|
|
| | NIOBIUM BORIDE Basic information |
| | NIOBIUM BORIDE Chemical Properties |
| Melting point | 2270°C | | density | 7.500 | | form | gray orthorhombic crystals | | color | gray orthorhombic crystals, crystalline | | Resistivity | 40–64.5 (ρ/μΩ.cm) | | Crystal Structure | Orthorhombic | | CAS DataBase Reference | 12045-19-1 | | EPA Substance Registry System | Niobium boride (NbB) (12045-19-1) |
| Hazard Codes | Xi | | Risk Statements | 36/37 | | Safety Statements | 26-36 | | WGK Germany | 3 | | TSCA | TSCA listed |
| | NIOBIUM BORIDE Usage And Synthesis |
| Chemical Properties | gray powder(s); ortho-rhomb, a=0.3298 nm, b=0.872 nm, c=0.3166nm; resistivity 64.5μοhm· cm at 25°C; refractory material; commonly prepared by hot-pressing boron with niobium or niobium hydride; used as sputtering target with 99.5% purity to produce wear-resistant and semiconductor films, and can provide neutron absorbing layers on nuclear fuel pellets [KIR78] [KIR81] [CER91] [ALF93] | | Physical properties | Wear-resistant ; Major uses: semiconductive films,
neutron-absorbing layer on
nuclear fuel pellets | | Synthesis | 1, raw material preparation
The first step: niobium oxide powder with a particle size of 0.1μm, 3μm boron carbide powder and 3μm B2O3 powder were mixed uniformly in the ratio of 70:14:3 to obtain raw material powder 1.
Step 2: Mix the above raw material powder 1 with phenolic resin in the ratio of 5:0.5 by weight in a mixing mill, cure at a temperature of 80??C, and then pulverize in a pulverizer to make raw material powder 2 with an average particle size of 10μm.
Step 3: Mix the above raw material powder 2 with phenolic resin in the proportion of 5:1 by weight in the mixing mill, curing at a temperature of 50??, and then pulverized in the pulverizer to make the raw material powder 3 with an average particle size of 20μm.
Step 4: Mix the above raw material powder 3 with phenolic resin in the proportion of 5:2 by weight in the mixing mill, curing at a temperature of 40 ??, and then pulverized in the pulverizer to make an average particle size of 50μm raw material powder 4.
2. Synthesis of niobium boride powder
The above raw material powder 4 was briquetted under the pressure of 0.5Mpa, and then fired under argon atmosphere at the temperature of 1350??C for 6 hours to produce niobium boride block.
3. Decarburization
The above niobium boride block is decarburized by holding it in oxidizing atmosphere at a temperature of 350??C for 12 hours, and then crushed after cooling to produce niobium boride powder.
The purity of the raw materials used were 99.99% pure.
|
| | NIOBIUM BORIDE Preparation Products And Raw materials |
|