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This work use the SPH method to study the relationship between grinding depth and grinding force of K9 glass in ultra-precision grinding, and the effect of grain shape on material removal. The relationship between the force and the depth in the stable scratching stage is FR = 0.55078ap1.15356, which provides a basis for controlling the grinding depth by force. The material removal modes at different grinding depths were obtained, that is, plastic removal occurs below 0.2 μm, brittle transition occurs between 0.2 and 0.4 μm, and brittle removal occurs at more than 0.5 μm. It is found that the cutting resultant force of sharp grains is smaller and the normal force is smaller than the tangential force. By analyzing the plastic deformation depth and residual stress depth, it is found that the material removal mode with small deformation and little removal has the lowest cutting force fluctuation and the highest grinding quality. It provides a reference for the choosing of grain shape in rough grinding and ultra-precision grinding. The correctness and reliability of the simulation results were verified by the comparison of the simulation findings with the results obtained from varied-depth scratching experiments and the multi-shape indenter scratch experiments. [ABSTRACT FROM AUTHOR]

K9 optical glass has superb material properties used for various industrial applications. However, the high hardness and low fracture toughness greatly fluctuate the cutting force generated during the grinding process, which are the main factors affecting machining accuracy and surface integrity. With a view to further understand the grinding mechanism of K9 glass and improve the machining quality, a new arithmetical force model and parameter optimization for grinding the K9 glass are introduced in this study. Originally, the grinding force components and the grinding path were analyzed according to the critical depth of plowing, rubbing, and brittle tear. Thereafter, the arithmetical model of grinding force was established based on the geometrical model of a single abrasive grain, taking into account the random distribution of grinding grains, and this fact was considered when establishing the number of active grains participating in cutting Nd-Tot. It should be noted that the tool diameter changed with machining, therefore this change was taking into account when building the arithmetical force model during processing as well as the variable value of the maximum chip thickness amax accordingly. Besides, the force analysis recommends how to control the processing parameters to achieve high surface and subsurface quality. Finally, the force model was evaluated by comparing theoretical results with experimental ones. The experimental values of surface grinding forces are in good conformity with the predicted results with changes in the grinding parameters, which proves that the mathematical model is reliable.

K9 optical glass has superb material properties used for various industrial applications. However, the high hardness and low fracture toughness greatly fluctuate the cutting force generated during the grinding process, which are the main factors affecting machining accuracy and surface integrity. With a view to further understand the grinding mechanism of K9 glass and improve the machining quality, a new arithmetical force model and parameter optimization for grinding the K9 glass are introduced in this study. Originally, the grinding force components and the grinding path were analyzed according to the critical depth of plowing, rubbing, and brittle tear. Thereafter, the arithmetical model of grinding force was established based on the geometrical model of a single abrasive grain, taking into account the random distribution of grinding grains, and this fact was considered when establishing the number of active grains participating in cutting Nd-Tot. It should be noted that the tool diameter changed with machining, therefore this change was taking into account when building the arithmetical force model during processing as well as the variable value of the maximum chip thickness amax accordingly. Besides, the force analysis recommends how to control the processing parameters to achieve high surface and subsurface quality. Finally, the force model was evaluated by comparing theoretical results with experimental ones. The experimental values of surface grinding forces are in good conformity with the predicted results with changes in the grinding parameters, which proves that the mathematical model is reliable. [ABSTRACT FROM AUTHOR]