Ceramic metal interface in laser deposited hard refractory composite coating: Electron microscopic study

Ceramic-metal interface plays the prime role in estimation of properties of composite and similar materials. In the present study, TiB2 has been depos ited on AISI 1010 steel using laser surface engineering (LSE) process. TiB2 /Fe interface is examined by electron microscopy (SEM and TEM) at microstru ctural and atomic level. A continuous, crack free and metallurgically bonde d coating is obtained which is "composite" in nature. TiB2 particles are ra ndomly distributed in Fe matrix without any preferred crystallographic orie ntation. High resolution transmission electron microscopy (HRTEM) shows tha t TiB2/Fe interface is atomically smooth and sharp with very little mismatc h. There is no evidence of cracking or delamination at the interface. Howev er, a small reaction zone of approximately 100 nm is formed at the interfac e as a consequence of non-equilibrium synthesis during LSE process.