scholarly journals Microdrilling of Biocompatible Materials

2012 ◽  
Author(s):  
Sankalp Mohanty ◽  
Stephen Wells ◽  
Wayne Hung
Keyword(s):  
Stainless Steel ◽  
Aspect Ratio ◽  
Tool Life ◽  
316L Stainless Steel ◽  
Pure Titanium ◽  
Cutting Speed ◽  
Hole Quality ◽  
Tool Failure ◽  
Drilling Parameters ◽  
Tool Performance

Product miniaturization trend is inevitable. The needs for minimum invasive surgery, smaller sensors for smart machinery, packing more features on a product… require mass production of smaller components from engineering materials. Fabrication of microcomponents requires knowledge of micromachining to avoid costly tool failure and part damage. This research investigates microdrilling of commercially pure titanium, nickel titanium (Nitinol), and 316L stainless steel. A surface was polished and drilled in rows of ten holes. Through hole drilling at 6:1 aspect ratio was performed on NiTi sheets while blind holes were drilled at 10:1 aspect ratio on Ti or 316L blocks. Microdrills with 100–150 μm diameter and 1.5–3.5 mm flute length were utilized up to 50,000 rpm in minimum quantity lubrication. Finite element models were developed to find upper limits of drilling parameters. Flank wear of 15μm on fine grained WC-Co uncoated tools and peeling of coating layer were used as tool life criteria. Scanning electron microscopy was used to observed tool failure mechanism. Tool life modeling and hole quality were performed to evaluate and compare tool performance. Although successfully drilling all materials at 10:1 aspect ratio, excessive built-up-edge (BUE) was found on microdrills at all drilling parameters. Such BUE effectively blunted the drill tips and caused drill wandering, degraded hole quality due to rubbing against the drilled wall, work-hardened the drilled surface and accelerated drill wear, and formed burrs at both entrance and exit ends. Wear of a microdrill at the outer corner was more pronounced when drilling CP titanium, but attrition wear at chisel edge was more significant for 316L stainless steel. The classical Taylor equation for macromachining was applicable in microdrilling to rank tool performance and machinability of tested materials. For the same cutting speed of 20 m/min and comparable drilling distance of about 35 mm, CP titanium can be microdrilled 400% faster than 316L stainless steel when applying 0.1 μm/flute chip load for the former and 0.02 μm/flute for the latter. The AlTiN coated drills improved tool life by at least 120%. This coating reduced BUE, drastically improved hole position accuracy by 115%, and decreased hole diameter variation from 0.110% to 0.003% for each mm of drilling distance.

Model for Optimization of the Tool Life and the Cutting Speed for Maximum Productivity at Drilling of the Steel 2NiCr185

2015 ◽  
Vol 760 ◽  
pp. 433-438 ◽  
Author(s):  
Ovidiu Blăjină ◽  
Aurelian Vlase ◽  
Marius Iacob
Keyword(s):  
Mathematical Model ◽  
Stainless Steel ◽  
Tool Life ◽  
Stainless Steels ◽  
Cutting Tool ◽  
Cutting Speed ◽  
Research Directions ◽  
Maximum Productivity ◽  
Optimum Cutting ◽  
New Research

The research in the last decade regarding their cutting machinability have highlighted the insufficiency of the data for establishing of the optimum cutting processing conditions and the optimum cutting regime. The purpose of this paper is the optimization of the tool life and the cutting speed at the drilling of the stainless steels in terms of the maximum productivity. A nonlinear programming mathematical model to maximize the productivity at the drilling of a stainless steel is developed in this paper. The optimum cutting tool life and the associated cutting tool speed are obtained by solving the proposed mathematical model. The use of this productivity model allows greater accuracy in the prediction of the productivity for the drilling of a certain stainless steel and getting the optimum tool life and the optimum cutting speed for the maximum productivity. The obtained results can be used in production activity, in order to increase the productivity of the stainless steels machining. Finally the paper suggests new research directions for the specialists interested in this field.

Optimum Tool Life and Cutting Speed for the Maximum Productivity at the Drilling of the Steel X6CrNiTi18-10

2013 ◽  
Vol 837 ◽  
pp. 28-32
Author(s):  
Ovidiu Blăjină ◽  
Aurelian Vlase ◽  
Vlad Darie
Keyword(s):  
Stainless Steel ◽  
Tool Life ◽  
Stainless Steels ◽  
Cutting Tool ◽  
Programming Model ◽  
Cutting Speed ◽  
Maximum Productivity ◽  
Optimum Cutting ◽  
Nonlinear Programming Model ◽  
New Research

The research in the last decade regarding their cutting machinability have highlighted the insufficiency of the data for establishing of the optimum cutting processing conditions and the optimum cutting regime. The purpose of this paper is the optimization of the tool life and the cutting speed at the drilling of the stainless steels in terms of the maximum productivity. A nonlinear programming model to maximize the productivity at the drilling of a stainless steel is developed in this paper. The optimum cutting tool life and the associated cutting tool speed are obtained by solving the proposed mathematical model. The use of this productivity model allows greater accuracy in the prediction of the productivity for the drilling of a certain stainless steel and getting the optimum tool life and the optimum cutting speed for the maximum productivity. The obtained results can be used in production activity, in order to increase the productivity of the stainless steels machining. Finally the paper suggests new research directions for the specialists interested in this field.

scholarly journals Threading Performance of Different Coatings for High Speed Steel Tapping

Coatings ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 464
Author(s):  
Alain Gil Del Val ◽  
Fernando Veiga ◽  
Octavio Pereira ◽  
Luis Norberto Lopez De Lacalle
Keyword(s):  
Tool Life ◽  
Vapor Deposition ◽  
Physical Vapor Deposition ◽  
High Speed ◽  
Cutting Speed ◽  
High Speed Steel ◽  
Tialn Coating ◽  
Tool Performance ◽  
Thread Profile ◽  
Increase Tool Life

Threading holes using tapping tools is a widely used machining operation in the industry. This manufacturing process involves a great tool immersion in the part, which involves both friction and cutting. This makes the use of coatings critical to improving tool life. Four coatings are used based on Physical vapor deposition (PVD) technology—TiN, TiCN, TiAlN and TiAlN+WC/C are compared to uncoated tool performance. The effect of various coatings on the life of M12 × 1.5 tapping tools during threading of through holes 20 mm deep, in GG25 casting plates, dry and applying cutting speed of 50 m/min. The end-of-life criterion has been established based on a cutting torque of 16 N-m. Taking the uncoated tap as a basis for comparison, it is observed that coatings based on PVD technologies increase tool life doubling in the most advantageous case with the TiAlN coating. PVD type coatings provide better protection to wear at cylindrical area of the tool, where the thread profile is finished, than uncoated taps. The teeth located in the cone-cylinder transition zone of the taps suffer the most wear regardless of the coating. However, taps coated with TiAlN+WC/C wear level values is lowest of all the coatings tested, which indicates a strong reinforcement in these teeth.

The Effect of Tool Edge Geometry on Tool Performance and Surface Integrity in Turning Ti-6Al-4V Alloys

2011 ◽  
Vol 264-265 ◽  
pp. 1211-1221 ◽  
Author(s):  
Yanuar Burhanuddin ◽  
Che Hassan Che Haron ◽  
Jaharah A. Ghani
Keyword(s):  
Tool Life ◽  
Surface Integrity ◽  
Feed Rate ◽  
Cutting Speed ◽  
Optical Microscope ◽  
Edge Geometry ◽  
Tool Performance ◽  
Tool Edge ◽  
Structural Deformations ◽  
Notch Wear

This paper focuses on the influence of cutting tool edge geometry, cutting speed and feed rate on the tool performance and workpiece’s surface integrity in dry turning of Ti-6Al-4V alloy using PCBN inserts. The parameters evaluated are tool life, wear rate, wear mechanisms, surface roughness and subsurface microstructure alterations. The rate of wear growth of the insert was assessed by progressive flank wear using optical microscope by taking photographs after certain length of cut. The wear mechanism at the end of tool life was investigated in detail using scanning electron microscope (SEM) and EDAX analysis. The results show, by increasing the cutting speed and feed rate resulted in tool life reduction. Cutting with honed edge insert at cutting speed of 180 m/min has shown very little wear, even after 20 min of cutting. The honed insert proved less sensitive to increases in feed rate than the chamfered insert. In general the honed insert showed a significant improvement in tool life. All inserts failed due to attrition wear and adhesion. No flank notch wear was observed, but some crater wear occurred at the chamfer land. Microstructure alteration was not found when machining using the different edge geometry. In these trials, the subsurface micro structural deformations in the direction of cutting were deformed grain boundaries and elongation of grains. Chip smearing and debris on the surface was also found.

Experimental Study on Nano-TiAlN Coated Carbide Tools in Turning Austenitic Stainless Steel

2012 ◽  
Vol 723 ◽  
pp. 247-251
Author(s):  
Hai Dong Yang ◽  
Zhi Ding
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Tool Life ◽  
Cutting Speed ◽  
Cutting Parameters ◽  
Dry Cutting ◽  
Processing Efficiency ◽  
Machined Surface ◽  
Tool Wear Mechanism ◽  
Coated Carbide

Austenitic stainless steel has poor cutting performance, especially when the inappropriate choice of tool materials and cutting parameters, cutting tool life will be shortened and the quality of machined surface is poor. In this paper, 0Cr18Ni9 stainless steel dry cutting tests had been done with nano-TiAlN coated carbide blade YGB202, the relationship between tool life and cutting speed, tool wear mechanism had been analyzed. In order to improve the processing efficiency and tool life, process parameters were optimized.

Machining parameters effect in dry turning of AISI 316L stainless steel using coated carbide tools

2015 ◽  
Vol 231 (4) ◽  
pp. 676-683 ◽  
Author(s):  
Rusdi Nur ◽  
MY Noordin ◽  
S Izman ◽  
D Kurniawan
Keyword(s):  
Surface Roughness ◽  
Stainless Steel ◽  
Power Consumption ◽  
Cutting Force ◽  
Tool Life ◽  
Cutting Speed ◽  
Cutting Fluid ◽  
Machining Parameters ◽  
Aisi 316L ◽  
Coated Carbide

Austenitic stainless steel AISI 316L is used in many applications, including chemical industry, nuclear power plants, and medical devices, because of its high mechanical properties and corrosion resistance. Machinability study on the stainless steel is of interest. Toward sustainable manufacturing, this study also includes the power consumption during machining along with other machining responses of cutting force, surface roughness, and tool life. Turning on the stainless steel was performed using coated carbide tool without using cutting fluid. The turning was performed at various cutting speeds (90, 150, and 210 m/min) and feeds (0.10, 0.16, and 0.22 mm/rev). Response surface methodology was adopted in designing the experiments to quantify the effect of cutting speed and feed on the machining responses. It was found that cutting speed was proportional to power consumption and was inversely proportional to tool life, and showed no significant effect on the cutting force and the surface roughness. Feed was proportional to cutting force, power consumption, and surface roughness and was inversely proportional to tool life. Empirical equations developed from the results for all machining responses were shown to be useful in determining the optimum cutting parameters range.

Tool wear morphology and life under various lubrication modes in turning stainless steel 316L

2020 ◽  
Vol 44 (3) ◽  
pp. 352-361 ◽  
Author(s):  
Nader Barari ◽  
Seyed Ali Niknam ◽  
Hedayeh Mehmanparast
Keyword(s):  
Stainless Steel ◽  
Tool Wear ◽  
Tool Life ◽  
Gas Turbines ◽  
316L Stainless Steel ◽  
Cutting Tools ◽  
Industrial Applications ◽  
Mechanical And Thermal Properties ◽  
Machining Performance ◽  
Stainless Steel 316L

One of the most important industrial demands is to improve the machinability of hard steels. Among hard steels, 316L stainless steel has significant mechanical and thermal properties recommended for many industrial applications and products, including aero-engines and gas turbines. Similar to many other hard-to-cut materials, the machining of 316L stainless steel requires an adequate selection of cutting parameters and lubrication modes. Limited studies have been found in this regard. In the present study, turning tests were conducted on 316L steel and the tool wear magnitude and morphology were assessed under four lubrication modes. Furthermore, to improve machining performance, a minimum quantity lubrication (MQL) system was used and the obtained results under this lubrication mode were compared to three other types of lubrication modes, including dry, wet, and MQCL. The composition of the adhered material on the cutting tools shows that in all lubrication modes, built-up edge (BUE) occurred. Furthermore, the use of high pressure-lubricated machining (MQCL) led to longer tool life as compared to the other three lubrication modes used. In fact, double the tool life was recorded for the cutting tools used under the MQCL mode.

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.

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