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Ductile regime grinding, proposed by Bifano, is an important method for achieving high quality surfaces of hard brittle materials . Bifano also gave a theoretical description of the ductile grinding condition of different brittle materials, pointing out that ductileregime grinding could be achieved by a .
Ductile regime grinding of ferrite with variation of grain size by a piezoelectricdriven micropositioning grinding table JD Kim and SR Nam Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Taejon, Korea Abstract: A mirrorlike grinding of brittle materials is required in many precision ...
Dec 16, 2014· Ductile regime grinding is an effective machining process that has been used for brittle materials for several years now. In ductile regime grinding, material is removed through plastic deformation, which reduces the risk of fractures and compromised materials. Regime grinding also eliminates or minimizes the need for polishing and lapping ...
For the ductile mode grinding of hard and brittle materials, the critical machining depth ranges from 50 nm to 1 m [20]. To perform ductile mode machining of brittle materials, machine tools with highaccuracy servomechanisms (resolution –10 nm), high loop stiffness, and full flood
In ultraprecision grinding of brittle materials, the transition from ductileregime grinding to brittleregime grinding that results from an increasing grinding grain depth of cut is accompanied by a reduction in the specific grinding energy. Furthermore, as the grain depth of cut is increased beyond the transition point into purely
grinding ductile or brittle materials. In a brittle material, the "chips" are just smaller. The removal mechanism for a brittle material is achieved through microfracture and the subsequent removal of the chips by the next passing grain (see Figure 1).
This process is known as ductileregime grinding. When brittle materials are ground through a process of plastic deformation, surface finishes similar to those achieved in polishing or lapping are produced. Unlike polishing or lapping, however, grinding is a deterministic process, permitting finely controlled contour accuracy and complex shapes.
With the brittle cracks remains, the finished surface quality of ultrighspeed machining is worse than that of highspeed machining. The results show that the material property undergoes ductiletobrittle transition so the brittle regime machining of ductile materials .
DuctileRegime Turning of Brittle Materials by Single Point Diamond Ichiro Ogura, Yuichi Okazaki ... Blake and Scattergood investigated the critical depth of cut for single crystals of germanium ... T. Bifano, T. Dow, and R. Scattergood: Ductile Regime Grinding: A New Technology for Machining Brittle Materials. ASME, J. Eng. Ind., 113, 5 (1991 ...
The applied hydrostatic pressure enhanced the critical cross sectional area and reduced the cracks and chippings of all the tested materials. Effects of hydrostatic pressure on the machining characteristics of the crystalline and glassy materials are discussed in detail.
Brittle materials have been widely employed for industrial applications due to their excellent mechanical, optical, physical and chemical properties. But obtaining smooth and damagefree surface on brittle materials by traditional machining methods like grinding, lapping and polishing is very costly and extremely time consuming.
Aug 07, 2013· The normal stress distribution profile associated with grinding a ductile material does not apply to grinding a brittle material like an advanced ceramic. Any induced tensile stress, which is usually caused by restricted thermal expansion at high temperatures, has already resulted in microcracking beneath the surface, as in a brittle material ...
Supplement Vo!. 12, 2004 Precision Grinding of Hard and Brittle Materials Fig. 2: High speed jig grinding of silicon and glass Two grinding wheel bond types, metal and resinoid, each with three different grit sizes, 1030 mm, 4060 mm and 5070 mm were used in generating aspheric surfaces using the grinding zone method.
only when chip removal is done at the atomic level. Recent developments of ductile mode machining of hard and brittle materials show that plastically deformed chip removal minimizes the subsurface damage of the workpiece. When chip deformation takes place in the ductile regime, a .
[3] in his paper on ductile or partial ductile mode machining of brittle materials discussed the machining mode for silicon, glass, and some advanced ceramics. Scanned electron ...
This paper proposes machining under high hydrostatic pressure as a new damagefree machining method for hardbrittle materials. Experiments for this study utilized a specially designed scratching test device, and the pinondisc scratching tests were conducted with three (3) hardbrittle materials (, silicon, glass, and quartz) under pressure of 400 MPa and zero MPa.
PREDICTIVE MODELING FOR DUCTILE MACHINING OF BRITTLE MATERIALS A Dissertation Presented to The Academic Faculty By Sivaramakrishnan Venkatachalam In Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy in the George W. Woodruff School of Mechanical Engineering Georgia Institute of Technology December, 2007
The ductile grinding of optical materials is a rapidly evolving process. Ductile regime grinding is the technology of grinding brittle materials at material removal rates and depth of cuts that allow for predominantly ductile removal of material as opposed to brittle fracture of the material. It has been
Precision machining of germanium and silicon was studied using single‐point diamond turning. Special attention was directed to the so‐called ductile regime wherein optical quality surface finishes can be machined directly on brittle materials.
Abstract Ductileregime grinding is a new technology made possible by the use of realtime control and precision engineering in the grinding process. By ensuring that the abrasive grinding forces do not exceed a threshold value, it is possible to grind materials that are normally considered "brittle" in such a way that the material removal ...
and on ductileregime machining of brittle materials. When a material was ma chined in such a fine scale that satisfied ductileregime conditions, then the chip was removed in a ductile manner despite the brittle nature of the material. A model for the critical depth associated with ductileregime in micromachining was proposed (6):
Ductile regime grinding, a new grinding technology for brittle materials, is considered as a solution of this difficulttocut materials grinding. It is known that a fracture mechanism of brittle materials is transient to plastic deformation in the region of extremely small depth of grinding or removal rates.
This process is known as ductileregime grinding. When brittle materials are ground through a process of plastic deformation, surface finishes similar to those achieved in polishing or lapping are produced. Unlike polishing or lapping, however, grinding is a deterministic process, permitting finely controlled contour accuracy and complex shapes.
Jan 01, 1997· Under appropriate conditions, brittle materials may be ground to produce surfaces with no observable fracture damage. This chapter reviews the techniques for... DuctileRegime Grinding of Brittle Materials | NIST
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