ZIRCONIUM DIOXIDE
Zirconium may be of two crystal types: a-form with hexagonal closed-packed lattice (and = 3,228; with = 5,120) and b-forms with cubic body-centred lattice (and = 3,61). Pure zirconium is plastic, easily gives in to cold and hot processing (a proskating proroll, forging, punching). Presence of the small quantities of oxygen dissolved in metal, nitrogen, hydrogen and carbon (or connections of these elements with zirconium) causes fragility of zirconium the Module of elasticity (20 °C) 97 gn/m2 (9700 kgf/mm2); strength at a stretching 253 Мн/m2 (25,3 kgf/mm2); Brinell hardness 640-670 Мн/m2 (64-67 kgf/mm2); on hardness very strong influence renders the contents of oxygen: at concentration more than 0,2 % zirconium does not give in to cold processing by pressure.
|
(Zr+Hf)O2 (min)™ |
99.5 |
|
SiO2 (max)˜ |
0.04 |
|
Fe2O3(max)˜ |
0.008 |
|
TiO2 (max)˜ |
0.0015 |
|
Na2O (max)˜ |
0.02 |
|
Al2O3(max)˜ |
0.0005 |
|
ZrO2+HfO2 |
SiO2 |
TiO2 |
Fe2O3 |
Al2O3 |
MgO |
CaO |
|
95.21 |
0.22 |
0.17 |
0.08 |
0.27 |
0.03 |
3.80 |
|
Химический состав (%) |
||||||||
|
ZrO2 |
Y2O3 |
SiO2 |
Na2O |
Al2O3 |
Fe2O3 |
K2O |
MgO |
Cl |
|
94.8+/-0.5 |
5.2+/-0.5 |
<0.045 |
<0.02 |
<0.01 |
<0.015 |
<0.01 |
<0.01 |
<0.08 |
