| Description |
ix, 69 leaves : illustrations (some colored) ; 29 cm |
| Summary |
"The zinc iron phosphate system is investigated for use as an enamel for the automotive industry. The thermal properties and chemical durability of the glass-forming region are measured. Compositions are selected based on their oxygen to phosphorus (O/P) ratio at values of 3.5, 3.25, and 3.0. Substitutions of SnO, CuO, Li₂O, Na₂O , K₂O for ZnO and B₂O₃ for Fe₂O₃ are used to alter the properties of the base glasses to achieve a particular range of T[subscript g], CTE and durability. The 3.25 and 3.0 O/P glasses are found have too low a durability to be used as an enamel. Within the 3.5 O/P glasses, high iron content produces too high a T[subscript g] to be useable. Of the lower iron glasses, the alkali modifiers are able to reduce T[subscript g] sufficiently without sacrificing CTE or durability. Li₂O increases the tendency of the glass to crystallize so that it does not re-melt and flow. A combination of Na₂O and K₂O provides the correct range of thermal properties and durability and SEM images show a consistent wetting of the substrate glass. The final glass composition chosen was 5Na₂O • 5Na₂O • 20.2ZnO • 21.8 Fe₂O₃ • 48 P₂O₅. The wetting experiments determined an optimum enameling treatment of 650°C for 5 min"--Abstract, leaf iii. |
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