Paper Title
Investigation of Nano Graphene Coating Effect on Micro-hardness Profile and Microstructure Characterization of St37 Steel by Friction-Stir-Processing Method

In this research, 3 types of samples micro-hardness were investigated: 1. Friction Stir Processed (FSP) samples coated with Graphene Nano particles; 2. FSPed samples without any particle; 3. The Base Metal (BM). Then, the effect of applying FSP on St37 steel Micro-hardness with Graphene Nano-particles was investigated and then compared to the one of samples without any particle and the BM. In all FSPed samples, rotational and traverse speed were considered 900 rpm and 100 mm/min, respectively. All experiments were done in the same total dominant conditions. It is notable that Micro-hardness of three produced fabrication zones (Nugget Zone, TMAZ, HAZ) in both FSP Nano-coated sample and FSPed sample (without any particle) showed a great promotion in comparison to the one in BM. But, this promotion is not extended homogenous and equivalent in all three parts (Nugget Zone, TMAZ, HAZ) and in both two different samples (with and without Nano particles). Nugget zones experienced the biggest amount of promotion in Micro-hardness value in both FSP Nano-coated samples and FSPed samples. In addition, the FSPed Nano-coated samples allocated greater promotion slope to themselves. By comparing the three produced fabrication zones; it’s concluded that coating Nano Graphene particles by FSP caused greater difference rather than the other samples. Keywords - Friction Stir Processing, Graphene, St37 Steel, Micro-hardness.