Historical Perspective
Ronald Garvie and his team of researchers in Australia developed partially (P) stabilized (S) magnesium (Mg) zirconia (Z), Mg-PSZ, in the 1970s and named it “ceramic steel”. Materials science researchers worldwide followed quickly with numerous technical publications involving zirconia-based ceramics. Studies stretched into the 1990s. Among the best references are the series of volumes, “Science and Technology of Zirconia”. Since then, scientific fervor has slowly diminished seemingly because Mg-PSZ is perceived to be an “old technology”. Arguably, that might be so but significant production engineering challenges involving raw materials, binders for powders needed to press large parts, firing cycles to process parts in volume using large kilns, machining, etc. are not trivial. However, the “old technology” impression has some validity because for decades improvements to the properties of the original Mg-PSZ have not been demonstrated conclusively for industrial use. Structural applications were slow to develop for many reasons. Designers were unaware of Mg-PSZ, did not understand its advantages, or were reluctant to use it is because ceramics, unlike most metals, fracture easily, i.e. they “break”. The term, “ceramic steel”, in fact, precisely combats this perception. Also, highly demanding industrial technologies that might benefit from the use of Mg-PSZ were not yet mature and, in turn, commercial sources for the ceramic remained limited. Finally, if a ceramic was required, designers always turned to the well-established and readily available alumina, Al2O3.