Determination Of The Influence Of The Mixing Quality On The Grinding Tool Bond After Sintering

The powder mixture properties determine the sintering result of vitrified bonds for grinding tools. In this paper the influence of the mixing process on porosity of the sintered bonds through the bulk density is shown. Therefore, the bulk density of the mixture and the abrasive concentration and sintering temperature and holding time were varied. Porosity, shrinkage and bending fracture stress were determined to evaluate the influence of these parameters on the sintering result. It was shown that there is no significant influence of abrasive concentration, sintering time and temperature on porosity, shrinkage and bending fracture stress. Instead it was shown, that abrasive concentration has a negative influence on the porosity of the powder mixture. With increasing the concentration from two to ten Vol% the porosity of the powder decreases at about 1.6 Vol%. Further the shrinkage has also a negative influence on the porosity of the sintered pellets. Here, with increasing the shrinkage about six Vol% the porosity of the sintered pellets decreases about four Vol%. These outcomes are important for designing moulds and optimizing sintering results.