Hole quality assessment in drilling process of basalt/epoxy composite laminate subjected to the magnetic field

2019 ◽  
Vol 20 (6) ◽  
pp. 620 ◽  
Author(s):  
Farhad Najarian ◽  
Roozbeh Alipour ◽  
Abbas Razavykia ◽  
Ali Farokhi Nejad
Keyword(s):  
Magnetic Field ◽  
Composite Laminate ◽  
Epoxy Composite ◽  
Quality Parameters ◽  
Drilling Process ◽  
Reinforced Composites ◽  
Hole Quality ◽  
Machining Processes ◽  
Drilling Parameters ◽  
The Magnetic Field

Drilling is one of the most important machining processes which are currently carried out on fiber-reinforced composites. These composites possess a layered structure and different properties through their thickness. When drilling such structures, internal defects like delamination occur, caused by the drilling forces and their uneven distribution among the plies. The current study investigates the effect of magnetic field on drilling process of basalt/epoxy composite laminate in order to reduce delamination and the thrust force and improve some hole quality parameters i.e. roughness and cylindricity. A comparison is made between the responses for both normal drilling and drilling with applying a magnetic field. For this purpose, after finding the best combinations of normal drilling parameters, magnetic field is applied to the different configurations of solenoids on the setup of the drilling process. The results highlighted that using different magnet solenoids on the top and the bottom of drilling zone reduces the delamination and can obtain better roughness and cylindricity with lower damage.

A Novel Active Online Electromagnetic Balancing Method—Principle and Structure Analysis

2012 ◽  
Vol 134 (3) ◽  
Author(s):  
Shilei Ma ◽  
Shiyuan Pei ◽  
Lin Wang ◽  
Hua Xu
Keyword(s):  
Magnetic Field ◽  
Electromagnetic Force ◽  
Magnetic Force ◽  
Cutting Tools ◽  
Field Analysis ◽  
Iron Core ◽  
Machining Processes ◽  
Magnetic Field Analysis ◽  
Precision Finishing ◽  
The Magnetic Field

Vibrations caused by the imbalance of a rotor are a frequently encountered problem in machining processes. Especially in high-precision finishing, the workpiece quality is strongly related to the vibration of the machine-tool spindle, which is mainly caused by mass imbalance and cannot be completely eliminated in cutting tools with nonaxisymmetrical structures. An imbalance in centrifugal force is generated by rotor rotation and increases rapidly with rotational speed. A novel active online electromagnetic balancing method based on static magnetic-field analysis is proposed, and an active online electromagnetic balancing device (AOEBD) based on this method was developed under these conditions. The magnetic-field distribution and electromagnetic force generated by the device were analyzed by finite-element modeling. The influence on the electromagnetic force of the misalignment between the rotor and the iron core was investigated. Factors influencing the magnetic force of the device were determined, and reasonable reference values were suggested. The critical eccentricity was also provided. Experiments had been done at last, and the experimental results presented a good performance of this kind of balancing device.

Improving machining stability of AISI-4140 with magnetic field

2022 ◽  
pp. 095440622110649
Author(s):  
Mehmet Alper Sofuoglu ◽  
Fatih Hayati Çakir
Keyword(s):  
Magnetic Field ◽  
Surface Roughness ◽  
Cutting Temperature ◽  
Cutting Parameters ◽  
Magnetic Flux Density ◽  
Machining Processes ◽  
Aisi 4140 ◽  
Neodymium Magnets ◽  
Stiffness And Damping ◽  
The Magnetic Field

Several methods have been developed in order to improve the traditional machining processes and machining outputs. In this study, the effect of the magnetic field on the turning process was investigated. AISI-4140 was machined with different cutting speeds and magnetic flux density magnitudes. The magnetic field was generated with neodymium magnets. Machining stability, surface roughness, and maximum cutting temperature were measured. Additionally, chip shapes were examined. The machining stability was determined by measuring the vibration amplitude and other vibrational parameters (natural frequency, stiffness, and damping coefficients). Conventional turning and magnetic assisted turning were performed under the same cutting parameters consecutively, and the results were compared. According to the results, it was observed that neodymium magnets attached to the cutting tool improve machining stability and damping properties. Surface roughness was decreased between 6%–10% in magnetic assisted turning. Furthermore, it has been observed that the maximum cutting temperatures have been increased between 10%–45% in the magnetic assisted machining. Besides, it can be said that magnets contribute to improving chip control by collecting the chips on them while machining AISI-4140 steel.

scholarly journals Analysis of Hole Quality and Chips Formation in the Dry Drilling Process of Al7075-T6

Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 891
Author(s):  
Numan Habib ◽  
Aamer Sharif ◽  
Aqib Hussain ◽  
Muhammad Aamir ◽  
Khaled Giasin ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Feed Rate ◽  
High Speed Steel ◽  
Spindle Speed ◽  
Drilling Process ◽  
Hole Size ◽  
Hole Quality ◽  
Dry Drilling ◽  
Drilling Parameters ◽  
The Impact

Millions of holes are produced in many industries where efficient drilling is considered the key factor in their success. High-quality holes are possible with the proper selection of drilling process parameters, appropriate tools, and machine setup. This paper deals with the effects of drilling parameters such as spindle speed and feed rate on the chips analysis and the hole quality like surface roughness, hole size, circularity, and burr formation. Al7075-T6 alloy, commonly used in the aerospace industry, was used for the drilling process, and the dry drilling experiments were performed using high-speed steel drill bits. Results have shown that surface roughness decreased with the increase in spindle speed and increased with the increase in the feed rate. The hole size increased with the high spindle speed, whereas the impact of spindle speed on circularity error was found insignificant. Furthermore, short and segmented chips were achieved at a high feed rate and low spindle speed. The percentage contribution of each input parameter on the output drilling parameters was evaluated using analysis of variance (ANOVA).

Magnetic Field Effects on Laser Drilling

2013 ◽  
Vol 135 (6) ◽  
Author(s):  
Chang Ye ◽  
Gary J. Cheng ◽  
Sha Tao ◽  
Benxin Wu
Keyword(s):  
Magnetic Field ◽  
Laser Ablation ◽  
Laser Drilling ◽  
Nanosecond Laser ◽  
Drilling Process ◽  
Magnetic Field Effects ◽  
Drilling Depth ◽  
Field Effects ◽  
Nanosecond Laser Ablation ◽  
The Magnetic Field

A magnetic field-assisted laser drilling process has been studied, where nanosecond laser ablation is performed under an external magnetic field. The study shows that the magnetic field-assisted laser drilling process produces deeper drilling depth and generates more confined plasma plume and relative less residual, as compared with laser drilling without magnetic field. This phenomenon has been rarely reported in the literature. The magnetic field effects on laser ablation have been analyzed analytically and a hypothesized explanation has been proposed based on the effect of the magnetic field on the plasma produced during laser ablation.

scholarly journals Performance Analysis of Multi-Spindle Drilling of Al2024 with TiN and TiCN Coated Drills Using Experimental and Artificial Neural Networks Technique

2020 ◽  
Vol 10 (23) ◽  
pp. 8633
Author(s):  
Muhammad Aamir ◽  
Majid Tolouei-Rad ◽  
Ana Vafadar ◽  
Muhammad Nouman Amjad Raja ◽  
Khaled Giasin
Keyword(s):  
Surface Roughness ◽  
Thrust Force ◽  
Drilling Process ◽  
Hole Quality ◽  
Drilling Performance ◽  
Coated Tools ◽  
Drilling Parameters ◽  
Increase Productivity ◽  
Coated Carbide ◽  
Multiple Holes

Multi-spindle drilling simultaneously produces multiple holes to save time and increase productivity. The assessment of hole quality is important in any drilling process and is influenced by characteristics of the cutting tool, drilling parameters and machine capacity. This study investigates the drilling performance of uncoated carbide, and coated carbide (TiN and TiCN) drills when machining Al2024 aluminium alloy. Thrust force and characteristics of hole quality, such as the presence of burrs and surface roughness, were evaluated. The results show that the uncoated carbide drills performed better than the TiN and TiCN coated tools at low spindle speeds, while TiCN coated drills produced better hole quality at higher spindle speeds. The TiN coated drills gave the highest thrust force and poorest hole quality when compared with the uncoated carbide and TiCN coated carbide drills. Additionally, a multi-layer perceptron neural network model was developed, which could be useful for industries and manufacturing engineers for predicting the surface roughness in multi-hole simultaneous drilling processes.

Observing the galactic magnetic field

1967 ◽  
Vol 31 ◽  
pp. 375-380
Author(s):  
H. C. van de Hulst
Keyword(s):  
Magnetic Field ◽  
Fair Agreement ◽  
Solar Neighbourhood ◽  
Galactic Magnetic Field ◽  
The Magnetic Field

Various methods of observing the galactic magnetic field are reviewed, and their results summarized. There is fair agreement about the direction of the magnetic field in the solar neighbourhood:l= 50° to 80°; the strength of the field in the disk is of the order of 10-5gauss.

Evolution of Large-Scale Coronal Structures

1994 ◽  
Vol 144 ◽  
pp. 29-33
Author(s):  
P. Ambrož
Keyword(s):  
Magnetic Field ◽  
Field Line ◽  
Large Scale ◽  
Coronal Magnetic Field ◽  
Source Surface ◽  
Solar Cycles ◽  
Characteristic Relationship ◽  
The Magnetic Field ◽  
Coronal Structures

AbstractThe large-scale coronal structures observed during the sporadically visible solar eclipses were compared with the numerically extrapolated field-line structures of coronal magnetic field. A characteristic relationship between the observed structures of coronal plasma and the magnetic field line configurations was determined. The long-term evolution of large scale coronal structures inferred from photospheric magnetic observations in the course of 11- and 22-year solar cycles is described.Some known parameters, such as the source surface radius, or coronal rotation rate are discussed and actually interpreted. A relation between the large-scale photospheric magnetic field evolution and the coronal structure rearrangement is demonstrated.

Emergence of Twisted Magnetic Flux Related Sigmoidal Brightening

2000 ◽  
Vol 179 ◽  
pp. 263-264
Author(s):  
K. Sundara Raman ◽  
K. B. Ramesh ◽  
R. Selvendran ◽  
P. S. M. Aleem ◽  
K. M. Hiremath
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Magnetic Flux ◽  
Ultra Violet ◽  
Active Regions ◽  
Morphological Properties ◽  
Energy Storage And Conversion ◽  
The Sun ◽  
X Rays ◽  
The Magnetic Field

Extended AbstractWe have examined the morphological properties of a sigmoid associated with an SXR (soft X-ray) flare. The sigmoid is cospatial with the EUV (extreme ultra violet) images and in the optical part lies along an S-shaped Hαfilament. The photoheliogram shows flux emergence within an existingδtype sunspot which has caused the rotation of the umbrae giving rise to the sigmoidal brightening.It is now widely accepted that flares derive their energy from the magnetic fields of the active regions and coronal levels are considered to be the flare sites. But still a satisfactory understanding of the flare processes has not been achieved because of the difficulties encountered to predict and estimate the probability of flare eruptions. The convection flows and vortices below the photosphere transport and concentrate magnetic field, which subsequently appear as active regions in the photosphere (Rust & Kumar 1994 and the references therein). Successive emergence of magnetic flux, twist the field, creating flare productive magnetic shear and has been studied by many authors (Sundara Ramanet al.1998 and the references therein). Hence, it is considered that the flare is powered by the energy stored in the twisted magnetic flux tubes (Kurokawa 1996 and the references therein). Rust & Kumar (1996) named the S-shaped bright coronal loops that appear in soft X-rays as ‘Sigmoids’ and concluded that this S-shaped distortion is due to the twist developed in the magnetic field lines. These transient sigmoidal features tell a great deal about unstable coronal magnetic fields, as these regions are more likely to be eruptive (Canfieldet al.1999). As the magnetic fields of the active regions are deep rooted in the Sun, the twist developed in the subphotospheric flux tube penetrates the photosphere and extends in to the corona. Thus, it is essentially favourable for the subphotospheric twist to unwind the twist and transmit it through the photosphere to the corona. Therefore, it becomes essential to make complete observational descriptions of a flare from the magnetic field changes that are taking place in different atmospheric levels of the Sun, to pin down the energy storage and conversion process that trigger the flare phenomena.

On the Configuration of the Magnetic Field of β CrB

1976 ◽  
Vol 32 ◽  
pp. 613-622
Author(s):  
I.A. Aslanov ◽  
Yu.S. Rustamov
Keyword(s):  
Magnetic Field ◽  
Field Strength ◽  
Radial Velocity ◽  
Magnetic Field Strength ◽  
Complex Shape ◽  
Rotation Period ◽  
Field Variation ◽  
Magnetic Field Variation ◽  
Secular Variations ◽  
The Magnetic Field

SummaryMeasurements of the radial velocities and magnetic field strength of β CrB were carried out. It is shown that there is a variability with the rotation period different for various elements. The curve of the magnetic field variation measured from lines of 5 different elements: FeI, CrI, CrII, TiII, ScII and CaI has a complex shape specific for each element. This may be due to the presence of magnetic spots on the stellar surface. A comparison with the radial velocity curves suggests the presence of a least 4 spots of Ti and Cr coinciding with magnetic spots. A change of the magnetic field with optical depth is shown. The curve of the Heffvariation with the rotation period is given. A possibility of secular variations of the magnetic field is shown.

Sign in / Sign up

Export Citation Format

Share Document