Identification and quantification of reaction phases at Si_3N_4-Ti interfaces by using analytical transmission electron microscopy techniques

摘要

Silicon nitride (Si_3N_4) and titanium (Ti) were successfully bonded by using a capacitor discharge joining method. The resulting sample interfaces were characterized by scanning electron microscopy (SEM) and analytical transmission electron microscopy (TEM) techniques. SEM and chemical analyses by energy dispersive X-ray spectrometry (EDX) and wave length X-ray spectrometry (WDX) showed that if there is a reaction layer it is very small. Sample preparation from metal-ceramic joints for TEM by using conventional techniques is difficult. To overcome this problem, samples were prepared by using a focus ion beam (FIB) and investigated by TEM techniques. Analytical TEM techniques such as electron energy loss spectroscopy (EELS) revealed that Si_3N_4 interacted with Ti and reaction phases were formed at the interface. These phases are approximately 50 nm thick Ti_3N_2 layer at the interface next to Si3N4 followed by continuous Ti_6Si_3N phase as a matrix containing Ti_3N particles.