Evaluation of the Performance of Micro-Drills in Drilling a Machinable Ceramic Material

2014 ◽  
Vol 619 ◽  
pp. 49-53
Author(s):  
Hyun Ho Shin ◽  
In Joon Hwang ◽  
Sung Jun Lim ◽  
Bum Sup Kim
Keyword(s):  
Ceramic Material ◽  
Rotation Rate ◽  
Critical Speed ◽  
Rear Side ◽  
Boundary Line ◽  
Feed Speed ◽  
Drilling Performance ◽  
Critical Boundary ◽  
Machinable Ceramic ◽  
Micro Drill

The performance of three different micro-drills in drilling a machinable ceramic material has been evaluated in terms of the critical feed speed (mm/min) at a given rotation rate (rpm). The critical speed is the feed speed from and above which the chipping on the rear side of the machinable ceramic material takes place. The determined critical speed turns out to increase with rotation rate in the tested range of 2k-8k rpm, forming the critical boundary line. The drilling performance of the micro-drills can be evaluated quantitatively by using the position of the critical boundary lines in the space of feed speed vs. rotation rate: the upper the critical boundary line, the higher the drilling performance of the micro-drill.

Drilling performance of non-coaxial helical flank micro-drill with cross-shaped chisel edge

2018 ◽  
Vol 99 (5-8) ◽  
pp. 1301-1311 ◽  
Author(s):  
Haixin Guo ◽  
Xibin Wang ◽  
Zhiqiang Liang ◽  
Tianfeng Zhou ◽  
Li Jiao ◽  
...  
Keyword(s):  
Drilling Performance ◽  
Micro Drill

Influence of Drill Geometry Parameters on Helical Point Micro Drilling Performance

2016 ◽  
Vol 836-837 ◽  
pp. 198-204
Author(s):  
Su Yan Zhang ◽  
Zhi Qiang Liang ◽  
Xi Bin Wang ◽  
Tian Feng Zhou ◽  
Pei Yan ◽  
...  
Keyword(s):  
Thrust Force ◽  
Helix Angle ◽  
Contributory Factor ◽  
Drilling Performance ◽  
Micro Drilling ◽  
Moderate Effect ◽  
Drill Point ◽  
Micro Drill ◽  
Selection Of ◽  
Small Point

Helical point micro-drill is characterized by a continuous helical flank instead of the piecewise planar flank, and its improved drilling performance is validated compared with planar drill point by some researchers. In this study, to analyze the effect of geometry parameters of helical point drill on the drilling performance, the micro-drills with different point angles, web thicknesses and helix angles of the flute are fabricated on a 6-axis CNC tool grinder, and a serial of micro-drilling experiments involving these drills on 1Cr18Ni9Ti austenitic stainless steel are carried out. In experiments, the drilling forces are measured and exit burrs are observed. Within a certain range of geometry parameters, thrust force increases with the increase of point angle and web thickness, and the decrease of the helix angle of the flute. The point angle is the main contributory factor for the thrust force followed by web thickness, while helix angle has a moderate effect on the force. Furthermore, poisson burr and rollover burr are generated with different point angles. Based on the results, a good selection of the helical point drill geometry parameters with small point angle, big helix angle and small web thickness are proposed to improve the micro-drilling performance.

Mathematical Model and Simulation of Regrind Chisel Edge for Helical Micro-Drill

2006 ◽  
Vol 304-305 ◽  
pp. 550-554 ◽  
Author(s):  
W.J. Xiang ◽  
Zhi Xiong Zhou ◽  
S.J. Hu ◽  
J. Yang ◽  
J.P. Liang
Keyword(s):  
Mathematical Model ◽  
Geometric Model ◽  
Drilling Performance ◽  
Model And Simulation ◽  
Kinematic Relationship ◽  
Micro Drilling ◽  
Novel Method ◽  
Relationship Of ◽  
Micro Drill ◽  
Easy Operation

Micro-drills are becoming more and more important in precision and micro fabrications. They have been widely used in applications, e.g., precision and micro drilling. In this paper, a novel method is advanced and used for regrinding of chisel edges of helical micro-drills. In this method, a geometric model is established for the chisel edge regrinding. Based on the kinematic relationship of regrinding, the model simplifies machine movement so as to facilitate an easy operation. Computer simulation is applied to the regrinding process of the micro-drills. The results demonstrate that the proposed method is effective in regrinding chisel edges, which allows for a more reasonable distribution of the angles along the chisel edge of a drill, and enhances the drilling performance.

A 5-Axis Coordinated CNC Grinding Method for the Flank of a Non-Coaxial Helical Micro-Drill with the Cylinder Grinding Wheel

2014 ◽  
Vol 1017 ◽  
pp. 654-659 ◽  
Author(s):  
Zhi Qiang Liang ◽  
Hong Chao Jian ◽  
Xi Bin Wang ◽  
Wen Xiang Zhao ◽  
Su Yan Zhang ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Grinding Wheel ◽  
Three Dimension ◽  
Drilling Performance ◽  
Grinding Method ◽  
Cnc Grinding ◽  
Micro Drilling ◽  
Drill Point ◽  
Micro Drill ◽  
Drill Tool

Micro-drilling become more widely used from precision mechanics to electronics. Nowadays, the main commercial tools are planar point micro-drills. However, that geometry often causes a high thrust force, high temperature, and rapid wear during micro-drilling. Furthermore, it is difficult to adjust the four flank surfaces to accurately intersect at one point, particularly when the drill diameter becomes smaller. To solve this problem, non-coaxial helical drills points have been proposed by some researchers, and is characterized by a continuous helical flank instead of the piecewise planar flank. Its drilling performance is improved compared with planar drill point. This study presents a 5-axis coordinated CNC grinding method of the non-coaxial helical drill flank. Mathematical models of the drill flank and its engagement line between cylinder grinding wheel and drill tool are established, and then the path of the grinding wheel with respect to the drill tool is obtained. In order to verify the availability of the proposed methods, three dimension (3D) grinding simulation of non-coaxial helical drills with diameter 0.5mm was carried out using the CAD software, and then were fabricated on a 6-axis Makino CNC tool grinder. The ground micro-drills examined by 3D laser scanning microscope show good identity with the simulated result. These indicate that the manufacturing model presented in this paper provides a practical and efficient method to grind the flank of a non-coaxial helical micro-drill.

Influence of chisel edge axial rake angle on the drilling performance of helical point micro-drill

2020 ◽  
Vol 107 (5-6) ◽  
pp. 2137-2149
Author(s):  
Zhiqiang Liang ◽  
Haixin Guo ◽  
Xibin Wang ◽  
Yue Ma ◽  
Tianfeng Zhou ◽  
...  
Keyword(s):  
Rake Angle ◽  
Drilling Performance ◽  
Micro Drill

scholarly journals Investigation on Surface Insulation Strength of Machinable Ceramic Material under Pulsed Voltage in Vacuum

Shinku ◽  
2007 ◽  
Vol 50 (5) ◽  
pp. 332-336 ◽  
Author(s):  
Guan-Jun ZHANG ◽  
Wen-Bin ZHAO ◽  
Xin-Pei MA ◽  
Guang-Xin LI ◽  
Kui MA ◽  
...  
Keyword(s):  
Ceramic Material ◽  
Machinable Ceramic ◽  
Pulsed Voltage

The Study of High Speed Micro-Drilling Performance and Machining Quality of Coated Micro-Drills with Zr-C:H Coatings

2012 ◽  
Vol 591-593 ◽  
pp. 342-346 ◽  
Author(s):  
Wen Hsien Kao ◽  
Yan Liang Su ◽  
Sun Hui Yao ◽  
H.C. Huang ◽  
M.S. Chen
Keyword(s):  
High Speed ◽  
Printed Circuit Board ◽  
Circuit Board ◽  
Hole Drilling ◽  
Closed Field ◽  
Machining Performance ◽  
Machining Quality ◽  
Drilling Performance ◽  
Micro Drilling ◽  
Micro Drill

The Zr-C:H coatings with various C2H2 flow rate were deposited on micro-drills (a diameter of 0.2 mm) used a closed field unbalanced magnetron sputtering system. The ultrahigh speed (drilling speed of 160000 rpm) through-hole drilling printed circuit board tests used to evaluate the drilling performance of the coated micro-drills. The rejection criteria of service lives of the coated micro-drills were evaluated using two different criteria: (1) a nail head ratio greater than 1.5; (2) a drilled hole surface roughness greater than 25.4 μm. Adopting a service life criterion of a nail head ratio of 1.5, the Zr-C:H-5 coating possesses the optimal high-speed machining performance, which yields a micro-drill lifetime of above 6000 drilled holes. It represents a three-fold improvement on that of an uncoated micro-drill and it also improves machining quality.

Influence of Wheel Position Parameters on Flute Profile of Micro-Drill

2016 ◽  
Vol 874 ◽  
pp. 52-58 ◽  
Author(s):  
Su Yan Zhang ◽  
Zhi Qiang Liang ◽  
Xi Bin Wang ◽  
Tian Feng Zhou ◽  
Li Jiao ◽  
...  
Keyword(s):  
Great Influence ◽  
Rake Angle ◽  
Obvious Effect ◽  
Drilling Performance ◽  
Installation Angle ◽  
Offset Distance ◽  
Radial Rake Angle ◽  
Wheel Profile ◽  
On Chip ◽  
Micro Drill

Drill flute has a great influence on the drilling performance of micro-drill, and its profile largely depends on the grinding parameters, wheel profile and position. It is promising to obtain a desired flute profile with a standard wheel by adjusting the wheel position parameters. To investigate the influence of wheel position parameters on the flute profile, the micro-drill flute is simulated by MATLAB software considering the wheel installation angle and the offset distance from wheel origin to the drill blank origin, and the radial rake angle, flute width and chip evacuation capacity are quantitatively calculated to evaluate the flute profile. The simulated results show that the wheel installation angle has an obvious effect on the three performance parameters of flute profile, and the wheel offset distance only influences a parameter, i.e., the flute width evidently. The radial rake angle of drill flute increases obviously with the increased wheel installation angle, and decreases slightly with the increased wheel offset distance. With the decreased wheel installation angle, the flute width of drill flute increases causing the reduction of micro-drill strength but improvement of the chip evacuation capacity. With the increased wheel offset distance, the flute width also increases resulting in the reduction of micro-drill strength but no obvious change on chip evacuation capacity. Thus the wheel installation angle can be used as a main factor among the wheel position parameters to obtain the desired flute profile.

Improvement in Drilling Performance of Micro Compound Tool

2010 ◽  
Vol 447-448 ◽  
pp. 96-100
Author(s):  
Osamu Ohnishi ◽  
Hiromichi Onikura ◽  
Toshihiko Eguchi ◽  
Muhammad Aziz ◽  
Toshiro K. Doi ◽  
...  
Keyword(s):  
Ultrasonic Vibration ◽  
Small Difference ◽  
Burr Formation ◽  
Diamond Grit ◽  
Part Geometry ◽  
Drilling Performance ◽  
Large Size ◽  
Micro Drilling ◽  
Micro Drill ◽  
Secondary Cutting

The present paper deals with the development of micro compound tools and their application to the micro drilling. The micro compound tool consists of a micro drill part and an electroplated part with a nominal finishing diameter of 100 µm and they are fabricated by grinding and electroplating processes. Fabricated tools are used in drilling tests with or without ultrasonic vibration. Influences of drill part geometry on burr formation and influences of diamond grit size on peeling of the electroplating layer are investigated. As the results, secondary cutting edges do not seem to have remarkable ability for reduction of burrs. And large size of diamond grit at the electroplated part of a micro compound tool with a small difference between a diameter of electroplated part and a diameter of drill part seems to be effective in preventing peeling of the electroplating layer and improving drilling performance.

Sign in / Sign up

Export Citation Format

Share Document