ANALYSIS OF HYDRODYNAMIC FORCES IN GRINDING Grinding of structural ceramics using fast wheel speeds and a copious fluid supply can cause significant hydrodynamic forces. The present investigation was undertaken to provide a fundamental description of the hydrodynamic behavior. Hydrodynamic forces were measured for various pre-set gap thicknesses between the wheel and the workpiece. The measured forces were analyzed by applying hydrodynamic theory to the converging inlet between the wheel and the workpiece. It was found that the inherent roughness of the grinding wheel surface could be taken into account by adding a correction factor to the gap thickness equal to the measured peak-to-valley roughness of the wheel surface. > More Info

A NOVEL METHOD FOR IN-PROCESS DETECTION OF GRINDING WHEELS SURFACE TOPOGRAGHY The cutting edges of a grinding wheel are geometrically undefined in locatoins and shapes. As a result, generalisation or estimations of the grinding wheel surface condition are difficult to make with any degree of accuracy. Therefore, It is necessary to develop techniques for examining details of the grinding wheel topography in order to ascertain quantitative measurements of cutting edges. This paper describes the sensitivity, accuracy, working range and other statistical parameters for the highly accurate novel sensor that detects in-process changes of the ginding wheel topography. The sensor based on measuring static pressure variations in an impinging jet of air on a surface by a miniature high frequency transducer. Experimental work was carried out to ensure the benefits of this sensor. The sensor was calibeated using standards surface roughness specimens. The sensor can be used for measuring accurate distances, shafts or cams run out, form errors, as well as surface roughness and surface structure. > More Info

GRINDING FLUID PERFORMANCE & CHARACTERIZATION OF WHEEL WEAR A grinding fluid"s effectiveness in lubricating the work zone, reducing frictional forces, cooling the wheel and workpiece, preventing thermal damage, and maintaining a clean wheel and workpiece surface are critical for optimizing metal removal rates, wheel life and ground part quality. > More Info

Ultra-high Speed Grinding using a CBN Wheel for a Mirror-like Surface Finish By M. Ota, T. Nakayama, K. Takashima and H. Watanabe There are strong demands for a machining process capable of reducing the surface roughness of sliding parts, such as auto parts and other components, with high efficiency. In this work, we attempted to grind hardened steel to a mirror-like surface finish with high efficiency using an ultra-high speed grinding process. In the present study, we examined the effects of the work speed and the grinding wheel grain size in an effort to optimize the grinding conditions for accomplishing mirror-like surface grinding with high efficiency. > More Info

Magnetic Filtration as an Alternative to Media Based Systems in Industrial Coolant or Oil Systems Magnetic Filtration offers a number of advantages over traditional media based filtration, in terms of Economics, Ecological impact and Efficiency, three areas which probably all manufacturing companies will have targeted for improvement. > More Info

EFFECTS OF GRINDING FLUIDS IN HIGH EFFICIENCY DEEP GRINDING Sufficient supply of grinding fluids into the grinding zone is essential in high efficiency deep grinding (HEDG) to control the ground workpiece surface integrity. Good lubrication provided by grinding fluids serves to keep the specific grinding energy at a low level and reduce the wheel wear. > More Info

GRINDING FLUID EFFECTIVENESS IN CDCF GRINDING Creep feed grinding is a high-productivity abrasive removal process that is often limited by thermal damage and high wheel wear. A review of current industrial practices in the area of coolant supply optimization in grinding shows that very little knowledge of pressure, flowrate and method of appliocation exists in industry. This paper presents an experimental procedure to evaluate the lower limit of coolant flow rate for a given grinding system consisting of a common wheel type, material type, and coolant type. > More Info

Fabrication and Wear of Nitrogen-doped Diamond Microtools By Mark J. Jackson and Waqar Ahmed Chemical vapour deposited diamond films have many industrial applications but are assuming increasing importance in the area of microfabrication, most notably in the development of diamond-coated microtools. For these applications the control of structure and morphology is of critical importance. The crystallite size, orientation, surface roughness and the degree of sp3 character have a profound effect on the machining properties of the films deposited. In this paper, experimental results are presented on the effects of nitrogen doping on the surface morphology, crystallite size, and wear of microtools. It is concluded that the magnitude of tensile stresses induced in the diamond grain by grinding forces at the rake face is the best indicator of tool wear during the grinding process. > More Info

Investigation into Integration Manufacturing Technology of Grinding and Precision Finishing By Li Changhe, Hou Yali, and Cai Guangqi The Integration Manufacturing Technology is a kind of compound precision finishing process that combined grinding with abrasive jet finishing, in which inject slurry of abrasive and liquid solvent to grinding zone between grinding wheel and work surface under no radial feed condition when workpiece grinding were accomplished. The abrasive particles are driven and energized by the rotating grinding wheel and liquid hydrodynamic pressure and increased slurry speed between grinding wheel and work surface to achieve micro removal machining. In the paper, the surface microscopic topography by the Integration Manufacturing Technology were evaluated and analyzed. Experiments were performed with plane grinder M7120 and workpiece material 40Cr. The machined surface morphology was studied using SEM and the microscope and microcosmic geometry parameters were measured with TALYSURF5 instrument. The experimental results show that that longitudinal geometry parameter values of finishing machining surface were diminished comparing with ground surface,and the mean ripple distance was decreased and, ripple and peak density were increased. Furthermore, The finished surface has little comparability compared to grinding machining surface.The isotropy surface and uniformity veins at parallel and perpendicular machining direction were attained by the Integration Manufacturing Technology. > More Info

Approaches to Improve Grinding Fluid Application Rising demands on workpiece quality and increasing cutting speeds changed the importance of grinding fluids in production. Today, the successful use of grinding fluid requires substantial know-how of the end-user. In order to design an optimized application of the grinding fluid, product, process and periphery-dependant boundry conditions have to be taken to account. > More Info

Model Based Simulation of Grinding Processes By Stephen Malkin and Changsheng Guo Grinding is widely used for final machining of components requiring smooth surfaces and precise tolerances. Extensive research conducted during the past 40 years has provided a relatively clear understanding of the many diverse aspects of the grinding process. The objective of this paper is to show how our understanding of the grinding process can be utilized to predict grinding behavior and achieve optimal operating conditions. > More Info

MICROGRINDING HYPEREUTECTOID STEELS By Mark J. Jackson Microgrinding of hypereutectoid steels is a process that is comparable to that of superfinishing using a fine grained honing tool. The process is especially suitable for finish machining components such as bearing races. The paper describes themorphological changes made to conventional grinding wheels when dressed with a highly focused laser beam. The microstructure is influenced by the cooling rate associated with laser processing conditions, and the resulting microstructure is significantly affected by the way grains are orientated in the re-solidified layer of the grinding wheel. Cooling rates and orientated imaging confirm that a preferred orientation of grains along the (110) planes is the reason for the formation of cutting points on the newly formed grinding surface. The existence of competitive growth of grains also explains why certain area of the modified abrasive material removes material in an uneven manner. The experimental machining results also show that the abrasive material grinds away the workpiece material in addition to removing the newly created abrasive surface, which tends to suggest that continuous dressing of the abrasive material is normally required. > More Info

Grinding consultants – What they do and are they worth the money by Jeffrey A. Badger, Ph.D. In the past 20 years, manufacturing plants have become leaner and leaner, in part to compete with low-wage countries. As a result, manufacturers employ fewer – if any – metallurgists and engineers devoted to troubleshooting and process improvements. Shop-floor supervisors, engineers and machine operators have time for just one thing: production. Consequently, in-house technical expertise has slowly evaporated, resulting in lost production, a lack of innovative improvements and an inability to quickly address technical problems. > More Info

United Abrasives, Inc. / SAIT has four new products United Abrasives, Inc. / SAIT has four new products that really take the abrasives industry to a whole new level in 2007. > More Info

Castings Company Increases Productivity with EZEFIT™ Wheels A current QS-9000 qualified Indiana producer of grey iron castings, in business since 1937, is benefiting from an EZEFITTM wheel upgrade to improve the cleaning of their high production castings such as water pumps, compressor housings, manifolds, gas valves, pulleys, gears and housings. > More Info

New Superabrasive Gashing Product Webster, MA- Winterthur Corporation, a subsidiary of Winterthur Technology Group, offers a new product for grinding high speed steel and carbide cutting tools. > More Info

Guardair Introduces Lazer™ 600 Series Safety Air Guns Breakthrough Design for Comfort and Convenience CHICOPEE, MA – Guardair Corporation has introduced their new LazerTM 600 Series of Safety Air Guns, which feature a unique comfort-grip design. > More Info