A Study of the Drilling Process

1974 ◽  
Vol 96 (4) ◽  
pp. 1207-1215 ◽  
Author(s):  
R. A. Williams
Keyword(s):  
Feed Rate ◽  
Thrust Force ◽  
Three Dimensional ◽  
Drilling Process ◽  
Two Dimensional ◽  
Twist Drill ◽  
Feed Velocity ◽  
Cutting Geometry ◽  
Drill Point ◽  
Finite Thrust

Drilling is a complex three dimensional cutting process yet it is possible to simulate the action of a two flute twist drill with two dimensional models provided consideration is given to the influence of the feed velocity on the cutting geometry at the drill point. Two models of chip formation and an indentation model are developed to simulate the action of the drill point. From these models equations are derived for the prediction of total torque and thrust given the cutting conditions, drill geometry, and an empirical factor which is related to the work material. Computed values of torque and thrust are shown to compare favorably with those obtained from drilling tests on an 0.45 percent C steel. The shape and magnitude of the wear zone about the chisel edge is estimated and it is shown that the observed finite thrust force as the feed rate approaches zero can be attributed to the “cutting” action of the chisel edge.

Effects of Twist Drill Point Angle on Thrust Force and Delamination Factor in Hybrid Fiber Composites Drilling

2014 ◽  
Vol 564 ◽  
pp. 501-506 ◽  
Author(s):  
Mohd Azuwan Maoinser ◽  
Faiz Ahmad ◽  
Safian Shariff ◽  
Tze Keong Woo
Keyword(s):  
Feed Rate ◽  
Thrust Force ◽  
Polymeric Composite ◽  
Drilling Process ◽  
Twist Drill ◽  
Fiber Reinforced ◽  
Hybrid Fiber ◽  
Frp Composites ◽  
Delamination Factor ◽  
Drill Point

Drill point angle of twist drill has a significant effect on thrust force and delamination factor on drilled holes in fiber reinforced polymer (FRP) composites. In this study, three drill point angle of twist drill; 85°, 118° and 135° were used to drill holes in hybrid fiber reinforced polymeric composite (HFRP). HFRP composites were fabricated using vacuum infusion molding (VIM) technique. The test samples were cured at 90°C for two hours. In drilling process various drill point angle and feed rate were employed to investigate the effect of both parameters on thrust force and delamination factor when drilling the HFRP composite. The results showed that small drill point angle and low feed rate can reduce the thrust force leading to the reduction of damage factor at the holes entrance and exit.

Effect of Periodic Drilling Force on Instability in a Drilling Process

2005 ◽  
Vol 219 (8) ◽  
pp. 733-742 ◽  
Author(s):  
B W Huang ◽  
H K Kung ◽  
A W L Yao
Keyword(s):  
Numerical Analysis ◽  
Thrust Force ◽  
Dynamic Instability ◽  
Drilling Process ◽  
Twist Drill ◽  
Unstable Condition ◽  
Drilling Force ◽  
Cutting Geometry ◽  
Drilling Quality ◽  
Spinning Speed

The periodic drilling force effect on the dynamic instability of a drill in a drilling process was investigated. This investigation involves the cutting geometry drilling force from the two active parts of a twist drill subjected to small fluctuations during the drilling process. Theoretically, at some drilling force, this small drilling force fluctuation may lead the system into a dynamically unstable condition. Most hole location errors, reaming, and drill fractures occur in this unstable drilling process phase. The dynamic instability in a drilling process is an important issue in increasing the drilling quality and production rate. In this article, a pretwisted beam with a moving Winkler-type elastic foundation is used to simulate the drill and drilling process. Numerical analysis indicates that the unstable regions are enlarged and shifted to a lower frequency suddenly as the drill bites into a workpiece. It is also observed that the thrust force, spinning speed, and pretwisted angle effects drastically change the dynamic instability of drilling.

scholarly journals Effect of Twist Drill Geometry and Drilling Parameters on Hole Quality in Single-Shot Drilling of CFRP/Al7075-T6 Composite Stack

2021 ◽  
Vol 5 (7) ◽  
pp. 189
Author(s):  
Muhammad Hafiz Hassan ◽  
Jamaluddin Abdullah ◽  
Gérald Franz ◽  
Chim Yi Shen ◽  
Reza Mahmoodian
Keyword(s):  
Feed Rate ◽  
Thrust Force ◽  
Critical Dimension ◽  
Helix Angle ◽  
Single Shot ◽  
Twist Drill ◽  
Hole Quality ◽  
Drilling Parameters ◽  
Industry Practice ◽  
Maximum Thrust

Drilling two different materials in a layer, or stack-up, is being practiced widely in the aerospace industry to minimize critical dimension mismatch and error in the subsequent assembly process, but the compatibility of the drill to compensate the widely differing properties of composite is still a major challenge to the industry. In this paper, the effect of customized twist drill geometry and drilling parameters are being investigated based on the thrust force signature generated during the drilling of CFRP/Al7075-T6. Based on ANOVA, it is found that the maximum thrust force for both CFRP and Al7075-T6 are highly dependent on the feed rate. Through the analysis of maximum thrust force, supported by hole diameter error, hole surface roughness, and chip formation, it is found that the optimum tool parameters selection includes a helix angle of 30°, primary clearance angle of 6°, point angle of 130°, chisel edge angle of 30°, speed of 2600 rev/min and feed rate of 0.05 mm/rev. The optimum parameters obtained in this study are benchmarked against existing industry practice of the capability to produce higher hole quality and efficiency, which is set at 2600 rev/min for speed and 0.1 mm/rev for feed rate.

scholarly journals Effect of Cutting Parameters and Tool Geometry on the Performance Analysis of One-Shot Drilling Process of AA2024-T3

Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 854
Author(s):  
Muhammad Aamir ◽  
Khaled Giasin ◽  
Majid Tolouei-Rad ◽  
Israr Ud Din ◽  
Muhammad Imran Hanif ◽  
...  
Keyword(s):  
Feed Rate ◽  
Surface Defects ◽  
Thrust Force ◽  
Cutting Tools ◽  
Chip Thickness ◽  
Cutting Parameters ◽  
Spindle Speed ◽  
Machining Process ◽  
Tool Geometry ◽  
Drilling Process

Drilling is an important machining process in various manufacturing industries. High-quality holes are possible with the proper selection of tools and cutting parameters. This study investigates the effect of spindle speed, feed rate, and drill diameter on the generated thrust force, the formation of chips, post-machining tool condition, and hole quality. The hole surface defects and the top and bottom edge conditions were also investigated using scan electron microscopy. The drilling tests were carried out on AA2024-T3 alloy under a dry drilling environment using 6 and 10 mm uncoated carbide tools. Analysis of Variance was employed to further evaluate the influence of the input parameters on the analysed outputs. The results show that the thrust force was highly influenced by feed rate and drill size. The high spindle speed resulted in higher surface roughness, while the increase in the feed rate produced more burrs around the edges of the holes. Additionally, the burrs formed at the exit side of holes were larger than those formed at the entry side. The high drill size resulted in greater chip thickness and an increased built-up edge on the cutting tools.

Experiments of Drilling Titanium Alloy with Varying Operation Parameters

2017 ◽  
Vol 748 ◽  
pp. 254-258
Author(s):  
Chang Yi Liu ◽  
Bai Shou Zhang ◽  
Suman Shrestha
Keyword(s):  
Titanium Alloy ◽  
Feed Rate ◽  
Thrust Force ◽  
Maximum Amount ◽  
Spindle Speed ◽  
Drilling Process ◽  
Process Variables ◽  
Experimental Cutting ◽  
Operation Parameters ◽  
Titanium Alloy Ti6al4v

Drilling experiments of titanium alloy Ti6Al4V were conducted. Taking the speed and feed as the process variables, a set of experimental cutting forces are obtained and compared. From the experimental results it is concluded that within the experimental extent the thrust force and torque of drilling process rises with the feed rate. The lower spindle speed resulted in the greater amount of thrust. Feed rates have greater influence on the thrust force than the spindle speed. The combination of greater feed rate and lower spindle speed results in the maximum amount of thrust. However, combination of greater feed rate and spindle speed resulted in maximum amount of torque.

Monitoring of hole surface integrity in drilling of bi-directional woven carbon fiber reinforced plastic composites

2020 ◽  
Vol 234 (12) ◽  
pp. 2432-2458 ◽  
Author(s):  
Tarakeswar Barik ◽  
Kamal Pal ◽  
Smruti Parimita ◽  
Priyabrata Sahoo ◽  
Karali Patra
Keyword(s):  
Carbon Fiber ◽  
Feed Rate ◽  
Thrust Force ◽  
Internal Surface ◽  
Carbon Fiber Reinforced Plastic ◽  
Fiber Reinforced ◽  
Fiber Reinforced Plastic ◽  
Reinforced Plastic ◽  
Circularity Error ◽  
Drill Point

Fiber-reinforced plastic is one of the top priorities lightweight materials with excellent mechanical properties for the aerospace industries in recent years. However, it is difficult to machine despite having unique properties due to its non-homogeneous and abrasive nature in alternate fiber and matrix layers. Thus, it is found to be a challenging task to drill hole on such hard-to-machine materials, which is highly essential for the development of most of the engineering structural components. The present work addresses various drilling-induced defects such as delamination, circularity error, and roughness variations in the hole surface during drilling of quasi-isotropic cross-fiber oriented bi-directional woven-type carbon fiber reinforced plastic laminate using a full factorial design of experiments for different drill geometry. The response surface methodology was considered for the regression model development, which was found to be highly significant. The machining forces with associated torque have also been acquired during drilling, which was divided and further analyzed in time domain to correlate with drilling flaws. The drilling-induced delamination was found to be higher at a high feed rate using a higher drill point angle due to substantial thrust force generation at the initial stages in the drilling cycle. However, the internal surface finish with associated circularity error was reduced for higher spindle speed with less feed rate using a low drill point angle because of low torque fluctuation at the final drilling phases. The axial thrust force was found to be a prime indicator of drilled hole surface delamination, whereas drilling torque precisely indicated internal surface roughness as well as circularity error. The global root mean square, along with a local peak of thrust and torque, both were highly essential to completely characterize the drilled hole quality.

Drilling Force and Chip Morphology in Drilling of PCB Supported Hole

2011 ◽  
Vol 188 ◽  
pp. 429-434 ◽  
Author(s):  
L.P. Yang ◽  
Li Xin Huang ◽  
Cheng Yong Wang ◽  
L.J. Zheng ◽  
Ping Ma ◽  
...  
Keyword(s):  
Feed Rate ◽  
Printed Circuit Board ◽  
Thrust Force ◽  
Chip Morphology ◽  
Cutting Parameters ◽  
Spindle Speed ◽  
Circuit Board ◽  
Drilling Process ◽  
Drilling Force ◽  
Drill Bits

Supported holes of Printed circuit board (PCB) are drilled with two different drill bits. Drilling force (thrust force and torque) and chip morphology are examined at different cutting parameters, and the effects of the two drills are discussed. The results indicate that the drilling force and chip morphology are affected by the feed rate, spindle speed and drill shape. Thrust force increases with the increasing feed rate, and decreases with the increasing spindle speed. Optimization of drill geometry can reduce the thrust force significantly, and is effective in chip breaking which can improve the chip evacuation during the drilling process.

Finite Element Method Simulation of Drilling Process on Metal-Matrix Composites

2011 ◽  
Vol 188 ◽  
pp. 372-375
Author(s):  
H.L. Zhang ◽  
Jin Chen
Keyword(s):  
Finite Element ◽  
Feed Rate ◽  
Shear Failure ◽  
Thrust Force ◽  
Equivalent Stress ◽  
Damage Model ◽  
Cutting Speed ◽  
Finite Element Method Simulation ◽  
Drilling Process ◽  
Machining Processes

Drilling is one of the complex machining processes, which has been widely applied in the manufacturing area. In this paper, a 3D coupled thermo-mechanical finite element model was used for simulating the thrust force, torque and von Mises equivalent stress at different cutting conditions. The J-C damage model (shear failure) was used in conjunction with the J-C plasticity model, as well as the continuous adaptive remeshing technical. The results show that the thrust force and torque increase with the increasing of the cutting speed and feed rate, and the influence of the feed rate is more obviously.

Research on Drilling Process of Nickel-Based Super-Alloy

2010 ◽  
Vol 33 ◽  
pp. 373-377
Author(s):  
Jian Wu ◽  
Rong Di Han
Keyword(s):  
Feed Rate ◽  
Empirical Formula ◽  
Inconel 718 ◽  
Thrust Force ◽  
Shear Angle ◽  
Drilling Process ◽  
Deformation Characteristics ◽  
Drilling Speed ◽  
Aisi 1045 ◽  
Super Alloy

Nickel-based super-alloy belongs to difficult-to-machine materials, its machinability is low. To find out the difficulties of drilling nickel-based super-alloy, it is necessary to study the drilling process. The study on the drilling process of nickel-based super-alloy Inconel 718 is discussed from two aspects, drilling deformation and drilling forces distribution. For studying the drilling deformation characteristics and influence laws, the drilling chip specimens are obtained by using self-made drilling quick-stop device. Then, the empirical formula of shear angle is also given. Finally, the drilling forces distribution is studied. Results shows that: drilling deformation decreases when the distance to chisel edge, drilling speed and feed rate increases; drilling deformation of Inconel 718 is larger than AISI 1045; the ratio of torque and thrust force on the lead cutting edge is 29%~33%, 74%~77%, respectively; the torque and thrust force of Inconel 718 is about 1.8~2.3 times than that of AISI 1045.

Modeling and Simulation Analysis of the Twist Drill Conical Grinding Method Based on Pro/E Software

2010 ◽  
Vol 160-162 ◽  
pp. 1680-1684
Author(s):  
Xing Jun Gao ◽  
Qing Liu ◽  
Ping Zou ◽  
Jian Song ◽  
Ping Li
Keyword(s):  
Mathematical Model ◽  
Simulation Analysis ◽  
Three Dimensional ◽  
Fundamental Principle ◽  
Drilling Process ◽  
Twist Drill ◽  
Three Dimensional Modeling ◽  
Grinding Method ◽  
Dimensional Modeling ◽  
The Mathematical Model

The fundamental principle of the twist drill conical grinding method was introduced. The mathematical model of the twist drill was established. Mathematical model to establish drill bit is the geometric design, manufacture, cutting analysis and modeling on the basis of the drilling process. According to the twist drill grinding principle, using Pro/E the three-dimensional modeling of the twist drill was completed, and the feature of the conical grinding method was analyzed.

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