The determination of oxygen in titanium, zirconium and their alloys

8 THE DETERMINATION OF OXYGEN IN ZIRCONIUM. TITANIUM AND THEIR ALLOYS 

In view of the very extensive similarity in the metallurgy and chemistry of these two metals and their alloys, they are considered together. 

The chemical affinity of oxygen for both systems is extremely high oxygen concentrations up to a few mg/g may be expected, the lowest figures being a few tens of ftg/g. The solubility limits (1000°C) are 1 at.% for P-Zr and 35 at.% fora-Ti, respectively (48). 

The first attempts to solve the problem of determining oxygen in these metals were based on their reaction with gases. Mention may be made of the reaction with hydrochloric acid gas at 450°C (135) and with chlorine gas at 800°C in the case of zirconium (135), or at 400°C in the case of titanium (136). The residue from this reaction contains the oxides, but also the carbides, which makes the determination extremely difficult. 

In a comparative investigation of methods for the determination of oxygen in titanium, Kysil and Engel (148) reach the following conclusions  

---