The near surface changes in boron implanted 4145 steel

Boron implanted 4145 steel was evaluated for changes in the near-surface region property such as microhardness. The surfaces when implanted with 11B+ ions at 135 keV energy to a dose 1 x 1017 ions cm-2 resulted in increase of microhardness for 10 to 40 gm of applied load. An increase up to 40% in microhardness could be observed in the specimen when annealed at 310degC for 3 hours. Furthermore, the effect of ion-beam induced intermixing of 250A thin carbon film due to boron implantation was also studied for different doses ranging from 1 x 1017 to 3 x 1017 boron ions cm-2. An increase in microhardness with applied load was observed for 1 x 1017 ions cm-2 concentration, while hardest layer was formed at 3 x 1017 ions cm-2 dose which practically had very little effect to 10 and 20 gm of load. (author)