Premium
Investigation on Properties of Fluorine‐Free Mold Fluxes Based on CaO–Al 2 O 3 –B 2 O 3 System
Author(s) -
Li Jiangling,
Kong Bowen,
Galdino Bruno,
Xu Jifang,
Chou Kuochih,
Liu Qingcai,
Shu Qifeng
Publication year - 2017
Publication title -
steel research international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.603
H-Index - 49
eISSN - 1869-344X
pISSN - 1611-3683
DOI - 10.1002/srin.201600485
Subject(s) - crystallization , mold , materials science , fluorine , flux (metallurgy) , melting temperature , viscosity , casting , analytical chemistry (journal) , metallurgy , mineralogy , thermodynamics , chemistry , composite material , chromatography , physics
Fluorine‐free mold flux has received ever increasing attentions due to environmental problems cause by fluorine in casting. Fluorine‐free mold fluxes based on CaO–Al 2 O 3 –B 2 O 3 systems are developed in the present work. The melting temperatures, viscosities, and crystallization behaviors of CaO–Al 2 O 3 –B 2 O 3 based mold fluxes are investigated. The results show that the melting temperatures decrease with the increasing B 2 O 3 and Na 2 O content, while the melting temperatures of mold fluxes first increase with increasing CaO/Al 2 O 3 mass ratios, and then decrease with further increasing CaO/Al 2 O 3 ratios. The viscosity values of mold fluxes decrease with increasing of B 2 O 3 , Na 2 O content, and CaO/Al 2 O 3 ratio. The crystallization temperatures of mold fluxes decrease with the increasing B 2 O 3 and Na 2 O, while the crystallization temperature of mold fluxes first increases with increasing CaO/Al 2 O 3 mass ratios, and then decreases with further increasing CaO/Al 2 O 3 ratios. XRD and SEM are used to analyze the sequence of crystallization. Ca 3 Al 2 O 6 crystals are precipitated at first, followed by LiAlO 2 during continuous cooling for all samples, and Ca 3 B 2 O 6 is precipitated finally. It is shown that CaO–Al 2 O 3 –B 2 O 3 based mold flux has a potential to be applied as a kind of F‐free mold flux.