Low porosity glass coatings formed on coiled wires, high temperature devices containing the same, and methods for the fabrication thereof

A method for producing a high temperature electromagnetic device, the method comprising:

• forming, over an outer surface of a wire, an intermediary glass coating at least predominately composed of a first glass, by weight, the first glass having a first Coefficient of Thermal Expansion (CTE), forming comprising:
• applying a glass coating precursor material onto the wire, the glass coating precursor material containing particles composed of the first glass;
• and
• performing an intermediary heat treatment process to consolidate the particles composed of the first glass into an intermediary glass coating;
• infiltrating the intermediary glass coating with a filler glass precursor material, the filler glass precursor material containing particles composed of a second glass having a second CTE substantially equivalent to the first CTE;
• and
• after infiltrating the intermediary glass coating with the filler glass precursor material, performing a densification heat treatment process to consolidate the particles composed of the second glass into the intermediary glass coating and yield a low porosity glass coating adhered to the wire.

A high temperature electromagnetic device, comprising:

• a wire coil having a core composed of a material having a first Coefficient of Thermal Expansion (CTE);
• a low porosity glass coating adhered to the wire coil and having a second CTE greater than one half of the first CTE;
• a container in which the wire coil and the low porosity glass coating are located;
• and
• an inorganic potting material at least partially filling the container, contacting the low porosity glass coating, and having a third CTE less than the second CTE.