Sintering of zirconia/430L stainless steel bilayers for co-powder injection moulding

To fabricate ceramic/metal complex-shaped part by co-powder injection moulding process (2K-PIM), it is essential to tailor the sintering parameters in order to gain a low mismatch shrinkage, i.e. high sintering compatibility. In the present work, nanocrystalline 3Y-TZP and commercial 430L MIM grade stainless steel powders were co-sintered at various sintering cycles. Isothermal and non-isothermal sintering behavior of the individual and composite layers in argon and vacuum atmospheres were examined. High resolution scanning electron microscopy (HRSEM) coupled with energy dispersive X-ray (EDX) analysis was used to study the bonding interface between the ceramic and metal joints. It is shown that the low difference in the coefficient of thermal expansion (CTE) and relatively low mismatch strain during sintering, a crack free joining is achievable. The analysis of the bonding zone indicated an interlayer diffusion of Zr, Fe and Cr, and a ternary Zr-Fe-Cr oxide interface during sintering.