the present application is directed to a zirconia toughened alumina body and process for making the body . the process involves combining tetragonally stabilized zro 2 nanoparticles , mg 2 particles and alumina powder into a mixture . all particles of the mixture are milled , formed into a green compact and then sintered . the final composition of the body includes α - al 2 o 3 toughened with 0 . 5 to 2 . 5 weight percent zro 2 in a stabilized tetragonal form and 0 . 03 to 0 . 10 weight percent mgo . the composition results in an al 2 o 3 body with a density less than 4 . 0 g / cc and strength greater than 50 kpsi .