scholarly journals Laser Assisted Micro Grinding of Titanium

2021 ◽  
Author(s):  
Ashish Kumar Sahu ◽  
Sunil Jha
Keyword(s):  
Surface Roughness ◽  
Surface Finish ◽  
Laser Power ◽  
Tangential Force ◽  
Material Surface ◽  
Grinding Wheel ◽  
Micro Channel ◽  
Grinding Forces ◽  
Scanning Velocity ◽  
Pulsed Fiber Laser

Abstract Laser assisted micro-grinding (LAMG) is an emerging area of research in the field of high-quality micro-job fabrication and performance improvement. Conventional micro grinding (CMG) by micro pencil grinding tool suffers drawbacks such as tool deflection, higher cutting force and poor surface finish. In the present work, authors have attempted to investigate the performance of LAMG and CMG in the fabrication of micro-channel on Titanium material. Surface of workpiece was structured with the help of air assisted nanosecond-pulsed fiber laser scanning prior to the CMG at the different values of laser power by keeping scanning velocity constant. During the study, the CMG forces were recorded and after the processes surface roughness of the fabricated microchannels was measured. Results have shown reduction in the magnitude of the normal and tangential force by 31 % and 44 %, respectively, in LAMG compared to the CMG. In addition to that better surface finish was observed in LAMG than CMG. The surface roughness of micro-channel and grinding forces were found to be dependent on the power density of laser. Increase in the laser power deteriorates the surface finish and reduces the magnitude of grinding forces. High grinding forces in the CMG led to the dynamic deflection of the grinding wheel which produced the vibration in the process. The excessive vibration in CMG processes exploited the surface finish of the micro-channel. Such vibration was not observed on the LAMG process; as a result, better dimensional accuracy and surface finish of the channel was found.

Effects of Rotary Dressing on Grinding Wheel Performance

1978 ◽  
Vol 100 (3) ◽  
pp. 297-302 ◽  
Author(s):  
T. Murray ◽  
S. Malkin
Keyword(s):  
Surface Roughness ◽  
Surface Finish ◽  
Direct Relationship ◽  
Grinding Wheel ◽  
Grinding Forces ◽  
Trade Off ◽  
Flat Area ◽  
Grinding Performance

An investigation is described of the effects of rotary dressing on grinding wheel performance. Grinding performance is evaluated mainly in terms of the grinding forces and surface finish. It is demonstrated that the magnitudes of the grinding forces can be attributed to differences in the size of the wear flat area obtained by the various rotary dressing conditions. For finer dresser infeeds and greater differences between the peripheral velocities of the dresser and the grinding wheel, bigger grinding forces and smoother surfaces are obtained. A direct relationship is obtained between the grinding performance and the dressing interference angle, a larger angle resulting in smaller grinding forces and rougher surfaces. This leads to a trade-off relationship between grinding forces and surface roughness which characterizes the rotary dressing process.

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 mechanism of process parameters influencing the AlSi10Mg side surface quality fabricated via laser powder bed fusion

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Shimin Dai ◽  
Hailong Liao ◽  
Haihong Zhu ◽  
Xiaoyan Zeng
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Process Parameters ◽  
Laser Power ◽  
Side Surface ◽  
Laser Powder Bed Fusion ◽  
Scanning Velocity ◽  
Content Type ◽  
Powder Bed

Purpose For the laser powder bed fusion (L-PBF) technology, the side surface quality is essentially important for industrial applicated parts, such as the inner flow parts. Contour is generally adopted at the parts’ outline to enhance the side surface quality. However, the side surface roughness (Ra) is still larger than 10 microns even with contour in previous studies. The purpose of this paper is to study the influence of contour process parameters, laser power and scanning velocity on the side surface quality of the AlSi10Mg sample. Design/methodology/approach Using L-PBF technology to manufacture AlSi10Mg samples under different contour process parameters, use a laser confocal microscope to capture the surface information of the samples, and obtain the surface roughness Ra and the maximum surface height Rz of each sample after analysis and processing. Findings The results show that the side surface roughness decreases with the increase of the laser power at the fixed scanning velocity of 1,000 mm/s, the side surface roughness Ra stays within the error range as the contour velocity increases. It is found that the Ra increases with the scanning velocity increasing and the greater the laser power with the greater Ra increases when the laser power of contour process parameters is 300 W, 350 W and 400 W. The Rz maintain growth with the contour scanning velocity increasing at constant laser power. The continuous uniform contour covers the pores in the molten pool of the sample edge and thus increase the density of the sample. Two mechanisms named “Active adhesion” and “Passive adhesion” cause sticky powder. Originality/value Formation of a uniform and even contour track is key to obtain the good side surface quality. The side surface quality is determined by the uniformity and stability of the contour track when the layer thickness is fixed. These research results can provide helpful guidance to improve the surface quality of L-PBF manufactured parts.

scholarly journals An Evaluation of the use of Laser-Vibration Melting to Increase the Surface Roughness of Metal Objects

2015 ◽  
Vol 60 (1) ◽  
pp. 33-39 ◽  
Author(s):  
B. Grabas
Keyword(s):  
Surface Roughness ◽  
Laser Beam ◽  
Laser Power ◽  
Surface Structures ◽  
Scanning Velocity ◽  
New Approach ◽  
Practical Applications ◽  
Microscopic Evaluation ◽  
Heating Surfaces ◽  
Laser Beam Scanning

Abstract This paper presents preliminary, experimental results of a new, hybrid method of increasing the surface roughness of metal objects. In this new approach, metal objects are melted with a mobile laser beam while they are being rotated. A vibration generator provides circular vibrations with an amplitude of 3 mm, and the vibration plane is perpendicular to the moving laser beam. The melting tests were performed using flat carbon steel samples at a predetermined frequency of circular vibrations. The effects of laser power and laser beam scanning velocity on the melted shapes were studied. All laser melting procedures were performed at a vibration frequency of 105 Hz. The melted samples were subjected to microscopic evaluation and the Ra parameter, which characterises mean roughness, was measured using a profilometer. Melting metal samples with physically smooth surfaces (Ra = 0.21 µm) resulted in surface structures of varied roughness values, with Ra ranging from 5 µm to approximately 58 µm. The studies were undertaken to employ this technology for the purpose of passive heat exchange intensification of heating surfaces in practical applications.

Characterizing the Effect of Laser Power Density on Microstructure, Microhardness, and Surface Finish of Laser Deposited Titanium Alloy

2013 ◽  
Vol 135 (6) ◽  
Author(s):  
Rasheedat M. Mahamood ◽  
Esther T. Akinlabi ◽  
Mukul Shukla ◽  
Sisa Pityana
Keyword(s):  
Surface Roughness ◽  
Titanium Alloy ◽  
Power Density ◽  
Surface Finish ◽  
Laser Power ◽  
Optical Microscope ◽  
Laser Power Density ◽  
Grain Structure ◽  
Selection Of

This paper reports the effect of laser power density on the evolving properties of laser metal deposited titanium alloy. A total of sixteen experiments were performed, and the microstructure, microhardness and surface roughness of the samples were studied using the optical microscope (OP), microhardness indenter and stylus surface analyzer, respectively. The microstructure changed from finer martensitic alpha grain to coarser Widmastätten alpha grain structure as the laser power density was increased. The results show that the higher the laser power density employed, the smoother the obtained surface. The microhardness initially increased as the laser power density was increased and then decreased as the power density was further increased. The result obtained in this study is important for the selection of proper laser power density for the desired microstructure, microhardness and surface finish of part made from Ti6Al4V.

Cylindrical Grinding by Structured Wheels

2016 ◽  
Vol 874 ◽  
pp. 101-108 ◽  
Author(s):  
Amir Daneshi ◽  
Bahman Azarhoushang
Keyword(s):  
Surface Roughness ◽  
Ground Surface ◽  
Promising Method ◽  
Grinding Wheel ◽  
Grinding Wheels ◽  
Grinding Forces ◽  
Cylindrical Grinding ◽  
Dry Grinding

Structuring of the grinding wheels is a promising method to reduce the forces involved in grinding, especially during dry grinding. In this paper, one of the methods of grinding wheel structuring is presented. The structuring process was modeled to find the corresponding dressing parameters for the desired structure dimensions. The cylindrical grinding operation with the structured wheels was simulated to produce a spiral free ground surface. Afterwards, the dry grinding experiments with the structured and non-structured wheels were carried out to evaluate the efficiency of the structured wheels. The results revealed that the grinding forces can be reduced by more than 50% when the grinding wheels are structured, while the surface roughness values increase by 80%.

scholarly journals Optimization of parameters in cylindrical and surface grinding for improved surface finish

2018 ◽  
Vol 5 (5) ◽  
pp. 171906 ◽  
Author(s):  
Dinesh Kumar Patel ◽  
Deepam Goyal ◽  
B. S. Pabla
Keyword(s):  
Surface Roughness ◽  
Surface Integrity ◽  
Surface Finish ◽  
Surface Characteristics ◽  
Surface Grinding ◽  
Depth Of Cut ◽  
Grinding Wheel ◽  
Cylindrical Grinding ◽  
Grinding Parameters ◽  
Wheel Material

Surface integrity has attracted the attention of researchers for improving the functional performance of engineering products. Improvement in surface finish, one of the important parameters in surface integrity, has been attempted by researchers through different processes. Grinding has been widely used for final machining of components requiring smooth surfaces coupled with precise tolerances. Proper selection of grinding wheel material and grade with grinding parameters can result in an improved surface finish and improved surface characteristics. The present work reports the study of the effect of grinding parameters on surface finish of EN8 steel. Experiments were performed on surface grinding and cylindrical grinding for optimization of grinding process parameters for improved surface finish. Grinding wheel speed, depth of cut, table feed, grinding wheel material and table travel speed for surface grinding operation, and work speed for cylindrical grinding operation were taken as the input parameters with four types of grinding wheels (Al 2 O 3 of grades K and L, and white alumina of grades J and K). The surface roughness was taken as an output parameter for experimentation. The grinding wheel material and grade have been observed to be the most significant variables for both cylindrical grinding and surface grinding. Surface roughness in the case of surface grinding is better compared to that of cylindrical grinding, which can be attributed to vibrations produced in the cylindrical grinding attachment. Surface roughness ( R a ) values of 0.757 µm in cylindrical grinding and 0.66 µm in surface grinding have been achieved.

Design of Surface Finish Using Synchronous Process of Grinding and Electrochemical Finishing

2007 ◽  
Vol 359-360 ◽  
pp. 259-263
Author(s):  
Pai Shan Pa
Keyword(s):  
Surface Roughness ◽  
Flow Rate ◽  
Surface Finish ◽  
Feed Rate ◽  
Rotational Speed ◽  
Machining Process ◽  
Grinding Wheel ◽  
High Rotational Speed ◽  
Plate Electrode ◽  
Electrochemical Finishing

In order to elevate the efficiency of the surface finish to reach the fast improvement of the surface roughness of the workpiece, so as to reduce the residual stress on the surface efficiently. The present study discusses the surface after traditional machining, of which the plane surface used a design of finish tool includes an electrode and a nonconductive grinding wheel to execute the synchronous process of grinding and electrochemical finishing. The electrode form and the machining process are obviously different from electrochemical grinding (ECG). In the experiment, the design electrode is used with continuous and pulsed direct current. The controlled factors include die material, and chemical composition and concentration of the electrolyte. The experimental parameters are flow rate of electrolytes, position of plate electrode, electrode thickness, electrode rotational speed, electrical current rating, feed rate of workpiece, and pulsed period. The experimental results show that the supply of current rating is near concern with the position and thickness of the plate electrode. The use of large electrolytic flow rate and thick electrode is advantageous to the finish effect. High rotational speed of finish tool produces better polishing. The finishing effect is better with longer off-time because discharge of polishing dregs becomes easier. Higher current rating with quicker workpiece feed rate effectively reaches the fast improvement of the surface roughness of the workpiece is recommend in current study.

A Study on Ultrasonic Assisted Grinding of Nickel-Based Superalloys

2013 ◽  
Vol 797 ◽  
pp. 356-361
Author(s):  
Wen Qing Song ◽  
Yong Bo Wu ◽  
Jian Guo Cao ◽  
Jing Ti Niu
Keyword(s):  
Surface Roughness ◽  
Grinding Wheel ◽  
Grinding Forces ◽  
Work Surface ◽  
Ultrasonic Assisted Grinding ◽  
Nickel Based Superalloy ◽  
Ultrasonic Assisted ◽  
The Face ◽  
Cbn Grinding Wheel ◽  
Face Grinding

Ultrasonic assisted grinding experiments were carried out to evaluate the effects of the ultrasonic vibration (UV) on the face grinding characteristics of nickel based superalloy of Rene77. In experiments, an electroplated cBN grinding wheel was ultrasonically vibrated dominantly along its axis. The experimental results indicated that the X-axis and Y-axis components of grinding forces with UV were smaller by 44.5% and 31.6%, respectively, than those without UV. The usual fractures and debris on the surface of workpiece disappeared and the work-surface roughness Ra was decreased by 42.3% once the UV was applied. The abrasion of the grinding wheel without UV is more serious than that with UV.

Effects of Parameters on Surface Roughness of Metal Parts by Selective Laser Melting

2013 ◽  
Vol 834-836 ◽  
pp. 872-875 ◽  
Author(s):  
Qun Qin ◽  
Guang Xia Chen
Keyword(s):  
Surface Roughness ◽  
Power Density ◽  
Selective Laser Melting ◽  
Laser Power ◽  
Processing Parameters ◽  
Laser Power Density ◽  
Laser Melting ◽  
Scanning Velocity ◽  
Metal Parts ◽  
Overlap Ratio

The primary goal of this research is the effects of laser process parameters on surface roughness of metal parts built by selective laser melting. The main processing parameters used to control the surface roughness of melted layers are laser power, scanning velocity and overlap ratio. In our work, an orthogonal experimental design was employed to find the changing rules of the surface roughness through changing SLM processing parameters. The results show that the overlap ratio is the most important factor to affect the surface roughness. When the overlap ratio is below 50%, the surface roughness value of melted layers will decrease with laser power density increasing. When the overlap ratio is higher than or equal to 50%, the surface roughness value increases with the laser power density increasing. The optimal parameters of laser power 143W, scanning velocity 5m/min and overlap ratio 30% can be used to achieve melted layers with the best surface quality in our experiments, and the roughness value increases with slicing thickness increasing and the surface bias angle decreases.

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