Study on MQL in Point Grinding Process for Green Manufacturing

2010 ◽  
Vol 97-101 ◽  
pp. 2356-2360 ◽  
Author(s):  
Shu Dong Xiu ◽  
Zhi Jie Geng

In point grinding process, the contact area of point grinding is much smaller than that of conventional cylindrical grinding under same conditions, so the grinding power and heat to measure is lower and the cooling condition is improved obviously. For green manufacturing, the point grinding process has the significance to reduce the consumption of grinding fluid and improve ground surface integrity and greenness. This study analyzes the geometric configuration of the contact area between wheel and workpiece in point grinding process, establishes the geometric and mathematic models of the contact area, and investigates the relations between the grinding parameters and the grinding power by the simulations. The MQL and semi-dry point grinding experiments are performed on the ground surface integrity. These investigations show that the MQL and semi-dry grinding can be achieved in point grinding process under less contact area and higher jet pressure condition for the high greenness demand.

2010 ◽  
Vol 431-432 ◽  
pp. 470-473
Author(s):  
Shi Chao Xiu ◽  
Zhi Jie Geng ◽  
Guang Qi Cai

Due to point contact cause, the point grinding process have the lower grinding power and heat to measure and the better cooling conditions. For green manufacturing, the point grinding process has the significance to reduce the consumption of grinding fluid and improve the ground surface integrity and the process greenness. This study analyzes the geometric configuration of the contact area between the wheel and the workpiece in point grinding process, establishes the geometric and mathematic models of the contact area, and investigates the relations between the grinding parameters. The dry point grinding experiments are performed on the ground surface integrity. These investigations show that the dry grinding can be achieved in point grinding process under less depth of cut and the higher grinding speed for the high machining greenness demand.


2009 ◽  
Vol 407-408 ◽  
pp. 577-581
Author(s):  
Shi Chao Xiu ◽  
Zhi Jie Geng ◽  
Guang Qi Cai

During cylindrical grinding process, the geometric configuration and size of the edge contact area between the grinding wheel and workpiece have the heavy effects on the workpiece surface integrity. In consideration of the differences between the point grinding and the conventional high speed cylindrical grinding, the geometric and mathematic models of the edge contact area in point grinding were established. Based on the models, the numerical simulation for the edge contact area was performed. By means of the point grinding experiment, the effect mechanism of the edge contact area on the ground surface integrity was investigated. These will offer the applied theoretic foundations for optimizing the point grinding angles, depth of cut, wheel and workpiece speed, geometrical configuration and size of CBN wheel and some other grinding parameters in point grinding process.


2008 ◽  
Vol 53-54 ◽  
pp. 209-214 ◽  
Author(s):  
Shi Chao Xiu ◽  
Ya Dong Gong ◽  
Guang Qi Cai

In high and super-high speed grinding process, there is an airflow layer with high speed around the circle edge of the grinding wheel that hinders the grinding fluid into contact layer, namely, the air barrier effect. The speed of airflow layer is directly proportional to the square of the wheel speed. Quick-point grinding is a new type of high and super-high speed grinding process with a point contact zone and less grinding power. The edge effect of the air barrier is weakened because the thin CBN wheel is applied in the process. By the analysis of dynamic pressure and velocity distributions in the airflow layer around the wheel edge, the mathematic models of the flow and jet pressure of grinding fluid for effective supply in the process were established and the process of optimization calculation of the jet nozzle diameter for green manufacturing was also analyzed based on the thermodynamics and the technical character of quick-point grinding process. The quick-point grinding experiment for surface integrity influenced by grinding fluid supply parameters was performed.


Author(s):  
Sawsen Youssef ◽  
Olivier Calonne ◽  
Hédi Hamdi

For complex part geometry, hand grinding is one of finishing and super finishing process the most used in mechanical industry. Surface integrity is today one major concern for industrials. The surface integrity is defined by a set of important characteristics of ground surface as surface geometric parameters (roughness, …), mechanical behaviour of the subsurface (hardness, residual stress, …) and structural changes of the material in the near surface. High heat and pressure, high strain and strain rate observed during hand grinding process, strongly influence surface integrity. Therefore, the surface behaviour, in terms of resistance to corrosion and crack initiation depends on how the process was conducted. The purpose of this study is to understand the effects of thermal and mechanical plastic deformation induced on the surface of components. The action of the disc-grinding wheel on the workpiece is modelled by a moving heat flux on the surface. The challenge is to be able to find the shape and intensity of thermomechanical load entering the workpiece in accordance with the hand disc grinding process and taking into account specific parameters of the process. In a first part, a mechanical description of the action of the disc-wheel on the surface is proposed in order to develop an analytic formulation of the grinding power and the heat flux density. They are function of the disc-grinding wheel velocity, the feed speed and the applied forces. This expression is then used in a finite element modelling to perform thermomechanical simulations of the hand disc-grinding process. In a first stage, heating and cooling are computed. They give maximum temperature reached, temperature gradients and cooling kinematic. In a second stage, thermomechanical computation is conducted in order to compute residual stresses induced by this abrasion process. A discussion based on experimental results obtained by XRD method is then proposed and some local explanation are given on the way the material structure has changed leading to a structural hardening in the 50 first microns beneath the ground surface.


2009 ◽  
Vol 416 ◽  
pp. 13-17 ◽  
Author(s):  
Shi Chao Xiu ◽  
Zhi Jie Geng ◽  
Peng Bo Xiu

Point grinding is a new type of high and super-high speed grinding process with a point contact zone and less grinding force. Because of the lower grinding power, the grinding heat in point grinding process is much less than that of the conventional grinding process. Therefore, the less grinding coolant jet parameters can be used during point grinding process. That is very propitious to the environment and resource, as well as the green manufacturing. Based on the mathematic model of the edge contact area of point grinding, the simulations of the edge contact area with point grinding angles and depth of cut was performed to study the grinding power. In addition, the relations between the grinding power and the depth of cut and vertical grinding angle were investigated. The dynamic pressure and velocity distributions in the airflow layer around the wheel edge were analyzed more by means of experiment. The point grinding experiment for grinding coolant jet parameters was performed.


Author(s):  
Manoj Kumar Sinha ◽  
Rajeshkumar Madarkar ◽  
Sudarsan Ghosh ◽  
Venkateswara Rao Paruchuri

This work explores the improvement in grinding characteristics of Inconel 718 (IN718) using soluble oil under minimum quantity lubrication and liquid nitrogen (LN2) environments. The coolant flow rate in minimum quantity lubrication and LN2 grinding has been regulated through indigenously developed setups. Grinding performance has been studied in terms of on-machine measured grinding forces and centre line average surface roughness ( Ra). The obtained grinding characteristics have been compared with the outcomes under dry and wet grinding. Surface integrity of ground surface, wheel morphology, and chip formation characteristics has been studied using scanning electron microscope, energy dispersive X-ray spectroscopy, and atomic force microscopy. Analysis of variance has been carried out to capture the variability in the experimental data for tangential forces and Ra. The main effect of the factors and their first-order interactions have been considered, and second-order regression equations have been developed using response surface methodology. LN2 grinding has been proved to be more efficient as it yielded lowest grinding forces, least oxidation, minimal ground surface damage and better surface integrity. The occurrence of almost circular chips in dry grinding indicates severe oxidation, whereas small C-type chips formed under minimum quantity lubrication and LN2 conditions indicate effective cooling under these environments. The energy dispersive X-ray spectroscopy analysis of the ground surfaces also supports these results through the occurrence of the highest oxidation in dry grinding. From this work, it has been concluded that LN2 and minimum quantity lubrication grinding offer a clean and effective means to improve grinding performance of IN718 compared to dry and wet grinding.


2010 ◽  
Vol 426-427 ◽  
pp. 49-54 ◽  
Author(s):  
Chang He Li ◽  
Ya Li Hou ◽  
Yu Cheng Ding

Grinding processes are mainly technique employed widely as a finishing process in a variety of materials, such as metals, hardness and brittleness and ductile materials machining to achieve good dimensional and form accuracy of the product with acceptable surface integrity. However, grinding is associated with high specific energy requirements which may be an order higher than that required in other conventional machining processes such as turning, planning, milling etc. Therefore, in grinding process, high grinding zone temperature may lead to thermal damage to the work surface, induces micro-cracks and tensile residual stresses at the ground surfaces, which deteriorate surface quality and integrality of the ground surface. Therefore, grinding fluids are applied in different forms to control such high temperature, but they are ineffective, especially under high speed grinding conditions where the energy of the fluid is not sufficient to penetrate the boundary layer of air surrounding the wheel. Moreover, the conventional flood supply system demands more resources for operation, maintenance, and disposal, and results in higher environmental and health problems. Therefore, there are critical needs to reduce the use of cutting fluid in grinding process, and cryogenic cooling grinding is a promising solution. The work presented in this paper aims at evaluating the grind ability and surface integrity of the nickel base super alloy resulting from the application of cryogenic cooling.


2016 ◽  
Vol 874 ◽  
pp. 362-367
Author(s):  
Xiu Ming Zhang ◽  
Shi Chao Xiu ◽  
Li Juan Liu ◽  
Xiao Liang Shi

Surface integrity of workpiece, especially residual stress, has the significant effects on the precision, the reliability and the fatigue life of the mechanical products. Since the most of final surface integrity of workpiece depends on the grinding process in engineering, this paper analyzed the ground surface residual stress through simulation and experiment. Based on the finite element model, the coupling of thermal mechanical field of plane grinding was simulated. The effects of grinding parameters on residual stress were studied compared to the experiment results. In addition, some measures for reducing the residual tensile stress of workpiece surface in the grinding process were put forwarded.


2011 ◽  
Vol 496 ◽  
pp. 7-12 ◽  
Author(s):  
Takazo Yamada ◽  
Michael N. Morgan ◽  
Hwa Soo Lee ◽  
Kohichi Miura

In order to obtain the effective depth of cut on the ground surface, a new grinding process model taking into account thermal expansions of the grinding wheel and the workpiece, elastic deformations of the grinding machine, the grinding wheel and the workpiece and the wheel wear was proposed. Using proposed model, the effective depth of cut was calculated using measured results of the applied depth of cut and the normal grinding force.


2016 ◽  
Vol 106 (01-02) ◽  
pp. 44-50
Author(s):  
T. Lierse ◽  
B. Karpuschewski ◽  
T. R. Kaul

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.


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