Abstract: Before suferfine comminution,the pre-treatment,pressurization of pig bone is required. Evidently,the hardness of treated bone varies with pressurization conditions. In this study,the perpendicular shear force and extrusion force and Paralle extrusion force and parallel extrusion force of the treated bone were analyzed according to the principle of the used HMB-701 type micronizer,and then the failure stress was calculated. This could not only simplify the process of analysis,but also reveal the effects of different pre-treatment conditions on the hardness of bone. Futhermore,the best pretreatment technology could be obtained. According to experimental results,the best pre-treatment technology is determined as treating pig bone for 60 min at 0.15 MPa.

Key words: bone powder, superfine comminution, per-treatment, failure stress