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Subsurface damage (SSD) and grinding damage-induced stress (GDIS) are a focus of attention in the study of grinding mechanisms. Our previous study proposed a load identification method and analyzed the GDIS in a silicon wafer ground (Zhou et al., 2016, “A Load Identification Method for the GDIS Distribution in Silicon Wafers,” Int. J. Mach. Tools Manuf., 107, pp. 1–7.). In this paper, a more concise method for GDIS analysis is proposed. The new method is based on the curvature analysis of the chip deformation, and a deterministic solution of residual stress can be derived out. Relying on the new method, this study investigates the GDIS distribution feature in the silicon wafer ground by a #600 diamond wheel (average grit size 24 μm). The analysis results show that the two principal stresses in the damage layer are closer to each other than that ground by the #3000 diamond wheel (average grit size 4 μm), which indicates that the GDIS distribution feature in a ground silicon wafer is related to the depth of damage layer. Moreover, the GDIS distribution presents a correlation with crystalline orientation. To clarify these results, SSD is observed by transmission electron microscopy (TEM). It is found that the type of defects under the surface is more diversified and irregular than that observed in the silicon surface ground by the #3000 diamond wheel. Additionally, it is found that most cracks initiate and propagate along the slip plane due to the high shear stress and high dislocation density instead of the tensile stress which is recognized as the dominant factor of crack generation in a brittle materials grinding process.

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X-ray fluorescence (XRF) in combination with partial least-squares (PLS) regression was employed to analyze the ore slurry grade. Using the Monte Carlo simulation code PENELOPE, X-ray fluorescence spectra of ore samples were obtained. Good accuracy was achieved when this method was used to analyze elements with concentrations of several percent or above. It was demonstrated that the more the number of X-ray fluorescence spectra used to calibrate, the better the obtained accuracy. In this method detector resolution was found to have little or no effect on the results of quantitative analysis. The effect of the concentration of water was investigated as well, and it was found to have little influence on the results.

Micromachining of brittle materials like monocrystalline silicon to obtain deterministic surface topography is a 21 st Century challenge. As the scale of machining has shrunk down to sub-micrometre dimensions, the undulations in the machined topography start to overlap with the extent of elastic recovery (spring back) of the workpiece, posing challenges in the accurate estimation of the material's elastic recovery effect. The quantification of elastic recovery is rather complex in the grinding operation due to (i) randomness in the engagement of various grit sizes with the workpiece as well as (ii) the high strain rate employed during grinding as opposed to single grit scratch tests employed in the past at low strain rates. Here in this work, a method employing inclination of workpiece surface was proposed to quantify elastic recovery of silicon in ultra-fine rotational grinding. The method uniquely enables experimental extraction of the elastic recovery and tip radius of the grits actively engaged with the workpiece at the end of the ultra-fine grinding operation. The proposed experimental method paves the way to enable