scholarly journals Investigations on the Wear Rate of Sintering Diamond Core Bit during the Hole Drilling Process of Al2O3 Bulletproof Ceramics

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Lei Zheng ◽  
Chen Zhang ◽  
Xianglong Dong ◽  
Shitian Zhao ◽  
Weidong Wu ◽  
...  
Keyword(s):  
Wear Rate ◽  
Spindle Speed ◽  
Machining Process ◽  
Hole Drilling ◽  
Drilling Process ◽  
Thin Wall ◽  
Diamond Grit ◽  
Machining Quality ◽  
Test Conditions ◽  
Finer Diamond

Bulletproof ceramics are usually hard and brittle with high elastic modulus, high compressive strength, and low tensile strength. While machining bulletproof ceramics, severe tool wear makes it difficult to obtain desired machining quality and efficiency, especially in hole drilling. In this work, an intensive experimental study on the overall wear rate of the sintering diamond thin-wall core bit during the hole drilling of Al2O3 bulletproof ceramics (99 wt.%) has been carried out. The quality loss of the bit after each hole drilled was selected for representing the overall wear rate of the bit. Based on experimental data, the influences of the main bit performance and machining process parameters on the overall wear rate of the bit have been analyzed. According to the results discussed, under the test conditions, finer diamond grit, higher diamond concentration, lower number of water gaps, thinner wall thickness, or lower bit load all can decrease the wear rate of the bit. However, within a certain range, the spindle speed has little influence on the overall wear resistance of the bit, but when the spindle speed increases, the machining efficiency can be significantly improved. The results obtained in this work can offer a valuable reference for the use of sintering diamond thin-wall core bits in the hole drilling of bulletproof ceramics.

scholarly journals Temperature monitoring in the subsurface during single lip deep hole drilling

2020 ◽  
Vol 87 (12) ◽  
pp. 757-767
Author(s):  
Robert Wegert ◽  
Vinzenz Guski ◽  
Hans-Christian Möhring ◽  
Siegfried Schmauder
Keyword(s):  
Cutting Parameters ◽  
Drill Hole ◽  
Machining Process ◽  
Hole Drilling ◽  
Drilling Process ◽  
Deep Hole ◽  
Machining Processes ◽  
Deep Hole Drilling ◽  
Feed Force ◽  
Cutting Zone

AbstractThe surface quality and the subsurface properties such as hardness, residual stresses and grain size of a drill hole are dependent on the cutting parameters of the single lip deep hole drilling process and therefore on the thermomechanical as-is state in the cutting zone and in the contact zone between the guide pads and the drill hole surface. In this contribution, the main objectives are the in-process measurement of the thermal as-is state in the subsurface of a drilling hole by means of thermocouples as well as the feed force and drilling torque evaluation. FE simulation results to verify the investigations and to predict the thermomechanical conditions in the cutting zone are presented as well. The work is part of an interdisciplinary research project in the framework of the priority program “Surface Conditioning in Machining Processes” (SPP 2086) of the German Research Foundation (DFG).This contribution provides an overview of the effects of cutting parameters, cooling lubrication and including wear on the thermal conditions in the subsurface and mechanical loads during this machining process. At first, a test set up for the in-process temperature measurement will be presented with the execution as well as the analysis of the resulting temperature, feed force and drilling torque during drilling a 42CrMo4 steel. Furthermore, the results of process simulations and the validation of this applied FE approach with measured quantities are presented.

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.

Research of Machining Process on 17-4PH Stainless Steel Superfine Deep-Hole Drilling

2014 ◽  
Vol 633-634 ◽  
pp. 688-692 ◽  
Author(s):  
Zhan Feng Liu ◽  
Han Chen Wang
Keyword(s):  
Stainless Steel ◽  
Wall Thickness ◽  
Machining Process ◽  
New Method ◽  
Hole Drilling ◽  
Drilling Process ◽  
Deep Hole ◽  
Deep Hole Drilling ◽  
Gun Drill

Through the analysis of superfine deep-hole drilling process, we used the combination of gun drill and BTA deep-hole drilling process for 17-4PH (0Cr17Ni4Cu4Nb) stainless steel deep-hole drilling test. We measured wall thickness point by point, and calculated the conversion of the eccentricity in a deviation axis line. Which fully embodies the advantage of this process for stainless steel 17-4PH, and provides a new method in super hardness material deep-hole drilling field.

The Effect of Spindle Speed and Feed Rate on Hole Diameter of High-Speed Micro-Drilling for Micro-Screen Manufacture

2020 ◽  
Vol 402 ◽  
pp. 125-130
Author(s):  
Muhammad Tadjuddin ◽  
Suhaeri ◽  
Muhammad Dirhamsyah ◽  
Aulia Udink ◽  
Fatur Rahmatsyah
Keyword(s):  
Feed Rate ◽  
High Speed ◽  
Tool Material ◽  
Spindle Speed ◽  
Machining Process ◽  
Drilling Process ◽  
Machining Parameters ◽  
A Value ◽  
Micro Drilling ◽  
Hole Dimensions

The micro-drill is one of the manufacturing processes that is developing, especially in the electronics, aerospace, pharmaceutical, and automotive industries. This paper describes the results of the high-speed microdrill process in stainless steel. The drilling process is used to make the micro screen. The cutting tool material is tungsten carbide with a diameter of 0.2 mm. Drilling holes arranged in a honeycomb configuration. The machining parameters used are spindle speed of 20,000 rpm, 22,000 rpm, 24,000 rpm, and feed rate of 1 mm/min, 1.5 mm/min, 2 mm/min. Micro-drilling holes are visually analyzed using a Scanning Electron Microscope (SEM) to measure the accuracy of the hole dimensions. The results of the machining process found that the most significant deviation of the hole dimension size with a value of 0.276 mm occurred at a spindle speed of 20,000 rpm with a feed of 1 mm/min. While the deviation of the smallest hole size with a value of 0.2019 mm occurred at a spindle speed of 24,000 rpm with a feed of 2 mm/min, these results conclude that the accuracy of the hole dimensions will increase in proportion to the increase in spindle speed and feeding.

Experimental Investigation of Drilling Incorporated Electrochemical Discharge Machining

2014 ◽  
Author(s):  
Baoyang Jiang ◽  
Shuhuai Lan ◽  
Jun Ni
Keyword(s):  
Material Removal Rate ◽  
Material Removal ◽  
Removal Rate ◽  
Machining Process ◽  
Hole Drilling ◽  
Tool Electrode ◽  
Drilling Process ◽  
Electrochemical Discharge Machining ◽  
Electrochemical Discharge ◽  
Micro Drilling

Electrochemical discharge machining (ECDM) is a non-conventional micromachining technology, and is highlighted for non-conductive brittle materials. However, the outcomes of ECDM have many restrictions in application due to limitations on efficiency, accuracy, and machining quality. In this paper, a drilling incorporated ECDM process is presented and analyzed to enhance material removal rate in ECDM drilling process. Incorporating micro-drilling into ECDM significantly increases the rate of material removal, especially in deep hole drilling. As fundamentals of the machining process, material removal mechanisms have been investigated to account for the increment in material removal rate by incorporating micro-drilling. Vibration of tool electrode, induced by a piezo-actuator, was introduced to further enhance material removal rate. Quantitative studies were conducted to determine the appropriate process parameters of drilling incorporated ECDM with tool vibration.

Analysis of Deep Hole Drilling in Presence of Electromagnetic Field Using Taguchi Technique

2014 ◽  
Author(s):  
F. Najarian ◽  
M. Y. Noordin ◽  
F. M. Nor ◽  
D. Kurniawan
Keyword(s):  
Electromagnetic Field ◽  
Spindle Speed ◽  
Hole Drilling ◽  
Deep Hole ◽  
Taguchi Technique ◽  
Deep Hole Drilling ◽  
Machining Quality ◽  
Control Factors ◽  
Cylindricity Error

Electromagnetic field assisted machining is potential and is of particular interest to be explored to improve machining quality with minimum environmental effect. In this study, the effect of electromagnetic field on tool and workpiece is analyzed along with the effects of presence of drilling bush, feedrate, and spindle speed to the quality of hole for deep hole drilling. The effect of these control factors to the drilled hole’s cylindricity error and roundness error was determined using Taguchi technique. L16 orthogonal array design of experiments was used, with regression model was calculated and tested using analysis of variance. Spindle speed was found to be the only significant factor, with other factors did not give significant effect to roundness or cylindricity, except for tool magnetization which affected cylindricity. Issues with magnetization system are likely hinder the magnetic field to exhibit potential to improve machining quality, and should be addressed for future study.

scholarly journals Effect of Drilling Process Parameters on Surface Roughness of LM6/B4C Composites

2019 ◽  
Vol 9 (2) ◽  
pp. 3835-3838 ◽  
Keyword(s):  
Surface Roughness ◽  
Process Parameters ◽  
Signal To Noise Ratio ◽  
Matrix Material ◽  
Stir Casting ◽  
Spindle Speed ◽  
Machining Process ◽  
Ratio Method ◽  
Drilling Process ◽  
Casting Technique

Metal matrix composites are a new course of materials with superior properties to those of the components. Such materials ' machining is distinct from that of traditional materials. So the optimization of machining process parameters becomes inevitable. By applying Taguchi's Signal-to-Noise ratio method, this paper examines the effects of drilling process parameter such as feed, spindle speed, drill material and percentage reinforcement on the drilled hole’s surface roughness. Variance analysis was used to evaluate each system parameter's contribution to surface roughness. The composites were manufactured by stir casting technique using aluminium alloy (LM6) as matrix material and boron carbide particulates at 3%, 6% and 9% by weight as material for the reinforcement. There are four factors investigated each at three levels, so 34 which implies 81 experiments has to be conducted, but by using Design of Experiments approach 27 experiments were conducted using L27 orthogonal array The minimum surface roughness measured for the hole was 1.08 µm at combination of 3000 rpm spindle speed, 50 mm/min feed rate, 3% reinforcement and Carbide drill.

scholarly journals Optimization of CFRP Micro Drilling Parameter using 2-Level Factorial Method Towards Thrust Force

2019 ◽  
Vol 9 (2) ◽  
pp. 4487-4491
Keyword(s):  
Material Properties ◽  
Feed Rate ◽  
Optimum Parameter ◽  
Thrust Force ◽  
Weight Ratio ◽  
Spindle Speed ◽  
Material Behavior ◽  
Machining Process ◽  
Drilling Process ◽  
Micro Drilling

Carbon Fiber Reinforced Polymer (CFRP) is extensively used in aircraft and automotive industries due to it exceptional material properties such as high strength to weight ratio and corrosion resistance. Nevertheless, micro drilling process of CFRP material poses various challenge as it has irregular material properties along the structure. High cutting force which lead to poor hole quality is one of the issues that always occur when drilling this material. Hence, the understanding on the relationship between process parameter and material behavior is vital to achieve optimum performance of machining process. The experiment was carried out using 2-level factorial design with variable spindle speed range of 8,000 – 12,000 rpm and feed rate range of 0.01-0.015 mm/rev. Micro drill bit with diameter of 0.9 mm was used and new fresh drill were used for every run to avoid tool wear effect. As a result, lower thrust force of 6.3742 N is obtained from the combination of spindle speed 10k rpm and feed rate 0.0125 N. Therefore, it can be concluded that, optimum parameter falls between the range of 8,000 – 12,000 rpm of spindle speed and 0.01-0.015 mm/rev of feed rate. Validation of the optimum parameter suggested from 2-level factorial which are 8,000 rpm and 0.01 mm/rev is executed. The final result obtained shows 4.5% of error from targeted value and this result is absolutely acceptable and portray the reliability of the experiment.

Einfluss des Tiefbohrens auf die Schwingfestigkeit*/Influence of deep hole drilling on the fatigue resistance of components made of quenched and tempered steel 42CrMo4+QT (AISI 4140)

2018 ◽  
Vol 108 (11-12) ◽  
pp. 767-772
Author(s):  
J. Nickel ◽  
N. Baak ◽  
D. Biermann ◽  
F. Walther
Keyword(s):  
Residual Stresses ◽  
Dynamic Load ◽  
Machining Process ◽  
Hole Drilling ◽  
Drilling Process ◽  
Deep Hole ◽  
Deep Hole Drilling ◽  
Aisi 4140 ◽  
Key Factor ◽  
Quenched And Tempered Steel

Die Oberflächen- und Randzoneneigenschaften von mechanisch bearbeiteten Bauteilen sind ein Schlüsselfaktor für deren Schwingfestigkeit und werden stark durch den Bearbeitungsprozess beeinflusst. In dieser Studie wird der Ansatz untersucht, während des Einlippentiefbohrens gezielt Eigenspannungen in die Bohrungswand einzubringen und die Mikrostruktur der Bohrungswand so zu beeinflussen, dass die Bauteile einer höheren zyklischen Belastung standhalten.   The surface and subsurface properties of mechanically machined components are a key factor for their fatigue performance and are strongly influenced by the parameters of the machining process. This study investigates the approach of inducing residual stresses into the bore wall during single-lip deep hole drilling process and influencing the microstructure of the bore wall so that the components can withstand a higher dynamic load.

Modeling of Surface Roughness in Drilling of MDF Panels

2015 ◽  
Vol 766-767 ◽  
pp. 831-836 ◽  
Author(s):  
T.N. Valarmathi ◽  
K. Palanikumar ◽  
S. Sekar
Keyword(s):  
Surface Roughness ◽  
Feed Rate ◽  
Cutting Forces ◽  
Spindle Speed ◽  
Machining Process ◽  
Drilling Process ◽  
Composite Panels ◽  
Wood Composite ◽  
Control Parameters ◽  
Input Control

Medium density fiberboard wood composite panels are preferred for many domestic and industrial applications over the natural wood because of their high-quality properties. The aesthetic appearance of wood composites makes them suitable for interior and exterior construction works. Among various machining process, drilling is the most frequently used machining operation in the furniture industry in assembly of panel products. During drilling process the drill exhibits cutting forces such as thrust force and torque. The surface quality of the drilled holes are mainly affected by the cutting forces developed during drilling process which causes surface roughness, delamination like damages which leads to the rejection of the final product. Hence the reduction of the drilling defects, the control of the cutting forces is very much essential. The drilling parameters play an important role in controlling the cutting forces. The objective of this work is to study the influence of input control parameters such as spindle speed, feed rate and point angle on surface roughness in drilling of MDF panels to obtain the optimal cutting conditions. In the present study the drilling experiments are conducted using Taguchi design of experiments on wood composite panels with high speed steel (HSS) twist drills with different point angles on vertical machining center using at dry condition. Three levels and three factors are considered. Taguchi L27 orthogonal array is used. Response surface methodology is used to develop a mathematical model to predict the influence of input control parameters on cutting forces. Analysis of variance is used to check the adequacy of the model. Surface roughness is increased with an increase of feed rate and drill point angle and decreased with an increase in the spindle speed. It is revealed that high spindle speed with low feed rate and smaller point angle combination gives better results in drilling of wood composite panels.

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