Development of Galvanic Pulse Deposited and Ultrasonic Shot Peening-Based Ni-Cr Hybrid Coatings

The ultrasonic shot peening (USSP) technique is being utilized as a reliable post-treatment process for various industrial parts to protect them from failures in their respective functions. The current study aims to develop nearly 10-microns-thick Ni-Cr alloy coatings to protect mild steel via a fast galvanic pulse deposition method and to enhance their mechanical and electrochemical properties through the different USSP process parameters as a hybrid technique. The morphological studies show the closure of cracks, better hardness, and scratch resistance of coatings after peening. XRD analysis confirms the presence of compressive residual stresses, along with the grain refinement and texturing effect after peening. After USSP, due to the presence of dimples average surface roughness has been increased up to 5 microns. The closure of pores and cracks and the hydrophobic nature of the coatings helped it to gain better corrosion resistance.