Improvements in and relating to materials of high strength and resistance to molten metals and slags at elevated temperatures

摘要

A sintered cermet comprises W and/or Mo and an oxide ceramic phase consisting predominantly of ZrO2, the cubic phase of which is stabilized by additions such as 4 to 10% by weight of CaO or MgO. The metal phase comprises 20 to 85% by volume of the composition and may contain Cr up to 50% by weight of the metal content. The oxide phase may contain up to 50% of its volume of HfO and/or TiO2 and/or ThO2. Sintering of the compacted powders is carried out at 1700 DEG -2100 DEG C. and thermocouple sheaths, casting nozzles and tun dish stoppers may be made from the cermet.ALSO:A sintered cermet comprises W and/or Mo and an oxide ceramic phase consisting predominantly of ZrO2, the cubic phase of which is stabilized by additions such as 4 to 10% by weight of CaO or MgO. The metal phase comprises 20 to 85% by volume of the composition and may contain Cr up to 50% by weight of the metal content. The oxide phase may contain up to 50% of its volume of HfO and/or TiO2 and/or ThO2. Sintering of the compacted powders is carried out at 1700-2100 DEG C.