+ higher values can be obtained when lower indenter loads are used during Vickers hardness measurements (reference 10).
[All our mechanical tests were carried out on UHM's CeTZP billets. A LECO test machine for our indentation macrohardness tests utilized 30 kg loads; K1c values were calculated from crack lengths derived from these indentation tests using the equation of Anstis el alia (reference 10)]
UHM’s CeTZP engineering ceramic has some clear mechanical property advantages over Silicon Nitride and they are:
The fracture toughness of UHM’s CeTZP is about three times (or 300%) higher than Silicon Nitride. This means that UHM’s CeTZP is less likely to fracture under higher load-bearing conditions than Silicon Nitride
The Bend Strength of UHM’s CeTZP is higher than that of Silicon Nitride
CeTZP engineering ceramic has some thermal property advantages over Silicon Nitride and they are:
The thermal expansion coefficient of CeTZP is comparable to that of cast iron (Silicon Nitride has a much lower thermal expansion coefficient which would make Silicon Nitride a mismatch with cast iron)
CeTZP has a lower thermal conductivity than Silicon Nitride. Thus, CeTZP is a better candidate material than Silicon Nitride for heat engines.