| 摘要 |
PURPOSE:To obtain a friction material having improved strength by thermoforming a material for the friction material which incorporates bulk mesophase carbon and steel fiber, and thereafter heat-treating it in the hydrogen atmosphere. CONSTITUTION:Material for a friction material contg. both bulk mesophase carbon as a binder and steel fiber as reinforcing fiber is thermoformed in a hot press method. Then the aimed friction material is obtained by retaining this thermoformed material for the friction material at 1,050-1,150 deg.C for 10-40min in the hydrogen atmosphere. This heat-treatment of the thermoformed friction material in the hydrogen atmosphere is performed in order that an oxidative film on the surface of steel fiber is reduced and removed and thereby carbon is easily infiltrated into fiber. Further the above-mentioned heating is performed because steel fiber is not carburized in the case of <=1,050 deg.C and <=10min and excessively carburized in the case of >=1,150 and >=40min. Furthermore when unnecessarily raising the heating temp., the service life of a heat- treating furnace is shortened and consumption of energy is made large and also when the heating time is unnecessarily prolonged, it is made nonfavorable industrially. |
