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 …
Surface formation mechanism of hard brittle material in micro-grinding is analyzed. The mathematical model of undeformed chip thickness hm in slot micro-grinding is built. A model to describe complex critical condition of ductile-regime in micro-grinding of hard brittle material is proposed considering size effect factor Md and micro-grinding tool …
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 …
Silicon carbide (SiC) ceramics play a key role in various engineering applications due to their desirable properties, however, they are typical hard-brittle materials and famous for their poor machinability. Ultrasonic-assisted grinding, a processing method hybridizing the conventional grinding and ultrasonic vibration (UV) …
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).
The brittle–ductile transition of the brittle materials correlates to dynamic fracture toughness, micro-hardness of the material, the coolant and so on. Eq. (8) considers the impulse load in grinding process, as well as the coolant's influence on the hardness and fracture toughness, which will accord with actual machining process better …
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 …
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.
Brittle-Ductile Transition Phenomena in Microindentation and Micromachining Shoichi Shimada Toyos hiro Hitos hi (2), Naoya lkawa (I), Dept. of Precision Engineering, Osaka University Inamura, Nobuhiro Takezawa, Nagoya Institute of Technology Ohmori, RlKEN Institute of Physical and Chemical Research Toshio Sata …
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 …
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 …
DOI: 10.1016/0141-6359(91)90500-I Corpus ID: 138563121; Ductile-regime machining model for diamond turning of brittle materials @article{Blackley1991DuctileregimeMM, title={Ductile-regime machining model for diamond turning of brittle materials}, author={W. S. Blackley and Ronald O. Scattergood}, journal={Precision Engineering …
Grinding of brittle materials is characterized by a complex removal mechanism of both ductile and brittle removal. Therefore, the traditional force models, which are mainly targeted to metallic materials, cannot be fully applied to the force prediction of brittle materials. ... Ductile-regime grinding: a new technology for …
BRITTLE MATERIALS GRINDING IN DUCTILE-REGIME (GRINDING) Submitted to: Asst. Prof. M. P. Gururajan Dept. of Applied Mechanics, I. I. T Delhi Submitted by: Raja Vardhan Movva 2008 AMD 3103 . Introduction: Manufacturing of a component must provide its basic size and shape with desired surface finish and tolerances. Grinding is one most widely …
Ductile grinding of brittle materials is essential for high precision applications and to maintain the strength and lifetime of the parts. The critical chip thickness of a brittle material defines a threshold for the lateral cracks' initiation in the workpiece due to the grains' penetration. ... Ductile-Regime Grinding of Brittle Materials ...
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 ].
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 ...
The prediction of the critical depth for ductile grinding of brittle materials is of great importance for grinding process optimization and quality control. ... Predictive cutting force model for ductile-regime machining of brittle materials. Int J Adv Manuf Technol, 98 (1–4) (2018), pp. 781-790, 10.1007/s00170-018-2273-6. View in Scopus ...
Subsequently, the ductile regime grinding of the microstructured surface was examined for WC cermet and BK7 optical glass. The ground surfaces mainly under the ductile regime material removal were successfully achieved, especially in the case of WC ceramic. ... The precision grinding of hard and brittle materials by a conditioned …
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 Development of a grinding apparatus capable of ductile-regime grinding on brittle materials. The relevant design features include: — Machine configuration
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.
Ductile regime turning is a new technology for obtaining a crack-free surface on brittle material. However, the fundamental obstacle for industrial application of this technology is diamond tool wear. This problem is difficult to solve for existing methods of turning with round-nosed tools due to limitation on tool feed.
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 …
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 …
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 …
An experimental study has been made of the friction and strength properties of crystalline materials such as rock-salt, lead sulphide and ice. From frictional measurements on …
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 …
Ductile-regime grinding technology, as a precise grinding method for hard and brittle materials, aims to achieve material removal through plastic deformation[19]. ... removal mode of brittle materials is a challenging task. Bifano et al.[19] developed a critical depth-of-cut model for grinding hard and brittle materials, incorporating …
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 …
This process is known as ductile-regime grinding. When brittle materials are ground through a process of plastic deformation, surface finishes similar to those achieved in polishing or lapping are produced. ... Furthermore, an analytical and experimental investigation of the infeed rates necessary for ductile-regime grinding of brittle ...
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