Method of forming glass bonded joint of beta-alumina

A method of producing a joint between a body of beta-alumina and a body of alpha-alumina with a glass bonding agent devoid of coupling additives capable of being heated when subjected to microwave energy, wherein the glass bonding agent is applied in the form of a solid body to a surface of said beta-alumina body and a surface of said alpha-alumina body which comprises

• subjecting said beat-alumina body and said alpha-alumina body with said glass body engaged to said surfaces thereof to microwave energy from a microwave source so as to heat said beta-alumina body by microwave energy for a time period sufficient to enable the heat generated in said beta-alumina body to be conducted to said glass body and said alpha-alumina body and heat the glass body to a temperature above the glass deformation point, and
• allowing the bodies to cool to solidify the glass body in intimately penetrating relation to the surfaces of the beta-alumina and alpha-alumina engaged thereby so that the glass body forms a bond between the beta-alumina body and the alpha-alumina body characterized by a fusion of the glass within the engaged beta-alumina and alpha-alumina,
• the time period to which the bodies are subjected to microwave energy being not substantially longer than that required to heat the glass to said deformation point of the glass.