Experimental Investigation and Optimization in Rotary Ultrasonic Drilling of C/C Composites

2016 ◽  
Vol 874 ◽  
pp. 313-319
Author(s):  
Song Mei Yuan ◽  
Qi Wu
Keyword(s):  
Feed Rate ◽  
Elevated Temperatures ◽  
Cutting Parameters ◽  
Spindle Speed ◽  
High Fracture Toughness ◽  
Drilling Force ◽  
High Fracture ◽  
Machining Quality ◽  
Ultrasonic Drilling ◽  
Rotary Ultrasonic Drilling

C/C composites are widely used in aviation and aerospace due to their low density, superior specific strength, special elastic modulus at elevated temperatures, small thermal expansion coefficient and high fracture toughness. However, there are numerous problems such as delamination, chipping, poor machining quality and tool wear in drilling of C/C composites due to inhomogeneous, anisotropic, wear resistance and varying thermal properties of the composites. In this paper, related experiments on rotary ultrasonic drilling of C/C composites using diamond core drill were conducted to compare the drilling force and machining quality of ultrasonic drilling with conventional drilling, analyze the rotary ultrasonic drilling mechanism and research the influence of spindle speed, feed rate and ultrasonic amplitude on the drilling force. Experimental results showed that rotary ultrasonic drilling can significantly improve the removal of the chips thus preventing the core drill blockage, effectively reduce the drilling force and improve processing quality. In addition, the drilling force decreased with increasing of spindle speed and ultrasonic amplitude, while it increased with increasing of feed rate. Finally, the cutting parameters were optimized by consideration of the drilling force and efficiency.

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.

Prediction of Surface Roughness and Optimization of Cutting Parameters in CNC Turning of Rotational Features

2020 ◽  
Vol 38 (8A) ◽  
pp. 1143-1153
Author(s):  
Yousif K. Shounia ◽  
Tahseen F. Abbas ◽  
Raed R. Shwaish
Keyword(s):  
Surface Roughness ◽  
Linear Regression ◽  
Regression Model ◽  
Linear Regression Model ◽  
Feed Rate ◽  
Cutting Parameters ◽  
Spindle Speed ◽  
Depth Of Cut ◽  
Non Linear ◽  
Optimization Of Cutting Parameters

This research presents a model for prediction surface roughness in terms of process parameters in turning aluminum alloy 1200. The geometry to be machined has four rotational features: straight, taper, convex and concave, while a design of experiments was created through the Taguchi L25 orthogonal array experiments in minitab17 three factors with five Levels depth of cut (0.04, 0.06, 0.08, 0.10 and 0.12) mm, spindle speed (1200, 1400, 1600, 1800 and 2000) r.p.m and feed rate (60, 70, 80, 90 and 100) mm/min. A multiple non-linear regression model has been used which is a set of statistical extrapolation processes to estimate the relationships input variables and output which the surface roughness which prediction outside the range of the data. According to the non-linear regression model, the optimum surface roughness can be obtained at 1800 rpm of spindle speed, feed-rate of 80 mm/min and depth of cut 0.04 mm then the best surface roughness comes out to be 0.04 μm at tapper feature at depth of cut 0.01 mm and same spindle speed and feed rate pervious which gives the error of 3.23% at evolution equation.

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.

scholarly journals Precise Drilling of Holes in Alumina Ceramic (Al2O3) by Rotary Ultrasonic Drilling and its Parameter Optimization using MOGA-II

Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1059 ◽  
Author(s):  
Hisham Alkhalefah
Keyword(s):  
Feed Rate ◽  
Dimensional Accuracy ◽  
Alumina Ceramic ◽  
Process Variables ◽  
Multi Objective Genetic Algorithm ◽  
Ultrasonic Drilling ◽  
Drilling Quality ◽  
Processing Techniques ◽  
Validation Tests ◽  
Rotary Ultrasonic Drilling

Alumina is an advanced ceramic with applications in dental and medical sciences. Since ceramics are hard and brittle, their conventional machining is expensive, arduous, and time-consuming. As rotary ultrasonic machining is among the most adequate and proficient processing techniques for brittle materials like ceramics. Therefore, in this study, rotary ultrasonic drilling (RUD) has been utilized to drill holes on alumina ceramic (Al2O3). This study investigates the effect of key RUD process variables, namely vibration frequency, vibration amplitude, spindle speed, and feed rate on the dimensional accuracy of the drilled holes. A four-variable three-level central composite design (thirty experiments on three sample plates) is utilized to examine the comparative significance of different RUD process variables. The multi-objective genetic algorithm is employed to determine the optimal parametric conditions. The findings revealed that material removal rates depend on feed rate, while the cylindricity of the holes is mostly controlled by the speed and feed rate of the spindles. The optimal parametric combination attained for drilling quality holes is speed = 4000 rpm, feed rate = 1.5 (mm/min), amplitude = 20 (µm), and frequency = 23 (kHz). The validation tests were also conducted to confirm the quality of drilled holes at the optimized process parameters.

Evaluation of CFRP Hole Quality in Low Frequency Vibration-Assisted Dry Drilling of CFRP/Ti Stacks

2018 ◽  
Author(s):  
Haojun Yang ◽  
Yan Chen ◽  
Jiuhua Xu
Keyword(s):  
Feed Rate ◽  
Kinematic Model ◽  
Mechanical Damage ◽  
Low Frequency ◽  
Spindle Speed ◽  
Hole Quality ◽  
Drilling Force ◽  
Low Frequency Vibration ◽  
The Impact ◽  
Conventional Drilling

Low frequency vibration assisted drilling (LFVAD) is regarded as one of the most promising process in CFRP/Ti stacks drilling. This work carries the investigation of the difference between conventional drilling and LFVAD based on kinematic model. The experiments are conducted under varied vibration amplitude to a specific feed rate, also under varying spindle speeds, feed rates when the ratio of amplitude to feed rate is fixed. Then the hole quality of CFRP is evaluated based on the analysis of drilling force, chip morphology, chip extraction. The results show that there is rarely no difference between conventional drilling and LFVAD in drilling mechanism when the drilling diameter is over 1 mm. Because the impact effect caused by drill vibration is already weak. It is found that the severe mechanical damage of the CFRP holes surface could be significantly reduced due to the fragmented chips obtained in vibration drilling. The maximum instantaneous feed rate combined with feed rate and amplitude plays a significant role in CFRP hole quality. Lower maximum instantaneous feed rate results in better hole wall quality and less entry delamination. Spindle speed has no visible influence on entry delamination, while higher spindle speed improves the hole surface quality due to the resin coating phenomenon.

Estimation of fractal dimension and surface roughness based on material characteristics and cutting conditions in the end milling of carbon steels

2015 ◽  
Vol 231 (8) ◽  
pp. 1423-1437 ◽  
Author(s):  
Xue Zuo ◽  
Hua Zhu ◽  
Yuankai Zhou ◽  
Jianhua Yang
Keyword(s):  
Surface Roughness ◽  
Fractal Dimension ◽  
Feed Rate ◽  
End Milling ◽  
Cutting Parameters ◽  
Carbon Steels ◽  
Spindle Speed ◽  
Numerical Control ◽  
Material Hardness ◽  
Milled Surface

Cutting parameters and material properties have important effects on the quality of milled surface, which can be characterized by fractal dimension and surface roughness. The relationships between two surface parameters (surface roughness and fractal dimension) and material hardness, elongation, spindle speed and feed rate were investigated, respectively, in this study. Four carbon steels, that is, AISI 1020, Gr 50, 1045 and 1566, were milled with five spindle speeds and four feed rates on a computer numerical control machine. The surface topographies were measured with a three-dimensional profiler. The surface profiles were obtained by re-sampling the data points on the surface topography in the measurement direction. The surface roughness and fractal dimension were calculated from the two-dimensional profiles, where the fractal dimension was obtained by the root-mean-square method. The results showed that for specific spindle speed and feed rate, the roughness of the milled surface decreased with the workpiece hardness, whereas the elongation and fractal dimension increased with the hardness. Based on the material hardness and elongation, spindle speed and feed rate, empirical formulae were established to quantitatively estimate the surface roughness and fractal dimension. Moreover, the spindle speed and feed rate can be easily calculated from the empirical formulae to achieve a surface with the desired surface roughness and fractal dimension. The empirical formulae have been demonstrated with the experiments and were shown to be applicable in estimating the surface roughness and fractal dimension for all carbon steels in end milling. The results are instructive for the fractal dimension estimation of the machined surfaces of carbon steel, which has not been previously studied.

Effects of Additives on the Interfacial Microstructure of SiC Fiber/Li2O-Al2O3-6SiO2 Glass-Ceramic Composites

1991 ◽  
Vol 49 ◽  
pp. 924-925
Author(s):  
J.Y. Hsu ◽  
Y. Berta ◽  
R.F. Speyer
Keyword(s):  
Flexural Strength ◽  
Glass Ceramic ◽  
Elevated Temperatures ◽  
Ceramic Composites ◽  
Interfacial Microstructure ◽  
High Fracture Toughness ◽  
Matrix Composition ◽  
High Fracture ◽  
Sic Fiber ◽  
The Matrix

SiC fiber reinforced lithia-alumina-silica glass-ceramic composites have exhibited superior mechanical properties at room and elevated temperatures. The flexural strength of these composites is 3 to 4 times larger than that of monolithic glass-ceramics. The high flexural strength of these composites is due to the transfer of the applied load from the matrix to the stronger and stiffer SiC fiber reinforcement. These composites also have demonstrated very high fracture toughness, KIC (critical stress intersity factor) values of ∼ 17 MPa m1/2, which is attributed to an amorphous carbon-rich interfacial layer between the fiber and matrix. Nb2O2 has been added to the matrix composition in order to develop a NbC layer outside the amorphous C-rich layer after thermal processing, thereby buffering the fiber/matrix reactivity (avoid carbon forming CO gas which would deteriorate the matrix).

Investigation into rotary mode ultrasonic drilling of bioceramic: an experimental study with PSO-TLBO based evolutionary optimization

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Ravi Pratap Singh ◽  
Narendra Kumar ◽  
Ashutosh Kumar Gupta ◽  
Madhusudan Painuly
Keyword(s):  
Mathematical Model ◽  
Feed Rate ◽  
Fitness Function ◽  
Real Life ◽  
Spindle Speed ◽  
Ultrasonic Power ◽  
Material Loss ◽  
Additional Advantage ◽  
Content Type ◽  
Ultrasonic Drilling

Purpose The purpose of this paper is to investigate experimentally the effect of several input process factors, namely, feed rate, spindle speed, ultrasonic power and coolant pressure, on hole quality measures (penetration rate [PR] and chipping diameter [CD]) in rotary mode ultrasonic drilling of macor bioceramic material. Design/methodology/approach The main experiments were planned using the response surface methodology (RSM). Scanning electron microscopy was also used to examine and study the microstructure of machined samples. This study revealed the existence of dominant brittle fracture and little plastic flow that resulted in a material loss from the base work surface. Experiment findings have shown the dependability and adequacy of the proposed mathematical model. Findings The percentage of brittle mode deformation rises as the penetration depth of abrasives increases (at increasing levels of feed rate). This was due to the fact that at greater depths of indentation, material loss begins in the form of bigger chunks and develops inter-granular fractures. These stated causes have provided an additional advantage to increasing the CD over the machined rod of bioceramic. The desirability method was also used to optimize multi-response measured responses (PR and CD). The mathematical model created using the RSM method will be very useful in industrial revelation. Furthermore, the investigated answers’ particle swarm optimization (PSO) and teacher-learner-based optimization (TLBO) make the parametric analysis more relevant and productive for real-life industrial practices. Originality/value Macor bioceramic has been widely recognized as one of the most highly demanded innovative dental ceramics, receiving expanded industry approval because of its outstanding and superior characteristics. However, effective and efficient processing remains a problem. Among the available contemporary machining methods introduced for processing typical and advanced materials, rotary mode ultrasonic machining has been identified as one of the best suitable candidates for precise processing of macor bioceramics, as this process produces thermal damage-free profiles, as well as high accuracy and an increased material removal rate. The optimized combined setting obtained using PSO is feed rate = 0.16 mm/s, spindle speed = 4,500 rpm, ultrasonic power = 60% and coolant pressure = 280 kPa with the value of fitness function is 0.0508. The optimized combined setting obtained using TLBO is feed rate = 0.06 mm/s, spindle speed = 2,500 rpm, ultrasonic power = 60% and coolant pressure = 280 kPa with the value of fitness function is 0.1703.

Effects of Cutting Parameters on Hole Integrity when Drilling GFRP and HFRP Composites

2013 ◽  
Vol 845 ◽  
pp. 960-965
Author(s):  
Mohd Azuwan Maoinser ◽  
Faiz Ahmad ◽  
Safian Sharif
Keyword(s):  
Composite Materials ◽  
Feed Rate ◽  
Cutting Parameters ◽  
Spindle Speed ◽  
Matrix Cracking ◽  
Fiber Reinforced ◽  
Damage Factor ◽  
Electron Microscopic ◽  
Pull Out

The demand for mechanical fastening in composite materials is increasing due to their potential in large assemblies, aerospace and automotive industries. In practice, small components are integrated into large assemblies drilling holes in composite materials. Drilling defect free holes in composite presents many challenges during part assembly and services. This study presents the effects of cutting parameters used for drilling holes in glass fiber reinforced polymeric (GFRP) composites and hybrid fiber reinforced polymeric (HFRP) composites. Both the composites plates of 3 mm thickness were fabricated using a hand lay-up technique for the purpose of evaluating the effects of parameters on the quality of drilled holes. The holes were drilled using a 5 mm solid carbide twist drill at different spindle speed and feed rate. The quality of holes was assessed with respect to damage factor (Fd) and surface roughness (Ra) of the drilled holes. Results showed that the HFRP composite experienced lower damage factor (Fd) as compared to GFRP composite at lower feed rate or spindle speed. Scanning electron microscopic (SEM) examination revealed that the occurrence of delamination, fiber pull-out and matrix cracking was accelerated in the drilled holes at high spindle speed and feed rate.

The influence of cutting parameters on micro-topography of frequency features extracted from the machined KH2PO4 surfaces

2020 ◽  
Vol 234 (14) ◽  
pp. 1762-1770
Author(s):  
Qilong Pang ◽  
Liangjie Kuang ◽  
Youlin Xu
Keyword(s):  
Wavelet Transform ◽  
Feed Rate ◽  
Cutting Parameters ◽  
Spindle Speed ◽  
Depth Of Cut ◽  
Continuous Wavelet ◽  
Power Spectral ◽  
Frequency Features ◽  
Micro Topography ◽  
Frequency Feature

Using reasonable cutting parameters of machining process is an effective and convenient means of improving the topography of the machined surfaces. In this study, the methods to find optimised cutting parameters can be obtained by studying the relationship between the cutting parameters and the micro-topography of frequency features in the machined KH2PO4 surfaces. Using the power spectral density and continuous wavelet transform methods, the 2D micro-topographies of frequencies corresponding to different cutting parameters are extracted from the machined KH2PO4 surfaces. The results for the extracted micro-topography are used to analyse the influence of cutting parameters on the spatial frequency feature which consists of the wavelength and amplitude. The middle-frequency feature reflects the variations of depth of cut and spindle speed, and the amplitude of it is directly proportional to depth of cut and spindle speed. The low-frequency feature reflects the variations of the feed rate and decreases to a smaller value when the feed rate increases. The high-frequency feature is mainly affected by the material properties and the vibrations that occur during processing. Comparing the micro-topography of frequencies under different cutting parameters, the depth of cut (3 μm), the spindle speed (400 r/min) and the feed rate (8 μm/r) are the optimised cutting parameters for the machine tools used in this article. In the process of reconstructing the arbitrary frequency topography, the continuous wavelet transform method can compensate for the deficiencies of the power spectral density method for extracting frequencies.

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