The micromechanisms of ductile removal in the grinding of brittle materials have been topics of debate. Extensive experimental (indention, scratch, grinding) studies and numerical simulations in the past two decades have demonstrated that an ordinarily …
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The basic science of attendant deformation and removal modes in contact events is here analyzed and discussed in the context of brittle and ductile machining and severe and mild wear. Essentials of brittle–ductile transitions in micro- and nano-indentation fields are outlined, with distinctions between blunt and sharp contacts and …
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Micro-grinding is a tool based mechanical micromachining process which is mostly applied to create and finish 3D micro-features on hard and brittle materials such …
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Several attempts to understand the ductile behaviour of brittle materials have been made ... 498-509 7 Bifano, T. G. Ductile-Regime Grinding of Brittle Materials, ... A critical energy model for brittle–ductile transition in grinding considering wheel speed and chip thickness effects ... Ductile regime grinding of brittle materials.
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The critical grinding depth of ductile-brittle transition is an important processing parameter to guarantee brittle materials machining in ductile mode. …
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Abstract. The material removal process takes place due to phenomena such as plastic deformation and brittle fracture. A long continuous chip is formed when the plastic deformation dominates, whereas a fracture-induced discontinuous chip is formed when the brittle fracture dominates. The means of material removal changes at a …
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Testing the Ductile-Regime Grinding Hypothesis Earlier in this paper, a basic hypothesis was postulated for ductile-regime grinding: all materials, regardless of their hardness or brittleness, will undergo a transition from brittle machining regime to a ductile machining regime if the grinding infeed rate is made small enough (Bifano et aI., 1987).
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brittle-to-ductile transition in terms of the material properties of the workpiece and the rate of material removal. In this paper, three aspects of the research are described: 9 …
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Conventional grinding of BK7 glass will normally result in brittle fracture at the surface, generating severe sub-surface damage and poor surface finish. The precision grinding of BK7 glass in parallel grinding modes has been investigated. Grinding process, maximum chip thickness, ductile/brittle regime, surface roughness and sub …
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Brittle materials have been widely employed for industrial applications due to their excellent mechanical, optical, physical and chemical properties. But obtaining smooth and damage-free surface on brittle materials by traditional machining methods like grinding, lapping and polishing is very costly and extremely time consuming. Ductile …
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This process is known as ductile-regime grinding. When brittle materials are ground through a process of plastic deformation, surface finishes similar to those …
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Ductile regime grinding, a new grinding technology for brittle materials, is considered as a solution of this difficult-to-cut 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.
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The ductile–brittle transition and ductile-regime removal mechanisms of ZnS crystal, a typical soft-brittle infrared optical material, have remained unclear at the micro- and nanoscale. In this context, this study modeled the energies consumed in two machining modes, namely ductile deformation and brittle fracture, during the …
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The process parameters (depth of cut, feed etc.) to achieve transition between ductile and brittle modes of material removal have been reported (Blake and Scattergood, 1990, Blackley and Scattergood, 1991, Patten et al., 2005) to be in the micrometer and nanometer regime. Hence ductile-regime machining is categorized as a precision or …
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This study analyzes the damage associated with current brittle-regime grinding and presents a potential remedy in the application of a safer yet still efficient grinding regime known as "ductile-regime grinding." Disc-shaped specimens of a lithium disilicate glass-ceramic material (IPS e.max CAD) were obtained by cutting and …
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To suppress cracks during the grinding of brittle materials, ductile‐regime grinding [1], which stems from a mechanical model based on ceramic indentation [2], is …
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Ductile-Regime Grinding Of Brittle Materials: Experimental ... Ductile-regime grinding is a new technology made possible by the use of real-time 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 ...
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Fig 1 Photograph of the ductile and brittle fracture on the machined shoulder. 145 x PRECISION ENGINEERING 1991 Butterworth- Heinemann 95 Blackley and Scattergood- Ductile-regime machining model for diamond turning of brittle materials Blake',' focused on measuring ductility through the movement of the ductile-to-brittle …
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Ensuring ductile removal in a grinding process is crucial for achieving the desired finish on a hard and brittle single crystal. This study provides new insights into the material removal processes in Si and GaAs single crystals, exploring their deformation behaviour using Berkovich and Conical tips to replicate contact from a fixed abrasive grit.
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Empirical evidence has shown that grinding wheel characteristics significantly affect performance in the grinding of brittle materials. In this research a grit depth of cut model was developed based on a kinematic simulation of the grinding process. The model describes the relationships between grinding wheel parameters …
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Ductile-regime grinding is a new technology made possible by the use of real-time 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 takes place through plastic …
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ductile regime grinding brittle materials sayulamx. In grinding of brittle materials,it is easy to produce quality problem such as surface/subsurface damage during . Get Price; precision grinding of hard and brittle materials. precision grinding of hard and brittle materials Ductile grinding is an ideal method for producing a mirror finished ...
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Ductile regime machining is an alternative method for polishing of brittle materials to obtain a high quality surface finish by a ductile or plastic material removal process. Hence, there is a growing interest to study ductile regime machining over several decades. This paper reviews current state of research and development in ductile …
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Material removal mechanisms of micro-grinding of brittle materials are grouped into ductile deformation and brittle fracture [14]. The brittle fracture is likened to indentation on a brittle material by a harder indenter which involves lateral and radial/median cracks (Fig. 7) [59]. The coalescence of precursory subsurface defects ...
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The brittle-ductile transition in the micro drill-grinding of hard brittle materials was investigated. A ductile regime propelling technology of a resin coating was proposed and successfully ...
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During ordinary cutting, if UCT is smaller than the critical value (t c), crack-free surface on brittle materials can be achieved, which is normally termed as ductile machining [14].For UEVC of brittle materials, as UCT gradually increases from zero to a maximum value (UCT m) as shown in Fig. 1, if UCT m is maintained no larger than t c …
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All the above researches indicate that the ductile regime removal can be achieved in the brittle materials' grinding as in the machining of the metallic materials. For the grinding of Si 3 N 4, the material removal in the machining zone is mostly a mixed-mode of ductile and brittle [ 11, 12 ].
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In his research, it pointed out that different materials have variable brittle-ductile transition grinding depth which is clarified in the following formula 2.3: 2 (/ )( / ) IC hEHKH Ε (2.3) 0.15 Ε . Using 2.3, brittle and hard materials ductile and brittle removal phase is divided into two parts.
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A machining model has been developed to ensure ductile regime machining of the brittle material, in which the material is removed by both plastic deformation and brittle fracture, but the cracks produced are prevented from being extended into the finished surface. ... [30] Bifano T G, Dow T A and Scattergood R O …
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Ductile-regime grinding is a new technology made possible by the use of real-time control and precision engineering in the grinding process. By ensuring that the abrasive …
WhatsApp: +86 18221755073