Investigations on Laser Dressing of Grinding Wheels—Part II: Grinding Performance of a Laser Dressed Aluminum Oxide Wheel

1989 ◽  
Vol 111 (3) ◽  
pp. 253-261 ◽  
Author(s):  
N. Ramesh Babu ◽  
V. Radhakrishnan
Keyword(s):  
Laser Radiation ◽  
Aluminum Oxide ◽  
High Intensity ◽  
Grinding Wheel ◽  
Grinding Wheels ◽  
Dry Cutting ◽  
Yag Laser ◽  
Laser Dressing ◽  
Preliminary Study ◽  
Set Up

Based on the results of the preliminary study on the influence of high intensity Nd: YAG laser radiation on grinding wheel constituents, an experimental set-up for dressing a grinding wheel was made. Studies were carried out to evaluate the performance of a laser dressed Al2O3 wheel in surface grinding under dry cutting conditions. Results confirmed the viability of this approach and indicated the existence of an optimal dressing condition for good results.

Investigations on Laser Dressing of Grinding Wheels—Part I: Preliminary Study

1989 ◽  
Vol 111 (3) ◽  
pp. 244-252 ◽  
Author(s):  
N. Ramesh Babu ◽  
V. Radhakrishnan ◽  
Y. V. G. S. Murti
Keyword(s):  
Mechanical Properties ◽  
Laser Pulses ◽  
Grinding Wheel ◽  
Thermal And Mechanical Properties ◽  
Grinding Wheels ◽  
Wheel Surface ◽  
Laser Dressing ◽  
Dressing Tool ◽  
Vitrified Bond ◽  
Preliminary Study

Investigations on the use of laser as a dressing tool for grinding wheels have been carried out and the results are reported in a two paper sequence. This paper reports the results of preliminary investigations on grinding wheel materials after laser irradiation. Studies were carried out on the surfaces of aluminum oxide (Al2O3), and silicon carbide (SiC) grains, vitrified bond and also on a sample Al2O3 grinding wheel after irradiating them with high intensity Nd:YAG laser pulses. The results obtained are discussed with reference to the optical, thermal, and mechanical properties of the materials. This paper also includes the studies on the wheel surface topography obtained after laser dressing the wheel with different dressing feed rates.

Optimization and Application of Laser-Dressed cBN Grinding Wheels

2016 ◽  
Vol 1136 ◽  
pp. 90-96 ◽  
Author(s):  
Ali Zahedi ◽  
Bahman Azarhoushang ◽  
Javad Akbari
Keyword(s):  
Environmental Concerns ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Grinding Wheels ◽  
Average Roughness ◽  
Cylindrical Grinding ◽  
Laser Dressing ◽  
Dressing Tool ◽  
Cbn Grinding Wheel ◽  
Spindle Power

Laser-dressing has been shown to be a promising method for overcoming some shortcomings of the conventional methods such as high wear of the dressing tool and its environmental concerns, high induced damage to the grinding wheel, low form flexibility and low speed. In this study, a resin bonded cBN grinding wheel has been dressed with a picosecond Yb:YAG laser. The efficiency of the laser-dressed grinding wheels has been compared with the conventionally dressed and sharpened grinding wheels through execution of cylindrical grinding tests on a steel workpiece (100Cr6). The conventional dressing and sharpening processes have been performed by using a vitrified SiC wheel and vitrified alumina blocks, respectively. By recording the spindle power values along with the surface topography measurements of the ground workpieces and the extraction of two roughness parameters (the average roughness Ra and the average roughness depth Rz), it is possible to provide an assessment of the cylindrical grinding process with different dressing conditions i.e. laser-dressing and conventional dressing. Accordingly, a strategy will be proposed to optimize the cylindrical grinding process with laser-dressed wheels regarding the forces and roughness values.

Laser Profiling of Aluminum Oxide Grinding Wheels

2015 ◽  
Author(s):  
Adrian H. A. Lutey ◽  
Alessandro Fortunato ◽  
Simone Carmignato ◽  
Filippo Zanini ◽  
Alessandro Ascari
Keyword(s):  
Aluminum Oxide ◽  
Normal Incidence ◽  
Separation Distance ◽  
Laser Source ◽  
Grinding Wheel ◽  
Grinding Wheels ◽  
Fine Grain ◽  
X Ray Computed ◽  
Laser Profiling ◽  
Profile Accuracy

Laser profiling experiments are performed at normal incidence on fine grain medium density aluminum oxide grinding wheels with a pulsed nanosecond 1064nm fiber laser source with maximum pulse fluence 369J/cm2. In order to determine the incision depth and ideal laser pass separation distance, laser exposures are first performed on high purity, low porosity aluminum oxide blocks and subsequently analyzed with an optical profiler operating in confocal mode. This ablation data is then applied to path planning for grinding wheel profiling experiments, with division of the necessary removal depth according to the measured incision depth and ideal pass separation distance. X-ray computed tomography is utilized to determine the resulting profile accuracy as a function of process parameters. Test results indicate a maximum profile accuracy in the order of 200μm; however, in order to approach the accuracy of diamond dressing, some two orders of magnitude lower, it is likely that tangential laser incidence is necessary.

scholarly journals Performance of cutting and grinding wheel based on lignin-phenolic resin matrix and aluminum oxide

BioResources ◽  
2017 ◽  
Vol 12 (4) ◽  
pp. 9118-9129
Author(s):  
Jun Zhang ◽  
Jiankun Liang ◽  
Guanben Du ◽  
Xiaojian Zhou ◽  
Hui Wang ◽  
...  
Keyword(s):  
Aluminum Oxide ◽  
Heat Resistance ◽  
Phenol Formaldehyde ◽  
Curing Temperature ◽  
Resin Matrix ◽  
Grinding Wheel ◽  
Formaldehyde Resin ◽  
Grinding Wheels ◽  
Scanning Calorimetry ◽  
Alkali Lignin

Grinding wheels made from an easily-prepared and industrialized thermosetting PFL resin (phenol, formaldehyde, and alkali lignin) with aluminum oxide particles were prepared (i.e., PFL grinding wheel). The mechanical properties of these grinding wheels were characterized by their Brinell hardness, compression strength, and abrasiveness. The curing and heat resistance properties of the PFL resin were studied using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The results indicated that the new PFL resin with 30% of the phenol replaced by alkali lignin exhibited excellent heat resistance. When using alkali lignin to replace a portion of the phenol, the curing temperature of phenol-formaldehyde resin (PF) was increased. Scanning electron microscopy (SEM) of the PFL grinding wheel showed no pores and cracks in the composite when compared to laboratory prepared PF grinding wheels; PFL grinding wheels had high hardness and compression resistance. Furthermore, the PFL grinding wheel exhibited abrasiveness that was comparable to the PF grinding wheel during laboratory tests.

scholarly journals Performance of Norton Quantum Grinding Wheels

2016 ◽  
Vol 686 ◽  
pp. 125-130 ◽  
Author(s):  
Miroslav Neslušan ◽  
Jitka Baďurová ◽  
Anna Mičietová ◽  
Maria Čiliková
Keyword(s):  
Surface Roughness ◽  
Ground Surface ◽  
Bearing Steel ◽  
Grinding Wheel ◽  
Grinding Wheels ◽  
Grinding Forces ◽  
Removal Rates ◽  
Surface Burn ◽  
Conventional Grinding

This paper deals with cutting ability of progressive Norton Quantum grinding wheel during grinding roll bearing steel 100Cr6 of hardness 61 HRC. Cutting ability of this wheel is compared with conventional grinding wheel and based on measurement of grinding forces as well as surface roughness. Results of experiments show that Norton Quantum grinding wheels are capable of long term grinding cycles at high removal rates without unacceptable occurrence of grinding chatter and surface burn whereas application of conventional wheel can produce excessive vibration and remarkable temper colouring of ground surface. Moreover, while Norton Quantum grinding wheel gives nearly constant grinding forces and surface roughness within ground length at higher removal rates, conventional grinding wheel (as that reported in this study) does not.

The Three-Dimensional Surface Topographic Characterisation of Diamond Grinding Wheels

2010 ◽  
Vol 126-128 ◽  
pp. 690-695
Author(s):  
David Lee Butler
Keyword(s):  
Measurement Techniques ◽  
Three Dimensional ◽  
Surface Measurement ◽  
Grinding Wheel ◽  
Profile Measurement ◽  
Detailed Knowledge ◽  
Grinding Wheels ◽  
Diamond Grinding ◽  
Insight Into ◽  
Dimensional Surface

Surface measurement using three-dimensional stylus instruments is a relatively new technique that offers numerous advantages over more traditional profilometry methods. The information generated is, unlike profile measurement, less subjective and more statistical providing additional insight into the surface structure. One application of surface measurement that has encountered problems when using the profilometry method is that of grinding wheel characterisation. The wheel surface texture (topography) and the conditions under which it is generated have a profound effect upon the grinding performance as characterised by the grinding forces, power consumption, temperature, and surface integrity of components. A detailed knowledge of the nature of the topography of the grinding wheel would provide further insight into surface interactions between the wheel and workpiece as well as enabling improved control of the grinding process in general. In this paper four diamond grinding wheels of 91 and 181 micron grit size were subjected to differing dressing conditions to produce varying final wheel topographies. Three-dimensional surface measurement techniques were employed to quantitatively characterise the topographic change and provide an aerial estimation of the number of cutting grains. The results demonstrate that the techniques can distinguish between a worn and dressed wheel. In addition, the parametric values generated from the various surfaces can aid the user in determining when re-dressing is required.

Temperaturanalyse beim Trennschleifen von CFK*/Temperature analysis during the cut-off grinding of CFRP

2017 ◽  
Vol 107 (01-02) ◽  
pp. 87-93
Author(s):  
Y. Babenko ◽  
M. Schneider ◽  
A. Gebhardt
Keyword(s):  
Heat Generation ◽  
Process Parameters ◽  
Cutting Process ◽  
Wird Eine ◽  
Temperature Analysis ◽  
Grinding Wheels ◽  
Dry Cutting ◽  
Empirische Untersuchung

In der vorliegenden Arbeit wird eine empirische Untersuchung zum trockenen Trennschleifen von kohlenstofffaserverstärktem Kunststoff (CFK) vorgestellt. Im Mittelpunkt steht das Ermitteln der Zusammenhänge zwischen Prozessparametern und der Wärmeentstehung sowie resultierenden Temperaturen in der Schleifzone. Darüber hinaus wurde der Verschleiß der Trennschleifscheiben ausgewertet und die Bearbeitungsqualität untersucht.   The presented investigations discuss the dependencies of process parameters and heat generation in the dry cutting process of CFRP. For the cutting process, diamond-tipped grinding wheels are used. For further evaluation additionally the wear of the cutting abrasive and the cutting quality on the workpiece were determined.

Einfluss der Abrichtgrößen beim Schleifen*/Influence of dressing parameters on the grinding process - Systematic research of dressing parameters on workpiece roughness and surface integrity

2016 ◽  
Vol 106 (01-02) ◽  
pp. 44-50
Author(s):  
T. Lierse ◽  
B. Karpuschewski ◽  
T. R. Kaul
Keyword(s):  
Aluminum Oxide ◽  
Surface Integrity ◽  
Cvd Diamond ◽  
Grinding Wheel ◽  
Systematic Research ◽  
Grinding Process ◽  
Wheel Topography ◽  
Grinding Wheel Topography

Dieser Beitrag zeigt, dass die durch die Abrichtparameter erzeugte Schleifscheibentopographie nicht nur die Oberflächengüte des Werkstücks, sondern auch dessen Eigenspannungszustand in der Werkstückrandzone in weiten Grenzen verändert. Die Untersuchungen zum Abrichten von Korundschleifscheiben mit einer CVD-Diamantformrolle stellen den Zusammenhang zwischen dem Abrichten unterschiedlicher Schleifscheiben zur Bauteilqualität in Form der Oberflächenrautiefe und randzonennahen Eigenspannungen her.   The quality of the workpiece rim is changed by every grinding process. The grinding wheel topography created by the dressing process has not only influence on the workpiece roughness but also on the surface integrity. The pointed research using aluminum oxide abrasive wheels dressed by CVD diamond dressing discs shows a correlation between the dressing parameters, the workpiece roughness and the surface integrity.

scholarly journals Use of GnRH for Synchronization of the Follicular Wave in Assisted Reproductive Technologies in Sheep: A Preliminary Study

Animals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1208
Author(s):  
Aina Año-Perello ◽  
Zurisaday Santos-Jimenez ◽  
Teresa Encinas ◽  
Paula Martinez-Ros ◽  
Antonio Gonzalez-Bulnes
Keyword(s):  
Luteinizing Hormone ◽  
Assisted Reproductive Technologies ◽  
Ovarian Response ◽  
Reproductive Technologies ◽  
Estrus Synchronization ◽  
Short Term ◽  
Follicular Wave ◽  
Preliminary Study ◽  
Cost Efficient ◽  
Set Up

The present study aimed to set up a short-term protocol for synchronization of follicular wave emergence in sheep, concomitant with estrus synchronization, which would improve ovarian response in assisted reproductive technologies. Administration of a single GnRH dose, concomitant with the insertion of a progesterone-loaded CIDR device, caused regression of gonadotrophin-dependent follicles ≥4 mm in all the GnRH-treated sheep and in around 80% of the controls treated only with CIDR (p < 0.05). Similar percentages of ewes lost all follicles (around 70%) or only the largest one (around 30%) in both groups. Hence, 54.1% and 70% of the sheep lost all large follicles and initiated a new follicular wave in the control and GnRH groups, respectively (p < 0.05). The remaining sheep showed follicles that were still not dependent of luteinizing hormone (LH). So, in fact, all the sheep had non-dominant follicles after treatment. In conclusion, a treatment including GnRH at CIDR insertion would offer a time- and cost-efficient protocol for inducing follicular turnover and synchronizing a new follicular wave at any stage of the estrous cycle.

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