Investigation of Heat Treated Electrodeposited CoNiFe on Microstructure and Hardness

In this research, heat treatment is the final finishing process applied on nanocrystalline CoNiFe to improve microstructure for good hardness property. Nanocrystalline CoNiFe has been synthesized using the electrodeposition method. This study investigated the effect of heat treatment at 500, 600, 700 and 800 °C on electrodeposited nanocrystalline CoNiFe. The heat treatment process was performed in the tube furnace with flowing Argon gas. In this paper, physical properties such as phase and crystallographic structure, surface morphology, grain size and hardness of nanocrystalline CoNiFe was studied by changing the heat treatment temperatures. The nanocrystalline CoNiFe phase revealed the Face Centered Cubic (FCC) and Body Centered Cubic (BCC) crystal structure. FESEM micrographs showed that the grain sizes of the coatings were in the range of 78.76–132 nm. Dendrite shape was found in the microstructure of nanocrystalline CoNiFe. The nanocrystalline CoNiFe prepared in heat treatment temperature of 700 °C, achieved the highest hardness of 449 HV. The surface roughness of nanocrystalline CoNiFe heated at 700 °C was found to be smaller than other temperatures.