A critical energy model for brittle–ductile transition in grinding considering wheel speed and chip thickness effects

Abstract

The ability to predict the critical depth for ductile-mode grinding of brittle materials is important to grinding process optimization and quality control. The traditional models for predicting the critical depth are mainly concerned with the material properties without considering the operation parameters. This article presents a new critical energy model for brittle–ductile transition by considering the strain rate effect brought by the grinding wheel speed and chip thickness. The experiments will be conducted through a high-speed diamond grinder on reaction-sintered silicon carbide materials under different grinding speed and chip thickness. Through detailed analysis of the strain rate effect on the dynamic fracture toughness, a new fracture toughness model will be established based on the Johnson–Holmquist material model (JH-2) and calibrated through experiments based on the indentation fracture mechanics. Then, the new critical model for brittle–ductile transition will be established by introducing the dynamic facture toughness model considering the wheel speed and chip thickness. According to scanning electron microscope observations, the results show that ductile-mode grinding can be obtained through a combination of higher grinding speed and smaller chip thickness. Moreover, the critical value for ductile grinding of brittle materials can be improved through the elevation of the grinding speed or reduction in the chip thickness.

Removal mechanism of 4H- and 6H-SiC substrates (0001 and 0001¯) in mechanical planarization machining

“…However, SiC is difficult to machine because of its extreme hardness and chemical inertness, which limit its application considerably. 12–15…”

A new model and metaheuristic approach for the energy-based resource-constrained scheduling problem

“…These strategies can be classified into two levels: the machine tool level and manufacturing system level [11]. The first level refers to improving the process taking into account the machine design that performs the operation from a technological point of view [12,13,14]. For a comprehensive review about this first level, we refer the reader to [15].…”

“…11 The first level refers to improving the process taking into account the machine design that performs the operation from a technological point of view. [12][13][14] For a comprehensive review about this first level, we refer the reader to Moradnazhad and Unver. 15 The second level emphasizes energy optimization through the management and allocation of the activities and resources with the objective of minimizing energy requirements.…”

“…30 Thus, expression (14) is proposed, where t i (c i ) is the proportion of processing time compared with the standard duration of activity i, and c i is the proportion of energy consumption compared with the standard consumption of activity i. Expression (14) has a decreasing trend in a way similar to the energetic behavior in machine tools. This function represents an approximation of the proposed efficiency model in the previous section.…”

Comparison of Machining Temperature in High Speed Grinding of Metallic Materials and Brittle Materials

“…However, grinding is also a complex machining process with dynamic active number, random grit topology and cutting angle. The interactive abrasive grits have typical negative rake angle [3], which will cause a high degree of material deformation and thus produce voluminous grinding heat and unpleasant residual stress [4]. Moreover, the grinding induced temperature is obviously different when machining different materials.…”