The development history, properties and application of silicon - calcium alloy are introduced
A binary alloy of silicon and calcium, belonging to the category of ferroalloys. Its main components are silicon and calcium, and it also contains different amounts of iron, aluminum, carbon, sulfur and phosphorus. Iron and steel industry used as calcium additive, deoxidizer, desulfurizer and denaturant of non-metallic inclusions. Used as inoculant and denaturant in the cast iron industry. Silica-calcium alloy according to calcium, silicon content is different to distinguish, other impurities according to different purposes have provisions. In addition, on the basis of silicon calcium alloy, other elements are added to form ternary or multivariate composite alloy. Such as Si - Ca - Al; Si - Ca - Mn; Si-Ca-Ba, etc., used as deoxidizer, desulfurizer, denitrification agent and alloy agent in iron and steel metallurgy. The following Xiaobian take you to know about it.
1. A brief history of silicon calcium alloys
Bozel, a French general-electrochemical company, began producing silicon calcium alloys in electric furnaces by electrothermal process and later by electrothermal process around 1907. China smelted silicon and calcium in a calcium carbide plant in Taiyuan in the 1950s. In 1964, Beijing Ferroalloy Factory successfully studied the smelting process of Si-Ca alloy by layered charging.
2.Properties of silicon calcium alloys
Calcium is an alkaline earth metal with an atomic weight of 40.08, an outer electronic structure of 4S2, a density of 1.55g/cm3 (20℃), a melting point of 839 4.2 ℃ and a boiling point of 1484℃. The relation between vapor pressure and temperature of calcium is:
LnpCa = 25.7691 20283.9 T - 1-1.0216 lnT
Where, PCA is the vapor pressure of calcium, Pa; T is temperature, K. Silicon and calcium form three compounds, Casi, Ca2Si and CaSi2. Casi (41.2%Si) is stable at high temperature. Ca2Si(29.5%Si) is a peritectic compound formed between Ca and CaSi at lower than 910℃. CaSi2(58.36%Si) is a peritectic compound formed between CaSi and Si at lower than 1020℃. The phase composition of the industrial Si-Ca alloy is about 77% CaSi2, 5% ~ 15% CaSi and Si free.
