Prediction of grinding force for brittle materials considering co-existing of ductility and brittleness

Abstract

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. This paper will propose a new grinding force model for brittle materials considering co-existing of ductile removal force and brittle removal force. The ductile removal force is mainly composed of rubbing force, ploughing force, and chipping force. However, the brittle removal force is more related to rubbing force and fracture chipping force. The proportional coefficient of ductile removal and crack size will be modeled through a series of experiments under different wheel speed and undeformed chip thickness. The working status for a single grit was separated based on the Hertz Theory and chip thickness modeling of Rayleigh probability density function. Grinding experiments have been undertaken by using a high speed diamond grinder on Silicon Carbide, and the results was compared to the force model predictions for validation. The predictive force model shows a reasonable agreement quantitatively with the experimental force data.

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

“…The semi-included angle of the active grit θ is 60°. 30 The value of N d , in equation (2), can be derived as follows 31…”

Ductile grinding of Silicon carbide in high speed grinding

“…Two parts of the workpiece are polished by a 0.5µm diamond paste to examine subsurface damage and then bonded together using a cyanoacrylate-based adhesive. Clamping pressure was applied during bonding to ensure that a thin adhesive layer joint was achieved, which would minimize edge chipping during grinding (Wu et al, 2016). The grinding direction was perpendicular to the bonded interface.…”

Removal mechanism of machinable ceramics and theoretical model of cutting force in turning operation

“…Liu et al (2012) studied the cutting mechanism of rotary ultrasonic grinding of brittle materials, and considered that the main removal mechanism of brittle materials was brittle fracture, and established the cutting force model of rotary ultrasonic grinding of brittle materials. Wu et al (2016) considered that both ductility removal and brittleness removal existed in the grinding process of brittle materials, and proposed the grind-ing force model of brittle materials under the combined action of ductility removal force and brittleness removal force; Xie et al (2008Xie et al ( , 2011 analyzed two removal methods of plastic deformation and brittle fracture of engineering ceramics, studied the relationship between cutting deformation force and material properties and grinding parameters, and established the grinding force model of high-speed deep grinding of engineering ceramics; Lin et al (2012) studied the stress changes of elastic deformation, plastic deformation and crack initiation in the process of material removal, and established a single abrasive grinding force model based on stress concentration theory; Li et al (2018) established the micro-grinding force model of reaction-bonded silicon carbide (RB-SiC) ceramics by considering the brittle fracture of materials, grinding conditions and random distribution of abrasive particles in grinding wheels; Zhang et al (2017) studied the contact behavior of a single abrasive particle with work piece material at different grinding depths, analyzed the material removal mechanism and plastic accumulation mechanism, determined the critical transition between plow and cutting, and established an improved theoretical model of Published by Copernicus Publications. grinding force.…”