According to the invention, the composition contains an abrasive material (12.5-37.5 vol.-%), a metallic filler (30-60 vol.-%), a mineral binder (5-30 vol.-%) and the balance is an organic binder. The mineral binder is constituted by at least one substance from a group of salts whose melting temperature corresponds to the temperature range of polymerization of the organic binder.
A cutting member to be connected to a material removing device such as an annular bit, a drilling bit, a cutting bit, a saw and the like, consists of a binder agent, diamond grains and a small amount of hard material particles. The hard material particles reinforce the binder agent and supports the anchorage of the diamond grains.
Magnesium oxychloride cement bonds are improved by incorporation of graphite. The graphite not only contributes to cooler dry grinding with abrasive tools based on the magnesium oxychloride bond, but unexpectedly also improves heat strength of the bond.
Magnesium oxychloride cement bonds are improved by incorporation of graphite. The graphite not only contributes to cooler dry grinding with abrasive tools based on the magnesium oxychloride bond, but unexpectedly also improves heat strength of the bond.
A method for making vitreous bonded grinding wheels having a porosity of from 20 to 55% by volume is provided that reduces or prevent shrinkage. The method includes a step of mixing unclad, non-abrasive, non-metallic, particulate, inorganic solid shrinkage control agent with the abrasive grain, vitreous matrix precursor and other ingredients for producing the wheel. Non-abrasive hexagonal boron nitride is a preferred shrinkage control agent and may be used in amounts ranging for 1 to 10% by volume based on the volume of the grinding wheel. Reduced shrinkage of wheels made by the method over comparable wheels made without the shrinkage control agent is obtained.
