Heißgießen von drucklos gesintertem Siliziumcarbid. Herstellung der Heißgießschlicker

Based on the results of the investigation of stabilization of carbon black, boron and silicon carbide both in polar and apolar solvents several ways for adding the sinteractivating agents are possible. The preparation in water can be carried out either by homogenization of the separate solid-state compounds with negative surface charge or by heterocoagulation. In this case postive charged carbon particles coagulate to the negative charged SiC surface. The heterocoagulation can be detected by electrokinetic measurement at the raw materials suspension and the prepared suspensions of mixtures. The powder processing was carried out by separate wet homogenization of SiC and boron in a ball mill, producing the carbon black suspension in a solution of Alkylbenzyldimethyl- ammoniumchloride in water by ultrasonic treatment, mixing the suspensions and drying. To prepare the thermoplastic slip, the binder consisting paraffin, bees wax and diethanolamide of fatty acids was heated in a ball mill up to 100 o degree. Then the dried and heated ceramic powder was stirred into the melted binder. The prepared thermoplastic slip composition could be used for moulding immediately as well as cooled and stored.