In this study, alloyed layers of 1.5-1.8 mm thickness were formed on the Cu based material surface using the Gas Tungsten Arc welding (GTAW) process. After the preliminary studies and sample preparation as groups I, II, and III, the surface alloying process was performed with 115 A, 125 A and 140 A current values, 6 g, 9 g and 12 g powder feed contents, and by determining voltage coefficients at 25 V and 28 V, respectively. Penetration of ferromanganese on the underlay was ensured using optimized coating parameters. In the ferromanganese layer different hardness values were determined according to the amount of powder fed. These hardness values were correlated to the thermal conductivity of Cu at the respective energy input. The impact resist of the coated specimens was increased. These toughness increments were attributed to newly formed structures in the microstructure with the effect of thermal conductivity and hardness of coated surface. Changes in powder feed time and powder feed rate and energy input were calculated from application parameters.