Ceramics-Silikáty 39 (4) 145-154 (1995)

INFLUENCE OF PRESSURE ON THE INTERACTION BETWEEN ALUMINA - MULLITE SHELL MOULDS AND MOLTEN NICKEL ALLOYS

J. Cihlář, K. Maca, P. Marquis

The interaction of ceramic alumina-mullite mould with nickel and nickel alloys (ZhS6K, NiTi and NiCr) was studied at a temperature of 1773K in the pressure range from 0.1 to 10⁵ Pa. The ceramic mould contained a continuous network of pores, which provided for the releasing of the gaseous phase at the mould(s)/metal(l) interface and thus facilitated physical and chemical erosion of the face layer of the mould at low pressures. Increasing the pressure of gaseous atmosphere to over 10⁴ Pa practically prevented the erosion of mould surface by nickel and its alloys.