| 摘要 |
1477767 Moulding abrasive tools EDENVALE ENG WORKS (PTY) Ltd 22 Sept 1975 [23 Sept 1974] 38854/75 Heading B5A [Also in Division B3] The working portion of an abrasive tool is made by mixing acicular abrasive particles (preferably having a length : width ratio of at least 3 : 1) with starting materials for a bonding matrix, pouring the mixture into a mould, applying a force field to the mixture while it is being poured so as to align a substantial proportion of the particles with their long axes substantially normal to the face which will form the working surface of the tool, and causing the bonding matrix to set, at least partially, around the aligned particles. The particles are preferably diamond or cubic boron nitride, and the bonding matrix is preferably a resin. The applied field may be electrostatic, but is preferably magnetic, in which case the abrasive particles, if non- magnetic, must first be coated with a magnetic metal, preferably nickel. |
