MasazOkamoto and Renpei Yoda
Relations between the yield, true-or apparent-density, reaction time, hardness, microstructure as well as the chemical composition of the metallic mass obtained by the thermit processs and firing temperatures have been investigated in the manufacture of ferro-titanium containing 10∼60%Ti theoretically. The thermit reaction can be started at room temperature up to the powder from which 60%Ti alloy may be manufactured theoretically.
The larger the amount of TiO2 in the mixed powder is,the higher the appropriate temperatue giving the maximum yield as metallic mass rises; about 100° at 10%Ti-powder, 300° at 30%Ti-powder and 600° at 50%Ti-powder.
The concentration of titanium in the metallic mass is the highest and that of iron is the lowest at the firing temperature giving the maximum yield. The concentration of aluminum found in the mass obtained is almost proportional to that of titanium. Metallic mass from 30%Ti-powder does not so much decrease the yield at the over-preheaing of the charge because of the low melting point of the reduced product.
The higher the firing temperature is, the more both density and hardness as well as the content of titanium in the product increase. Percentage of titanium in the metallic mass obtained is about 50% of theoretical concentration of titanium. For example, the chemical composition of the metallic mass obtained from theoretical 30%Ti-powder at 300° is 15.78%Ti, 8.14%Al, 1.12%Si, Bal, Fe.
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