Member for crushing machine

PROBLEM TO BE SOLVED : To provide a member for a crusher that is improved in wear resistance, impact resistance and thermal impact resistance. SOLUTION : This member for crusher is a sintered product of silicon nitride composed of a β-silicon nitride crystalline phase and a grain boundary phase containing Y and/or a rare earth element, silicon, aluminum, oxygen and nitrogen. In addition, the ratio of the components is 75-95 wt.% of silicon nitride, 1-10 wt.% of Y and/or a rare earth element in terms of oxide, 0.01-5 wt.% of aluminum in terms of oxide and 10 wt.% or less of oxygen as impurity in terms of silicon oxide. Further, the density of 3.20 g/cm or more and the voids are 3% or less. Besides, the average void diameter is 5 μm or less and the void diameter distribution in such that the void diameter of 5-30 μm accounts for 30% or less, that of 30 μm or more accounts for 5% or less and that of 5 μm or less accounts for the remainder. Thus the sintered product made up of these voids dotted uniformly is used as the member of a crusher.