K, Ca, and Zn Ratios Affect Glass Frit Properties

Frites with mole fractions of ۲.۵ SiO₂, ۰.۲۰ Al₂O₃, ۰.۱۵ B₂O₃, ۰.۱۵ ZnO, ۰.۱۷ K₂O, and ۰.۶۷ CaO were studied at three different S ratios—۰.۳۷ (denoted as F۱ frits), ۰.۳۱ (F۲), and ۰.۲۴ (F۳)—where S = K₂O / (CaO + ZnO). ZnO powders of two different particle sizes were used as raw materials: ۵۰۰ nm (N series), obtained from recycled Zn ingot dust, and >۱ μm (F series), sourced from commercial ZnO. Upon decreasing the S ratio, the molar volumes of the frits decreased. The glass transition temperature difference (ΔTg = –۱۵۴ °C) decreased, whereas the crystallization temperature difference (ΔTp = +۱۷ °C) increased. It was shown that the glass stability (GS) values were independent of ZnO powder size, although the molar volumes of the N series were lower than those of the F series. Crystalline phases identified in the resulting glazes included zinc silicate (willemite), anorthite, and parawollastonite. The hardness values ranged between ۷۰۰ and ۸۵۰ Hv, while the glazes exhibited transparency and whiteness values exceeding ۸۰ and ۶۰, respectively.

کلیدواژه ها:

Glaze ، ZnO ، size ، Frites ، TEC