3.3. Microhardness distribution measurements
The microhardness measurements of non-peened, shot peened specimens are shown in Fig. 5. Maximum value
of microhardness is measured at the surface of shot peened specimen and then it gradually diminished to microhardness
of the matrix material. The value of maximum microhardness after shot peening is 201.29 HV. The
matrix material exhibits an average microhardness value of 146 HV. The values of microhardness of the surface
layer are increased about 37%. The values of microhardness from the surface to about 100ȝP decreases
significantly, while the values of microhardness from about 100ȝP to 300ȝP decreases slowly.