Inconel 718 – a finite element approach

2020 ◽  
Vol 11 (02) ◽  
pp. 2050011
Author(s):  
Padmaja Tripathy ◽  
Kalipada Maity
Keyword(s):  
Finite Element ◽  
Cutting Forces ◽  
Inconel 718 ◽  
Cutting Speed ◽  
Fem Analysis ◽  
Milling Process ◽  
Machining Process ◽  
Micro Milling ◽  
Depth Of Cut ◽  
Machining Parameters

This paper presents a modeling and simulation of micro-milling process with finite element modeling (FEM) analysis to predict cutting forces. The micro-milling of Inconel 718 is conducted using high-speed steel (HSS) micro-end mill cutter of 1mm diameter. The machining parameters considered for simulation are feed rate, cutting speed and depth of cut which are varied at three levels. The FEM analysis of machining process is divided into three parts, i.e., pre-processer, simulation and post-processor. In pre-processor, the input data are provided for simulation. The machining process is further simulated with the pre-processor data. For data extraction and viewing the simulated results, post-processor is used. A set of experiments are conducted for validation of simulated process. The simulated and experimental results are compared and the results are found to be having a good agreement.

Investigation on Laser Assisted Micro Ball Milling of Inconel 718

2014 ◽  
Vol 660 ◽  
pp. 79-83 ◽  
Author(s):  
E.A. Rahim ◽  
N.M. Warap ◽  
Zazuli Mohid ◽  
R. Ibrahim
Keyword(s):  
Inconel 718 ◽  
Cutting Tool ◽  
Cutting Speed ◽  
Processing Parameters ◽  
Micro Milling ◽  
Depth Of Cut ◽  
Machining Parameters ◽  
New Techniques ◽  
Milling Parameters ◽  
Super Alloy

Micro milling of super alloy materials such as nickel based alloys is challenging due to the excellent of its mechanical properties. Therefore, new techniques have been suggested to enhance the machinability of nickel based alloys by pre-heating the workpiece’s surface to reduce its strength. Determining the processing parameters and their effects to the processing characteristics are crucially important. However, not only the micro-milling parameters need to be considered, but the pre-heating parameters are also need to take into consideration as well. These parameters are expected to improve the machinability. In this study, the experiment of LAMM in Inconel 718 was conducted with considering laser power, cutting speed, depth of cut, feed rate and laser-to-cutting tool distance. From the result, the effectiveness of laser assisted and cutting parameter in term of cutting force and tool wear was identified by comparing between conventional and LAMM. Finally, the optimum range of machining parameters can be determined.

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.

Research on the Influence Factors for the Deflection of Micro-Ball-End Cutter in Micro-End-Milling Process

2011 ◽  
Vol 697-698 ◽  
pp. 84-87 ◽  
Author(s):  
Ming Jun Chen ◽  
Zhi Jun Wang ◽  
Chun Ya Wu ◽  
Hai Bo Ni
Keyword(s):  
End Milling ◽  
Three Dimensional ◽  
Great Influence ◽  
Milling Process ◽  
Micro Milling ◽  
Machining Parameters ◽  
Cutting Depth ◽  
Cutter Deflection ◽  
Micro End Milling ◽  
End Milling Process

Machining parameters and spindle radial runout have great influence on the micro-ball-end cutter deflection in the micro-end-milling process. In this study, a 3D (three-dimensional) thermal-mechanical FEM (finite element method) model of micro-milling with non-rigid cutter is built to study how radial runout, cutting depth, feed and spindle speed influence the cutter deflection when feed has the same direction with the spindle radial runout. Cutter deflection under different groove lengths, cutting depths, feeds and spindle speeds is investigated, which shows that cutter deflection increases with spindle radial runout significantly. The largest deflections with runout of 2μm are 3.26μm, 3.26μm, 4.71μm and 4.52μm respectively under the adopted machining conditions, while the largest deflections without runout are 1.85μm, 1.85μm, 2.26μm and 3.79μm respectively. It is also shown that the runout effect increases with groove length, cutting depth, while it decreases with feed.

scholarly journals Analysis of Burr Formation in Low Speed Micro-milling of Titanium Alloy (Ti-6Al-4V)

2018 ◽  
Vol 9 (2) ◽  
pp. 231-243 ◽  
Author(s):  
Gulfam Ul Rehman ◽  
Syed Husain Imran Jaffery ◽  
Mushtaq Khan ◽  
Liaqat Ali ◽  
Ashfaq Khan ◽  
...  
Keyword(s):  
High Speed ◽  
Cutting Speed ◽  
Statistical Technique ◽  
Micro Milling ◽  
Burr Formation ◽  
Dominant Factor ◽  
Depth Of Cut ◽  
Optimum Process ◽  
Machining Parameters ◽  
Low Speed

Abstract. The use of titanium based alloys in aerospace and biomedical applications make them an attractive choice for research in micro-machining. In this research, low speed micro-milling is used to analyze machinability of Ti-6Al-4V alloy as low speed machining setup is not expensive and it can be carried out on conventional machine tools already available at most machining setups. Parameters like feed per tooth, cutting speed and depth of cut are selected as machining variables and their effect on burr formation is analyzed through statistical technique analysis of variance to determine key process variables. Results show that feed per tooth is the most dominant factor in burr formation (81 % contribution ratio). The effect of depth of cut was found to be negligible. It was also observed that micro-milling at optimum process parameters showed minimum burr formation. In terms of burr formation, as compared to high speed machining setup, better results were achieved at low speed machining setup by varying machining parameters.

Micro-Machinability Studies of Single Crystal Silicon Using Diamond End-Mill

2016 ◽  
Author(s):  
Zi Jie Choong ◽  
Dehong Huo ◽  
Patrick Degenaar ◽  
Anthony O’Neill
Keyword(s):  
Size Effect ◽  
Single Crystal Silicon ◽  
Micro Milling ◽  
Depth Of Cut ◽  
Machining Parameters ◽  
Specific Cutting Energy ◽  
Crystal Silicon ◽  
Edge Chipping ◽  
Cutting Energy ◽  
Machining Conditions

This paper presents the research on the machinability studies in micro-milling of (001) silicon wafer. Excessive generation of undesirable surface and subsurface damages such as surface edge chipping often occurs when machined at depth of cut of several hundreds of microns. Ideal machining strategy to reduce the generation of edge chipping is required. Investigations on the effect of machining conditions on the cutting performances and size effect on the specific cutting energy in silicon micro-milling were conducted. These investigations provide understandings on the behavior of cutting mechanism during machining and helps to identify suitable machining parameters for fracture free machining using diamond end mills. Full slot milling were performed along <100> and <110> directions on a (001) surface wafer under various machining conditions. Results show that machined surfaces along <100> were of better quality than those along <110> and is in agreement with previous studies. Furthermore, good machining quality was achieved when machined at depth of cut of 10 μm or feed per tooth of 0.075 μm/tooth, regardless of the machining conditions. In addition, investigation for the size effect on specific cutting energy also shows that brittle mode machining begins when feed per tooth increases beyond 0.4 μm/tooth.

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.

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