... thermal expansion, good thermal shock resistanc, We supply boron nitride ( BN ) parts , which is a lubricant, high thermal conductivity, less thermal ... friction seals;Plasma arc insulators,Nozzle, etc.Main properties: Content :BN > 97.5%Density : 2.1-2.2 g/cm3Working temperature ... thermal expansion 2.0 x 10 -6 / K Boron nitride crucible