Zirconium diboride possesses attractive properties, such as, high melting point, high temperature strength, good thermal conductivity, high electrical conductivity and considerable chemical stability. ZrB2 is known asan ultra-high temperature ceramic (UHTC) material. Potential applications of ZrB2 are thermal protection system for aerospace applications, high temperature electrodes, molten metal crucibles and wear resistant coatings. The technologies were developed to (i) synthesize ZrB2 powder by solid state reaction technique using zirconium dioxide, boron carbide and carbon, and (ii) Densification of ZrB2 powder into flat shaped geometries such as pellets, discs etc using hot pressing technique. Micron sized ZrB2 powder is produced after subjecting the synthesized ZrB2chunk into series of grinding stages. The as-produced powder is subsequently used for hot pressing.

ADVANTAGES
    ZrB2 is having high melting point, high temperature strength, good thermal conductivity, high electrical conductivity, low coefficient of thermal expansion and stability in extreme environment.
    The synthesis process involves carbothermic reduction of zirconium dioxide in presence of boron carbide. The process is economical, reliable and reproducible compared with other techniques like wet chemical methods, gas phase reactions etc.
    Technology developed using inexpensive raw materials.
    ZrB2 powder with greater than 99% purity is produced.
    ZrB2 shapes of ~99% of theoretical density are prepared.

APPLICATIONS
    Thermal protection system, leading edges, nose caps of hypersonic re-entry vehicles
    Aerospace and aeronautical applications such as high pressure turbine shrouds, exhaust nozzles, combustor liners, turbine blades, vanes, rocket motors, bearing seals
    High temperature electrodes, plasma arc electrodes
    Molten metal crucibles
    Wear resistant coatings, Neutron absorbersetc.

INTRODUCTION

Zirconium diboride possesses properties as high melting point, high thermal conductivity, good thermal shock resistance, low coefficient of thermal expansionand stability in extreme environments. Its potential applications are thermal protection system for re-entry vehicles, hypersonic flights, molten metal crucibles and high temperature electrodes.The technologies were developed to (i) synthesize ZrB2 powder by solid state reaction technique using zirconium dioxide, boron carbide and carbon, and (ii) Densification of ZrB2 powder into flat shapes using hot pressing technique. Micron sized ZrB2 powder is produced after subjecting the synthesized ZrB2 into series of grinding stages. The as-produced powder is subsequently used for hot pressing.

ADVANTAGES

    ZrB2 is having high melting point, high hardness, good thermal conductivity, low coefficient of thermal expansion, retention of strength at high temperature and stability in extreme environment.
    The synthesis process involves carbothermic reduction of zirconium dioxide in presence of boron carbide. The process is economical, reliable and reproducible compared with other techniques like wet chemical methods, gas phase reactions etc.
    Technology developed using inexpensive raw materials.
    ZrB2 powder with greater than 99% purity is produced.
    ZrB2 shapes of ~99% of theoretical density are prepared.

APPLICATION

1)    Thermal protection system, leading edges, nose caps of hypersonic re-entry vehicles
2)    Aerospace and aeronautical applications such as high pressure turbine shrouds, exhaust nozzles, combustor liners, turbine blades, vanes, rocket motors, bearing seals
3)    High temperature electrodes, plasma arc electrodes
4)    Molten metal crucibles
5)    Wear resistant coatings, etc.
6)    Neutron absorbers
RAW MATERIALS
Raw materials are easily available in the local market. NFC is manufacturer and supplier of ZrO2
INFRASTRUCTURE
The preparation of Zirconium diboride powder is carried out in a high vacuum induction or graphite resistance furnace.Micron sized ZrB2 powder is produced by using the series of grinding stages, which requires vibratory cup grinding mills. High vacuum, high temperature, hot pressing is required to prepare the dense flat shapes.In addition, turbo mixer, vacuum oven, semi-automatic hydraulic press, graphite dies, graphite insulation materials, weighing balance, heater plate, DM water are required.

MANPOWER

The manpower requirements depend on the capacity and the extent of automation. However, one engineer& two technicians are sufficient to start production.