Carburisation and other bake-on deposits are undesirable side effects that can arise during pressure sintering of diamond tools using graphite moulds, as well as when sintering high performance ceramics and carbides using graphite supports or other sintering jigs and fixtures. High friction induced stresses can arise between the sintered part and its support as a direct result of high contraction and differential thermal expansion and contraction rates within the sintered component. This can lead to the sintered components becoming distorted.
Boron nitride coatings prevent reactions from taking place at the contact surface between the sintered part and its support – at temperatures as high as 2000 °C and beyond. HeBoCoat® also acts as an excellent release coating for graphite supports and other sintering jigs and fixtures.
The exceptional properties of boron nitride are further exploited in sintering applications, both in powder form, using HeBoFill® as a bedding-in powder, and in sintered form using HeBoSint® crucibles. This ensures an even heat transfer to prevent the differential thermal expansions that can lead to the distortion of the finished sintered part.
Similarly, HeBoSint® sinter-charge carriers and distance pieces find frequent application in high temperature sintering processes where long service life and low maintenance are essential. These effectively protect against carburisation and contact reactions between the sintered part and its support.
We offer a broad spectrum of boron nitride products for a wide range of applications in the sintering and hard materials sectors. Depending on requirements, we can supply powders, suspensions, spray and machined sintered parts. We are also able to offer precision machined components, jigs and fixtures to customer requirements.