Depth distribution profile of martensite phase observed by transmission electron microscope in ion implanted metals

Abstract

In this work, transmission electron microscopy (TEM) observation results from a depth distribution profile of the nano-martensite occuring in titanium implanted austenitic stainless steel is presented. The thickness of 200 keV high-energy ion implantation induced layer until 150 nm as calculated by the TRIM computer simulation based on the Monte-Carlo program. After the implantation, the specimens were attached to thin foil ring to be milled by focused ion beam (FIB). TEM observation on the ion implantation induced layer reveled that nano-martensite is distributed until80 nm under surface. the nano-martensite mostly nucleated at the region near the surface occurred the higher concentration gradient of implanted ion, namely higher stress concentration takes place so that this stress introduced due to the implanted ions act as a driving force for the transformation.