scholarly journals Qualification of the Low-pressure Cold Gas Spraying for the Additive Manufacturing of Copper–Nickel–Diamond Grinding Wheels

2021 ◽  
Author(s):  
W. Tillmann ◽  
J. Zajaczkowski ◽  
I. Baumann ◽  
M. Kipp ◽  
D. Biermann
Keyword(s):  
Thermal Sensitivity ◽  
Continuous Furnace ◽  
Ground Surface ◽  
Low Pressure ◽  
Grinding Wheel ◽  
Hard Material ◽  
Grinding Wheels ◽  
Process Route ◽  
Cold Gas Spraying ◽  
Cold Gas

AbstractGrinding wheels are usually manufactured by powder metallurgical processes, i.e., by molding and sintering. Since this requires the production of special molds and the sintering is typically carried out in a continuous furnace, this process is time-consuming and cost-intensive. Therefore, it is only worthwhile for medium and large batches. Another influencing factor of the powder metallurgical process route is the high thermal load during the sintering process. Due to their high thermal sensitivity, superabrasives such as diamond or cubic boron nitride are very difficult to process in this way. In this study, a novel and innovative approach is presented, in which superabrasive grinding wheels are manufactured by thermal spraying. For this purpose, flat samples as well as grinding wheel bodies were coated by low-pressure (LP) cold gas spraying with a blend of a commercial Cu-Al2O3 cold gas spraying powder and nickel-coated diamonds. The coatings were examined metallographically in terms of their composition. A well-embedded superabrasive content of 12 % was achieved. After the spraying process, the grinding wheels were conditioned and tested for the grinding application of cemented carbides and the topographies of both the grinding wheel and the cemented carbide were evaluated. Surface qualities of the ground surface that are comparable to those of other finishing processes were reached. This novel process route offers great flexibility in the combination of binder and hard material as well as a cost-effective single-part and small-batch production.

Qualification of the Low-Pressure Cold Gas Spraying for the Additive Manufacturing of Copper-Nickel-Diamond Grinding Wheels

2021 ◽  
Author(s):  
W. Tillmann ◽  
J. Zajaczkowski ◽  
I. Baumann ◽  
C. Schaak ◽  
D. Biermann ◽  
...  
Keyword(s):  
Thermal Sensitivity ◽  
Influencing Factor ◽  
Continuous Furnace ◽  
Low Pressure ◽  
Grinding Wheel ◽  
Hard Material ◽  
Grinding Wheels ◽  
Process Route ◽  
Cold Gas Spraying ◽  
Cold Gas

Abstract Grinding wheels are usually manufactured by powder metallurgical processes, i.e. by moulding and sintering. Since this requires the production of special moulds and the sintering is typically carried out in a continuous furnace, this process is time-consuming and cost-intensive. Therefore, it is only worthwhile for medium and large batches. Another influencing factor of the powder metallurgical process route is the high thermal load during the sintering process. Due to their high thermal sensitivity, superabrasives such as diamond or cubic boron nitride are very difficult to process in this way. In this study, a novel and innovative approach is presented, in which superabrasive grinding wheels are manufactured by thermal spraying. For this purpose, flat samples as well as a grinding wheel body were coated by low-pressure (LP) cold gas spraying with a blend of a commercial Cu-Al2O3 cold gas spraying powder and nickel-coated diamonds (8-12 μm). The coatings were examined metallographically in terms of their composition. Afterwards, the grinding wheel was conditioned for the grinding application and the topography was evaluated. This novel process route offers great flexibility in the combination of binder and hard material as well as a costeffective single-part and small-batch production.

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.

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 Multi-Objective Optimization of the Dressing Parameters in Fine Cylindrical Grinding

2019 ◽  
Author(s):  
Irina Stefanova Aleksandrova
Keyword(s):  
Utility Function ◽  
Ground Surface ◽  
Grit Size ◽  
Grinding Wheel ◽  
Multi Objective Optimization ◽  
Optimum Conditions ◽  
Grinding Wheels ◽  
System Parameters ◽  
Synthetic Diamonds ◽  
Generalized Utility

The optimum conditions of dressing grinding wheels determined and recommended in the literature are valid only for particular types and tools of dressing and grinding. In this paper an attempt has been made to optimize the dressing system parameters in fine cylindrical grinding. To define the optimum values of dressing process variables (radial in-feed of diamond roller dresser , dressing speed ratio , dress-out time , diamond roller dresser grit size/grinding wheel grit size ratio , type of synthetic diamonds and direction of dressing) a multi-objective optimization has been performed based on genetic algorithm. In the capacity of optimization parameter a generalized geometric-mean utility function has been chosen which appears to be a complex indicator characterizing the roughness and accuracy of the ground surface, grinding wheel lifetime and the manufacturing net costs of grinding operation. The optimization problem has been solved in the following sequence: 1) a model of the generalized utility function has been created reflecting the complex effect of dressing system parameters; 2) the optimum conditions of uni-directional and counter-directional dressing of aluminium oxide grinding wheels by experimental diamond roller dressers of synthetic diamonds of АС32 and АС80 types and different grit size have been determined at which the generalized utility function has a maximum; 3) Pareto optimum solution has been found (frd=0.2 mm/min; qd=0.8; td=4.65 s; qg=2.56), which guarantees the best combination between roughness and deviation from cylindricity of the ground surface, grinding wheel lifetime and the manufacturing net costs of grinding operation.

T-Dress, A Novel Approach in Dressing and Structuring of Grinding Wheels

2012 ◽  
Vol 565 ◽  
pp. 217-221 ◽  
Author(s):  
Taghi Tawakoli ◽  
Amir Daneshi
Keyword(s):  
Ground Surface ◽  
Decisive Role ◽  
Bearing Steel ◽  
Formation Condition ◽  
Grinding Wheel ◽  
Grinding Wheels ◽  
Grinding Forces ◽  
Wheel Topography ◽  
Grinding Wheel Topography ◽  
Ground Surface Roughness

Since the grinding wheel topography directly influences the grinding forces and material removal mechanism, the dressing of grinding wheels has a decisive role in the desired product quality achievement. A new dressing concept is introduced in this paper in order to reach the optimum chip formation condition. The novel dresser, T-Dress, creates a new structure on the grinding wheel owing to which remarkable reduction in grinding forces occur. These lead to the lower heat generation in the wheel-workpiece contact zone and consequently lower thermal damages. The experiments prove about 40% lower grinding forces in grinding of bearing steel materials, 100Cr6, when dressing with T-Dress compared to the case of dressing with conventional profile rollers with almost no difference in the ground surface roughness values.

scholarly journals An innovative method of applying fluxes using the low-pressure cold gas spraying method

2019 ◽  
Vol 91 (10) ◽  
pp. 17-24
Author(s):  
Tomasz Wojdat ◽  
Marcin Winnicki ◽  
Zbigniew Mirski ◽  
Agata Żuk
Keyword(s):  
Mechanical Properties ◽  
Heat Exchangers ◽  
Low Pressure ◽  
Innovative Method ◽  
Brazed Joints ◽  
Cold Gas Spraying ◽  
Spraying Method ◽  
Cold Gas

In the paper, the results of tests of flux application for aluminum brazing processes using the low-presure cold gas spraying method, are presented. It was pointed out that this method could be used as an alternative to current methods of flux application, among others in the production of aluminum heat exchangers. The results of wettability tests made with braze spreading method on fluxed substrates and metallographic investigations of brazed joints are presented. Good quality of brazed joints without incompatibilities and good mechanical properties have been demonstrated.

Photocatalytic abatement of NOx by C-TiO2/polymer composite coatings obtained by low pressure cold gas spraying

2016 ◽  
Vol 362 ◽  
pp. 274-280 ◽  
Author(s):  
M. Robotti ◽  
S. Dosta ◽  
C. Fernández-Rodríguez ◽  
M.J. Hernández-Rodríguez ◽  
I.G. Cano ◽  
...  
Keyword(s):  
Polymer Composite ◽  
Composite Coatings ◽  
Low Pressure ◽  
Cold Gas Spraying ◽  
Cold Gas

scholarly journals Multi-Objective Optimization of the Dressing Parameters in Fine Cylindrical Grinding

2019 ◽  
pp. 87-102 ◽  
Author(s):  
Irina Stefanova Aleksandrova
Keyword(s):  
Utility Function ◽  
Ground Surface ◽  
Grit Size ◽  
Grinding Wheel ◽  
Multi Objective Optimization ◽  
Optimum Conditions ◽  
Grinding Wheels ◽  
Multi Objective ◽  
Synthetic Diamonds ◽  
Generalized Utility

The optimum conditions for dressing grinding wheels determined and recommended in the literature are valid only for particular types and tools of dressing and grinding. In this paper, an attempt has been made to optimize the dressing process parameters in fine cylindrical grinding. To define the optimum values of the dressing process variables (radial feed rate of diamond roller dresser frd , dressing speed ratio qd , dress-out time td , diamond roller dresser grit size/grinding wheel grit size ratio qg , type of synthetic diamonds and direction of dressing), a multi-objective optimization has been performed based on a genetic algorithm. In the capacity of the optimization parameter, a generalized geometric-mean utility function has been chosen, which appears to be a complex indicator characterizing the roughness and accuracy of the ground surface, the grinding wheel lifetime and the manufacturing net costs of the grinding operation. The optimization problem has been solved in the following sequence: 1) a model of the generalized utility function has been created reflecting the complex effect of the dressing system parameters; 2) the optimum conditions of uni-directional and counter-directional dressing of aluminium oxide grinding wheels by experimental diamond roller dressers of synthetic diamonds of АС32 and АС80 types and different grit size at which the generalized utility function has a maximum have been determined; 3) a Pareto optimum solution has been found (frd = 0.2 mm/min; qd = 0.8; td = 4.65 s; qg = 2.56), which guarantees the best combination between the roughness and the deviation from cylindricity of the ground surface, the grinding wheel lifetime and the manufacturing net costs of the grinding operation.

Effect of Contact Stiffness of Grinding Wheel on Ground Surface Roughness and Residual Stock Removal of Workpiece

2013 ◽  
Vol 797 ◽  
pp. 522-527
Author(s):  
Taisei Yamada ◽  
Hwa Soo Lee ◽  
Kohichi Miura
Keyword(s):  
Surface Roughness ◽  
Contact Stiffness ◽  
Ground Surface ◽  
Grinding Wheel ◽  
Machining Accuracy ◽  
Grinding Wheels ◽  
Residual Stock ◽  
Grinding Operations ◽  
Stock Removal ◽  
Ground Surface Roughness

In the grinding operation, grinding wheels are deformed by grinding forces, so that residual stock removal of the workpiece takes place. Since this residual stock removal of the workpiece causes low machining efficiency and deterioration of machining accuracy, high hardness grinding wheels may be selected in order to obtain high machining efficiency and/or high quality machining accuracy. On the other hand, when grinding operations used by low hardness grinding wheels are carried out, it is well known that ground surface roughness is smaller than in case of higher hardness grinding wheels. From such a viewpoint, this study aims to investigate experimentally the effect of the contact stiffness of grinding wheel on the ground surface roughness and the residual stock removal of the workpiece. Grinding operations were carried out using three grinding wheels which are different hardness type, and ground surface roughness and residual stock removal of the workpiece were measured. The contact stiffness of grinding wheel was calculated by a support stiffness of single abrasive grain and a contact area between grinding wheel and workpiece. Comparing the contact stiffness of grinding wheel with the ground surface roughness and the residual stock removal of the workpiece, it was known that ground surface roughness increases and residual stock removal of workpiece decreases with increaseing the contact stiffness of grinding wheel. From these results, since elastic deformation of the grinding wheel changed depending on the suppot stiffness of single abrasive grain, it was clarified that the ground surface roughness and the residual stock removal of the workpiece were changed by the contact stiffness of grinding wheel.

Study on Edge Contact Area and Surface Integrity of Workpiece in Point Grinding Process

2009 ◽  
Vol 407-408 ◽  
pp. 577-581
Author(s):  
Shi Chao Xiu ◽  
Zhi Jie Geng ◽  
Guang Qi Cai
Keyword(s):  
Surface Integrity ◽  
Contact Area ◽  
High Speed ◽  
Ground Surface ◽  
Depth Of Cut ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Edge Contact ◽  
Cylindrical Grinding ◽  
Theoretic Foundations

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.

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