Effect of Complex Electrodischarge Grinding for Electrically Conductive PCD

2011 ◽  
Vol 325 ◽  
pp. 276-281 ◽  
Author(s):  
Manabu Iwai ◽  
Shinichi Ninomiya ◽  
Kiyoshi Suzuki
Keyword(s):  
High Efficiency ◽  
Low Cost ◽  
Surface Condition ◽  
High Hardness ◽  
Grinding Wheel ◽  
Wheel Wear ◽  
Electrically Conductive ◽  
Grinding Method ◽  
Conventional Grinding ◽  
Composite Diamond

Polycrystalline Composite Diamond (PCD) is excellent in chipping resistance despite its very high hardness. However, it is not easy to EDM or grind PCD. To realize high efficiency and high quality processing of PCD simply and at low cost, the authors devised new PCD (EC-PCD) by using electrically conductive diamond particles and applied a complex electrodischarge grinding method. In this study, investigation is made on effective grinding condition to realize high efficiency, low and stable grinding force and low wheel wear in complex electrodischarge grinding. As a result, superior grinding property was obtained when the grinding wheel was set at minus polarity, and set peak current of iP = 4 and 6 A was applied. Furthermore it also became clear that additional conventional grinding process followed after complex electrodischarge grinding improved the surface condition.

Complex Grinding Assisted with Electrical Discharge Machining for Electrically Conductive PCD

2010 ◽  
Vol 126-128 ◽  
pp. 591-596 ◽  
Author(s):  
Manabu Iwai ◽  
Shinichi Ninomiya ◽  
Gaku Sugino ◽  
Kiyoshi Suzuki
Keyword(s):  
Surface Finish ◽  
Electrical Discharge ◽  
Material Removal ◽  
High Efficiency ◽  
Electrical Discharge Machining ◽  
Grinding Force ◽  
Wheel Wear ◽  
Electrically Conductive ◽  
Composite Diamond

A new PCD material named EC-PCD (Electrically conductive polycrystalline composite diamond), which consists of electrically conductive diamond grits, has recently been developed. This paper deals with an investigation of a complex grinding assisted with electrical discharge machining (EDM) to realize high efficiency, low and stable grinding force and low wheel wear for the new EC-PCD. The effect of complex grinding assisted with EDM is compared experimentally with the standard PCD (S-PCD). The result shows that, in the complex grinding, lower and more stable grinding force is realized thanks to the material removal action in EDM and that lower wheel wear and better surface finish are attained, just when the EC-PCD is selected as a workpiece.

A Study on Electrolytic In-Process Dressing (ELID) Grinding of Sapphire With Acoustic Emission

2009 ◽  
Author(s):  
Peidong Han ◽  
Ioan D. Marinescu ◽  
Anil Srivastava
Keyword(s):  
Acoustic Emission ◽  
Surface Finish ◽  
High Efficiency ◽  
High Hardness ◽  
Processing Parameters ◽  
Great Promise ◽  
Grinding Wheel ◽  
Wheel Wear ◽  
Elid Grinding ◽  
Wheel Loading

Single crystal sapphire is of significant interest due to its combination of excellent optical, electrical, and mechanical properties. However, fine grinding of sapphire is quite challenging because of its high hardness and low fracture toughness, making it sensitive to cracking. Wheel loading is a common problem in conventional grinding of hard and brittle materials. ELID grinding shows great promise in achieving a mirror surface finish at a relatively high efficiency. ELID grinding of sapphire was investigated using acoustic emission. The effects of processing parameters on surface finish and acoustic emission signals were evaluated. Correlations were found among the dressing current intensity, surface finish and acoustic emission signals. A smoother surface was obtained using a higher dressing current at the cost of a higher wheel wear rate. The wheel wear mechanism in ELID grinding of sapphire was dominated by bond fracture because the bond strength is reduced by electrolysis. Results indicate that the acoustic emission technique has the potential to be used for monitoring ELID grinding process, detecting the condition of the grinding wheel, and investigating the mechanisms of ELID grinding.

Processing EC-PCD by Constant-Force Grinding Assisted with EDM

2010 ◽  
Vol 126-128 ◽  
pp. 645-650
Author(s):  
Gaku Sugino ◽  
Manabu Iwai ◽  
Tadakazu Sano ◽  
Shinichi Ninomiya ◽  
Kiyoshi Suzuki
Keyword(s):  
Electrical Discharge ◽  
Material Removal ◽  
High Efficiency ◽  
Electrical Discharge Machining ◽  
Removal Rate ◽  
Surface Condition ◽  
Grinding Force ◽  
Constant Force ◽  
Wheel Wear ◽  
Electrically Conductive

A new PCD (electrically conductive PCD: EC-PCD) consisting of electrically conductive diamond particles has recently been developed. The authors have proposed a complex grinding assisted with electrical discharge machining (EDM) where discharge machining and grinding are used in combination during material removal to realize high efficiency, low and stable grinding force and low wheel wear for the EC-PCD. In this study, the effect of constant-force grinding in a complex grinding assisted with electrical discharge machining of EC-PCD was investigated. As a result, it was found that higher material removal rate, higher grinding ratio and better surface condition were obtained on EC-PCD compared with standard PCD (S-PCD) in the constant-force grinding.

Machining Mechanism of Abrasive Water Jet on Ceramics

2010 ◽  
Vol 426-427 ◽  
pp. 212-215 ◽  
Author(s):  
Feng Lian Zhang
Keyword(s):  
High Efficiency ◽  
Low Cost ◽  
Brittle Materials ◽  
High Hardness ◽  
Ceramic Materials ◽  
Water Jet ◽  
Abrasive Water Jet ◽  
Engineering Ceramics ◽  
Abrasive Water Jet Machining ◽  
Complex Process

Engineering ceramics feature resistance to high temperature, corrosion, wear and hot impact. However, it is difficult to machine this material in conventional machining methods because of its high hardness and brittleness as well as inconductivity, thus restricting its application area. In recent years, more and more importance has been attached to the new machining method of engineering ceramics, i.e. abrasive water-jet. Feature high efficiency and low cost, the method can be used to process the products of complex shape. However, abrasive water-jet machining of advanced ceramics is a very complex process. The effect of machining on brittle materials, and advanced ceramic materials in particular, have not yet been very well understood. The present research investigates the effect of abrasive water-jet machining on ceramics. The study will increase the general understanding of the machining phenomena for more successful application of abrasive water-jet machining on brittle materials.

Evaluation of the Working Surface of the Grinding Wheel Using Speckle Image Analysis

2015 ◽  
Author(s):  
Arunachalam Narayanaperumal ◽  
Vijayaraghavan Lakshmanan
Keyword(s):  
Surface Quality ◽  
Surface Condition ◽  
Grinding Wheel ◽  
Optical Parameters ◽  
Wheel Surface ◽  
Wheel Wear ◽  
Speckle Image ◽  
Periodic Monitoring ◽  
Grinding Machine

The surface quality of the ground components mainly depends on the surface condition of the grinding wheel. The surface condition of the grinding wheel changes with grinding time due to wheel wear and loading. The excessive wear and loading increases the cutting force and the temperature. This in turn affects the quality of the produced component. Hence periodic monitoring of the grinding wheel surface is essential to avoid the production of the defective components. In this paper, an attempt is made to study the changes in the grinding wheel surface condition using the laser scattered images. The simple speckle imaging arrangement is fabricated and fitted into the grinding machine to capture the images of the grinding wheel after each 100 passes. The fresh wheel expected to scatter more light due to higher roughness and porosity. On the other hand, the completely glazed and worn-out wheel scatters the light less due to smoother surface. Thus, speckle image intensity distribution captures the changes in the grinding wheel surface condition. The optical parameters evaluated from the speckle images clearly indicating the changes in the grinding wheel condition. This method can be utilized to evaluate the grinding wheel condition to improve the surface quality of the component produced.

A New Complex Grinding Method for Ceramic Materials Combined with Ultrasonic Vibration and Electrodischarge Machining

2007 ◽  
Vol 329 ◽  
pp. 439-444 ◽  
Author(s):  
Kiyoshi Suzuki ◽  
Tetsutaro Uematsu ◽  
Manabu Iwai ◽  
Shinichi Ninomiya ◽  
Sadao Sano ◽  
...  
Keyword(s):  
Removal Rate ◽  
Ceramic Materials ◽  
Grinding Wheel ◽  
Electrically Conductive ◽  
Machining Center ◽  
Grinding Method ◽  
Ultrasonic Grinding ◽  
The Us ◽  
Long Time ◽  
Stock Removal

A new complex grinding method named Ultrasonic Electrodischarging Grinding Method (US-ED-G in short) is described. In the US-ED-G, ultrasonic grinding and ED grinding are simultaneously carried out on an electrically conductive workpiece with a metal bond grinding wheel. When compared with other complex grinding methods, the US-ED-G is remarkably effective in reducing grinding force a great deal and maintaining grinding ability of a wheel for a long time in efficient grinding of extremely hard-to-grind ceramic materials like TiB2. A stock removal rate of 200mm3/min and a grinding ratio of 110 have been attained by selecting appropriate conditions in US-ED-G of TiB2. A compact and rigid ultrasonic attachment is also described, which was developed as a removable tool for carrying out US grinding and US-ED-grinding on a machining center or a grinding center.

Wear of Diamond Grinding Wheel during Low Speed Dressing by Alumina

2015 ◽  
Vol 658 ◽  
pp. 120-124
Author(s):  
Tachai Luangvaranunt ◽  
Natthawat Tangkaratanakul ◽  
Patchanok Sakultantimetha
Keyword(s):  
High Hardness ◽  
Large Mass ◽  
Diamond Wheel ◽  
Grinding Wheel ◽  
Work Piece ◽  
Wheel Wear ◽  
Diamond Grinding Wheel ◽  
Diamond Grinding ◽  
Dressing Tool ◽  
Pin On Disk

Diamond grinding wheel is used in high precision grinding process, when work piece has a very high hardness. For a specific grinding interval, the wheel must be properly dressed, in order to remove swarf, sharpen the worn diamond grits, open up new diamond protrusions, and recondition the bond material. Dressing of diamond grinding wheel by alumina dressing tool has been simulated in a pin-on-disk machine in the research. Sharpening of the wheel is indicated by the increase of its roughness value, and surface microstructure with protruding sharp diamond grits. It was found that increasing of sliding distant from 100 to 500 m will increase the roughness of the wheel. The increase of contact load from 10 to 20 N will also increase roughness of the wheel, and the severity of wheel wear, indicated by high values of friction coefficient. A proper dressing of this nickel bonded SD1200 diamond wheel is by sliding against alumina dressing tool for at least 300 m under 10 N load. Sliding velocity has minimal effect to the results. A too large sliding distant and load will cause severe damage to wheel surface, and severe wheel wear, indicated by its large mass loss.

Effect of Novel Grinding Wheels on Grinding Performance

2013 ◽  
Vol 405-408 ◽  
pp. 3302-3306
Author(s):  
Ming Yi Tsai ◽  
Shi Xing Jian ◽  
J. H. Chiang
Keyword(s):  
Surface Roughness ◽  
Pure Water ◽  
Minimum Quantity Lubrication ◽  
Grinding Wheel ◽  
Grinding Temperature ◽  
Grinding Wheels ◽  
Wheel Wear ◽  
Grinding Performance ◽  
Conventional Grinding ◽  
Removal Processes

Grinding, a technique for removing abrasive materials, is a chip-removal process that uses an individual abrasive grain as the cutting tool. Abrasive material removal processes can be very challenging owing to the high power requirements and the resulting high temperatures, especially at the workpiece-wheel interface. This paper presents a novel system that uses graphite particles impregnated in an aluminum oxide matrix to form a grinding wheel. This study specifically investigated grinding wheels with a graphite content of 0.5 wt%. The new grinding wheel was compared with conventional grinding wheels by comparing the factors of grinding performance, such as surface roughness, morphology, wheel wear ratio, grinding temperature, and grinding forces, when the wheels were used under two different coolant strategiesdry and with minimum quantity lubrication (MQL) using pure water. This study found that there is a considerable improvement in the grinding performance using graphite-impregnated grinding wheels over the performance obtained using conventional grinding wheels. The use of 0.5 wt% graphite provided better surface roughness and topography, lower grinding temperature, and decreased force; in addition, wheel consumption was lower, resulting in extended wheel life.

Effects of Impregnation of Grinding Wheel on Grinding Hardened Tool Steel

1985 ◽  
Vol 9 (1) ◽  
pp. 39-44 ◽  
Author(s):  
M.A. Younis ◽  
H. Alawi
Keyword(s):  
Structural Changes ◽  
Metal Removal ◽  
Removal Rate ◽  
Ground Surface ◽  
High Hardness ◽  
Grinding Wheel ◽  
Tool Steels ◽  
Wheel Wear ◽  
Beneficial Effects ◽  
Hardened Tool Steel

The high hardness and chemical effects of tool steels M2 and T15 cause a rapid grinding wheel wear and micro structural changes in the ground surface. The performance of sulphur-, wax-, and varnish-impregnated grinding wheels in grinding hardened tool steels M2 and T15 is investigated and compared with the performance of conventional alumina wheels. Impregnation with sulphur had in all cases beneficial effects by decreasing the grinding forces, increasing the maximum metal removal rate, improving surface integrity, and increasing considerably the grinding ratio. It also gave cost saving compared to the plain grinding wheel. The improvement was a result of the sulphur being more efficiently supplied into the chip formation process as compared to using grinding coolant only.

Development on Micro Precision Truing Method of ELID-Grinding Wheel (1st Report: Principle & Fundamental Experiments)

2005 ◽  
Vol 291-292 ◽  
pp. 207-212 ◽  
Author(s):  
Hitoshi Ohmori ◽  
Shao Hui Yin ◽  
Wei Min Lin ◽  
Yoshihiro Uehara ◽  
Shinya MORITA ◽  
...  
Keyword(s):  
High Precision ◽  
High Efficiency ◽  
High Hardness ◽  
Experimental Results ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Grinding Wheels ◽  
Elid Grinding ◽  
High Toughness ◽  
Diamond Grinding

Metal bonded diamond grinding wheels are widely used in the grinding process, especial in ELID grinding. However, truing is difficult owing to the high toughness of metal bond materials and high hardness of diamond abrasives. To realize high precision and high-efficiency truing, we propose a new micro-truing method consisting of electro-discharge truing and electrolysis-assisted mechanical truing in this paper. The process principle and fundamental experimental results are introduced, and the truing performance is discussed. Research results show that the proposed new method is effective for truing metal bonded diamond grinding wheels.

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