Influence of production factors on the strength of ceramic materials

Abstract

1. It is experimentally shown that the 95% aluminum oxide-base ceramic has the highest compressive strength among the materials considered, σc=3100 MPa, which is almost 15 and 30% more than the similar characteristics for cast STL-10 pyroceram and 13v technical glass, respectively. 2. The difference between the axial compressive, tensile, and pure bend strengths of specimens cut from sections and parts of chemically resistant porcelain and ceramic VIII produced by forming of a plastic mixture and slip casting in gypsum molds is from 25 to 40%. At the same time the difference between the compressive strength of specimens of ceramic VIII oriented at a right angle in cutting from the nozzle type part produced by slip casting in a gypsum mold reached 60%. 3. The axial compressive strength of the investigated ceramics increases with an increase in aluminum oxide content and decreases with an increase in silicon dioxide content. The bend strength of the ceramics may be increased by 15–80% by selection of the optimum machining conditions and firing temperature of the sections and by decreasing the porosity of the material. 4. The spread in experimental values of the strength of aluminum oxide-base ceramic materials under bending conditions, conditionally characterized by the sample variation coefficient, may be decreased to 8–12% by decreasing the porosity of the material and also by selection of the optimum machining conditions.