Abrasive tools prodn. by hot pressing - using bimetallic plates to apply pressure

摘要

Process for producing abrasive tools comprises heating an abrasive mass contg. a phenol-formaldehyde resin ("bakelite") binder to liquefy the resin, and then simultaneously heating and pressing the mass at a fixed pressure to compress the mass and harden the resin. The pressure is applied by means of bimetallic plates which bend when heated. The plates must have a specific bending coefft. (A) of >=0.2 deg-1 (A = fS x 104/t2-t1).l2, where f is the deflection of the free end of the plate; S is the thickness of the plate; l is the length of the plate; t1 and t2 are the initial and final temps). The process can be used to mfr. grinding discs for high-speed working of steel and alloys under high loads. It allows pressing and heat treatment to be effected simultaneously under controlled conditions, giving increased productivity and improved product quality.