Boron nitride seal for sealing planar oxygen sensor, especially lambda probe

摘要

A boron nitride seal comprises a moulded mixture of binder and hexagonal boron nitride powder obtained by comminuting hot pressed boron nitride material. An Independent claim is also included for production of a boron nitride seal by (a) collecting the powder debris from machining of components from hot pressed blocks of hexagonal boron nitride; (b) separating the 5-50 micro m diameter particles; (c) mixing the separated particles with a binder; (d) moulding the mixture to a sealing body; and (e) drying to evaporate the volatile components of the binder. Preferred Feature: The binder is an organic binder, especially an easily evaporated wax, optionally together with an inorganic binder such as aluminum phosphate.