Porosity; microhardness correlation of sintered (Al1-yCry)(2)O-3 solid solutions

Five out of the seven prevalent model mathematical equations resulted in be tter than the typical value of goodness of fit chi(2)=0.42 in the present l east-squares fittings of Vickers microhardness H-v to total porosity P-t fo r our sintered solid solution (Al1-yCry)(2)O-3 bodies of the system Al2O3-C r2O3. The best fit among the five turned out to the simple power function, H-v(GPa)=H-o(1-AP(t))(n)=29.382(1+8.585P(t))(-0.8663) With chi(2)=0.0137, a n excellent fit. The simple form of the function facilitated easy incorpora tion of open porosity P-o, closed porosity P-c and relative density d(r) as they are related by P-t = P-o + P-c and P-t = (1 - d(r)). The resulting H- v-P-t or H-v-d(r) relationships are graphically presented in detail. (C) 19 99 Elsevier Science S.A. All rights reserved.