scholarly journals Forces and Specific Energy of Polyamide Grinding

Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 5041
Author(s):  
Roberto Spina ◽  
Bruno Cavalcante ◽  
Marco Massari ◽  
Roberto Rutigliano
Keyword(s):  
Process Efficiency ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Energy Partition ◽  
Cutting Depth ◽  
Energy Evaluation ◽  
Good Surface ◽  
Custom Made ◽  
Line Temperature

This work investigated the grinding process of reinforced and nonreinforced polyamide materials using an Al2O3 grinding wheel. Samples were ground using a custom-made setup of sensors to evaluate in-line temperature, forces, and power. The surface roughness and images were acquired to assess the quality of the final products. The novelty of the work is to correlate the energy evaluation with the process efficiency during processing. Grinding at high cutting depths achieves good surface quality indicators, such as Ra < 5 μm and Rz < 5 μm. Results also reveal that special attention should be given to the infeed speed when cutting unfilled materials to produce good results. With high values of energy partition, the specific grinding energy stabilizes around 60 J/mm³. Strains must be applied quickly because, to ensure the unfilled materials respond better at this cutting depth, the reinforced materials suffer a slight degradation of quality.

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. &nbsp; 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 Evaluation of Grinding of Unfilled and Glass Fiber Reinforced Polyamide 6,6

Polymers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2288
Author(s):  
Roberto Spina ◽  
Bruno Cavalcante
Keyword(s):  
Surface Roughness ◽  
Glass Fiber ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Fiber Reinforced ◽  
Liquid Coolant ◽  
Part Quality ◽  
Glass Fiber Reinforced ◽  
Process Trends

This paper investigates the grinding process on unreinforced (PA66) and reinforced glass-fiber polyamide 6,6 (PA66 GF30) with Al2O3 and SiC abrasive wheels. Both materials were ground by varying rotations, workpiece infeed speed, depth of cuts for sequential roughing/finishing steps. Dry and liquid coolant conditions were also considered during the grinding process to evaluate the effects on part quality. The surface roughness was used to assess the quality of the final products with several parameter combinations, identifying the induced process trends. The results show that at the end of the finishing step, the surface roughness Rz was lower than 4 μm, attaining the lowest value of 1.34 μm for PA66 specimens. The analysis also suggested the choice of the Al2O3 grinding wheel to reach the lowest Rz values for both materials.

Kinematic Analysis of Face Grinding Process at Lapping Machines

2005 ◽  
Vol 291-292 ◽  
pp. 145-150
Author(s):  
L.X. Cao ◽  
H.J. Wu ◽  
J. Liu
Keyword(s):  
Optimal Path ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Rotational Angle ◽  
Cutting Velocity ◽  
Lapping Machine ◽  
Cutting Path ◽  
Face Grinding ◽  
Relative Motions

The precise face grinding and lapping technology with abrasive or abrasive tool has been widely used in the field of the precise manufacture and ultraprecise manufacture. It has become an essential technology in the manufacture of many components. The planetary lapping machine is typical equipment for face grinding or lapping process. And the relative motions between the workpieces and grinding wheel will affect the formation of wear profiles of the tools, furthermore, the work result will be affected directly by the cutting path of this relative motions. In this paper, the kinematic principle of face grinding process on lapping machines has been analyzed. By means of the concept of pitch point and pitch circles, the complicated grinding process has been converted into two kinds of rotations with the fixed center distance. Two kinds of path curves, i.e. workpiece against grinding wheel and grinding wheel against workpiece, and their relations are analyzed. The geometrical analyses and the manufacture quality of the workpiece are linked with the aid of the cutting velocity, the range of the rotational angle of the cutting traces and the rate of the change of the rotational angle with time. The optimal path curve and kinematic parameters are achieved, and these results are corresponding to the experimental results.

A Heat Transfer Model of Grinding Process Based on Energy Partition Analysis and Grinding Fluid Cooling Application

2017 ◽  
Vol 139 (12) ◽  
Author(s):  
Guoxu Yin ◽  
Ioan D. Marinescu
Keyword(s):  
Heat Transfer ◽  
Contact Area ◽  
Frictional Resistance ◽  
Heat Transfer Model ◽  
Heat Energy ◽  
Grinding Wheel ◽  
Transfer Model ◽  
Grinding Process ◽  
Energy Partition ◽  
Grinding Fluid

In the grinding process, high temperature in grinding area is generated by the frictional resistance between workpiece and abrasive grains on the grinding wheel cylindrical surface. Grinding fluid application is an optimal option to reduce the thermal effect and crack on the workpiece ground surface. In this paper, a grinding process heat transfer model with various grinding fluid application is introduced based on computational fluid dynamics (CFD) methodology. The effect of specific heat, viscosity, and surface tension of grinding fluid are taken into account. In the model, the grinding contact area is considered as a heating resource. Most of the heat energy is conducted into the workpiece. The rest of the energy is taken away by the grinding wheel, grinding fluid, and chips. How many percentage of the generated heat is conducted into the workpiece is a key issue, namely, the energy partition ratio ε. An energy partition equation is introduced in this paper with the cooling effect of different grinding fluid. Generated heat energy based on the calculation from energy partition equation is applied on the grinding contact area in the heat transfer model.

scholarly journals INFLUENCE OF THE GEOMETRIC CHARACTERISTICS OF THE DISCONTINUOUS PROFILE WORKING SURFACES OF ABRASIVE WHEELS FOR PRECISION AND TEMPERATURE WHEN GRINDING

2021 ◽  
pp. 115-125
Author(s):  
Oleksiy Yakimov ◽  
Liubov Bovnegra ◽  
Vladimir Tonkonogyi ◽  
Vladyslav Vaysman ◽  
Victor Strelbitskyi ◽  
...  
Keyword(s):  
Surface Layer ◽  
Heat Stress ◽  
Elastic System ◽  
Dynamic Interaction ◽  
Grinding Wheel ◽  
Stable Operation ◽  
Grinding Process ◽  
Abrasive Wheel ◽  
Working Surface

Grinding is the most common finishing method for hardened steel parts. Grinding is accompanied by a large heat release in the cutting area, under the influence of which structural changes appear in the thin surface of the processed parts, tensile stress and even microcracks, which significantly reduce the operational reliability of machines that include these parts. The use of abrasive wheels with an intermittent working surface makes it possible to reduce the temperature in the area of contact of abrasive grains with the material of the workpiece and, as a consequence, stabilize the quality of the surface layer of the workpieces. High-frequency vibrations in the elastic system of the machine, accompanying the work of an intermittent wheel, are a positive factor that reduces the energy consumption of the grinding process. However, under certain conditions of dynamic interaction of the tool with the workpiece, parametric resonance may occur, which worsens the geometric and physical-mechanical parameters of the quality of the surface layer of the processed part. The aim of the work is to realize the possibility of predicting the quality parameters of the surface layer of parts during intermittent grinding by studying the influence of the design features of the macrotopography of the working surface of abrasive wheels and processing modes on the nature of the dynamic interaction of the tool with the workpiece and the heat stress in the cutting area. It was found that the parametric vibrations of the elastic system of the machine tool can be shifted to a more stable area, due to an increase in the number of interruptions of the working surface of the abrasive wheel with a constant ratio of the length of the protrusions and depressions. The increase in the number of breaks on the wheel also contributes to a decrease in temperature in the cutting area. It was found that to maintain the stable operation of the elastic system of the machine, it is necessary to reduce the number of cavities on the grinding wheel with an increase in the cutting speed. However, both of these actions are accompanied by an increase in the heat stress of the grinding process. It has been experimentally established that for ordinary (pendulum) grinding, it is possible to achieve an increase in processing productivity by increasing the speed of the longitudinal movement of the table.

scholarly journals A RESEARCH ON MULTI-OBJECTIVE OPTIMIZATION OF THE GRINDING PROCESS USING SEGMENTED GRINDING WHEEL BY TAGUCHI-DEAR METHOD

2021 ◽  
pp. 67-77
Author(s):  
Do Duc Trung ◽  
Nhu-Tung Nguyen ◽  
Dung Hoang Tien ◽  
Ha Le Dang
Keyword(s):  
Surface Roughness ◽  
Taguchi Method ◽  
Feed Rate ◽  
Research Direction ◽  
Grinding Wheel ◽  
Cylinder Surface ◽  
Grinding Process ◽  
Cutting Depth ◽  
Technology System ◽  
Input Parameters

In this study, the mutil-objective optimization was applied for the surface grinding process of SAE420 steel. The aluminum oxide grinding wheels that were grooved by 15 grooves, 18 grooves, and 20 grooves were used in the experimental process. The Taguchi method was applied to design the experimental matrix. Four input parameters that were chosen for each experiment were the number of grooves in cylinder surface of grinding wheel, workpiece velocity, feed rate, and cutting depth. Four output parameters that were measured for each experimental were the machining surface roughness, the system vibrations in the three directions (X, Y, Z). The DEAR technique was applied to determine the values of the input parameters to obtaine the minimum values of machining surface roughness and vibrations in three directions. By using this technique, the optimum values of grinding wheel groove number, workpiece velocity, feed-rate, cutting depth were 18 grooves, 15 m/min, 2 mm/stroke, and 0.005 mm, respectively. The verified experimental was performed by using the optimum values of input parameters. The validation results of surface roughness and vibrations in X, Y, Z directions were 0.826 (µm), 0.531 (µm), 0.549 (µm), and 0. 646 (µm), respectively. These results were great improved in comparing to the normal experimental results. Taguchi method and DEAR technique can be applied to improve the quality of grinding surface and reduce the vibrations of the technology system to restrain the increasing of the cutting forces in the grinding process. Finally, the research direction was also proposed in this study

Effect of the Grinding Oil Type on CBN Grinding Wheels Performance

2009 ◽  
Author(s):  
Taghi Tawakoli ◽  
Abdolreza Rasifard ◽  
Alireza Vesali
Keyword(s):  
Heat Resistance ◽  
Surface Quality ◽  
Grinding Wheel ◽  
Work Piece ◽  
Grinding Process ◽  
Grinding Wheels ◽  
Grinding Forces ◽  
Vitrified Cbn ◽  
Oil Type

The efficiency of the grinding process highly depends on the coolant lubricant used. In grinding with CBN grinding wheels grinding oils are used increasingly. In the last decade new grinding oils based on different oil types are brought into the market, whose effect on the CBN grinding wheels performance until now not sufficiently been investigated. The Institute of Grinding and Precision Technology (KSF) investigated the influence of four different grinding oils on the performance of vitrified CBN grinding while grinding of 100Cr6 (M.-No. 1.3505), which is a heat-treatable steel with a very good grindability, and Nimonic A80, which is a difficult to grind heat-resistance superalloy. The obtained results show that the performance of the vitrified CBN grinding wheels—while using grinding oil as coolant lubricant—regarding the quality of the work piece surface, the grinding forces as well as the wear of the grinding wheel, highly depend on the viscosity of the grinding oil. Moreover, the results show that the surface quality and the grinding forces while using different grinding oils depend significantly on the work piece material.

scholarly journals Automating the Mold-Material Grinding Process

2019 ◽  
Vol 13 (6) ◽  
pp. 722-727
Author(s):  
Takekazu Sawa ◽  
Keyword(s):  
Diamond Wheel ◽  
Mold Material ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Bending Vibrations ◽  
Bending Vibration ◽  
Abrasive Grains ◽  
Metal Materials ◽  
Vibration Noise

Grinding is difficult to control because abrasive grains are scattered randomly on the surface of the grinding wheel, and the quality of the grinding work is strongly dependent on the skill of the operator. Therefore, automation and optimization technologies should be established immediately for grinding, along with other machining work. From this perspective, we observed the bending vibrations of a diamond wheel during a grinding project and developed a technique to identify the grinding condition by using a microphone to measure the small noises from the vibration (called bending-vibration noise in this paper). In this paper, we report the application of the technique to an ordinary grinding wheel, and our attempt to automate the grinding work of STAVAX and SKD11 metal materials.

scholarly journals Investigation of the Effect of Vibration Characteristics on the Grinding Performance of Aero-Engine Blade Tip

2021 ◽  
Author(s):  
Wei Li ◽  
Qidi Chen ◽  
Jian Wu ◽  
Mingjia Liu ◽  
Yinghui Ren ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Great Influence ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Aero Engine ◽  
Engine Blade ◽  
Blade Tip ◽  
The Difference

Abstract The machining quality of the blade tip has a great influence on the service performance and life of the aero-engine blade. The recent paper investigates the effect of vibration during the grinding process of the GH4169 nickel-based superalloy blade tip. Moreover, this paper proposes a theoretical model to link the unbalance of the grinding wheel, the vibration, and the surface topography characteristics of the blade. The results show that the blade vibration during grinding and the resulting non-linear change of the grinding depth could reduce the surface quality of the blade tip, and lead to differences in the surface quality of the blade tip in different areas, where the surface roughness in the entry area zone I is the largest, in the exit area zone III is the second largest, and the intermediate area zone III is the smallest. Grinding depth has a greater impact on the difference of the surface quality in the blade tip grinding process, especially when the grinding depth is greater than 4 μm, the difference of surface roughness increases significantly. On the other hand, the feed rate has little effect on the difference in surface quality. Adding damping block can reduce the surface roughness of the blade tip, however, it does not reduce the difference in surface quality.

scholarly journals New Abrasive Materials and Their Influence on the Surface Quality of Bearing Steel After Grinding

10.14311/1598 ◽  
2012 ◽  
Vol 52 (4) ◽  
Author(s):  
Ondrej Jusko
Keyword(s):  
Surface Quality ◽  
Bearing Steel ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Grinding Wheels ◽  
Abrasive Material ◽  
Abrasive Grains ◽  
Measurement Results ◽  
New Type

This paper focuses on the influence of various types of abrasive grains on cutting properties during the grinding process for bearing steel. In this experiment, not only conventional super-hard abrasive materials but also a new type of abrasive material were employed in grinding wheels. The measurement results were compared, and an evaluation was made of the cutting properties of the new abrasive material. The options were then evaluated for their practical applicability. The measurement results indicated that a grinding wheel with Abral and SG grains is the most suitable for grinding hardened bearing steel in order to achieve the best roughness and geometrical accuracy.

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