Recently ion exchange, also known as chemical tempering, has been applied to strengthening of porcelain tiles based on the substitution of ions present in the material by larger ones. This paper investigates the chemical tempering in industrial porcelain tiles by the variation of process parameters such as temperature, immersion time, and chemical composition of the porcelain tile. Furthermore, a numerical simulation of the ionic diffusion process was applied. Using a design of experiments approach, the results show that the temperature and the chemical composition primarily affected the flexural strength of the tile. The largest increment obtained was 37 resulting in a porcelain tile with flexural strength of 73 MPa after chemical tempering. Through numerical simulation, it was possible to estimate a diffusion coefficient of potassium ions equal to 1.25 x 10(-14 )m(2)center dot s(-1) into the porcelain tile microstructure. This value is about 10 times higher than the diffusion coefficient in glasses.
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