Influence of Adding Nano Coating Layers on the Hardness and Impact strength Properties for Low Carbon Steel

Abstract

Nanotechnology is one of the great techniques that helping to considerably improve many technologies and industry sectors such as information technology, homeland security, medicine, transportation, energy, food safety, and environmental science. Low carbon steel is widely used in many applications because it is cheap and it has high workability. However, low surface hardness and impact toughness are its main disadvantages. In this work, the nanocoating of tungsten carbide (WC) has been added to the low carbon steel surface with a thickness of 30, 40, and 50μm by using the thermal spray process with the HVOF technique. The present work aims to investigate the coating layer influence on the hardness and impact toughness. The results showed a significant improvement in the hardness, reaching 94.7%, while the impact toughness improved by 36% for a sample coated with a 50μm comparing with uncoated samples. The improvement in the hardness and impact toughness is due to the good adhesion of nano coat with the steel surface and the high hardness of tungsten Carbide as well as the good toughness of tungsten. The thickness of the coating layer is detected by using the scanning electron microscope images for each spray time. The results show that the coating with a layer of a thickness of more than 50μm will cause flaking and removing the coating layers.