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The sintered shale brick and light-weight sintered shale brick are both of brittle wall materials. The mechanical and other properties will be affected greatly by tensile force producing the lime burst. Through analysis of physical and chemical properties of raw materials, the reason of lime burst, and the comparative experiments of lime burst, studied on similarities and differences between the two wall materials, providing important technical parameters for the follow-up research, production and construction in the feature.

Based on the theory of energy transfer, this study analyzes the fracture mechanism of machinable ceramics, and establishes the machinable ceramic tool-workpiece-chip coupling cutting force model. Research on the brittleness removal of hard and brittle materials by indentation test. The pre-existing defects on the surface of the workpiece are subjected to tensile stress. With continuous loading on a certain point on the surface of the workpiece, the cracks begin to sprout and expand; when the critical load is loaded, the cracks become unstable; with the load continues, the conical cracks expand in an unstable state. The Hertz crack system is obtained at the end of the indentation. The crack system model is established based on indentation fracture mechanics. According to Griffith energy balance theory, different types of energy models of the crack system are established. The theoretical model of cutting force is established according to the principle of energy conservation, the tool input is equal to the energy change between crack systems. The results of turning experiments show that the main cutting force increases with the increase of the radius of the tool nose, and decreases with the increase of the tool rake angle. The calculated values of the theoretical model of cutting force in turning of hard and brittle materials are basically consistent with the experimental values.