**Parametric Variables in Electro-deposition of Composite Coatings**

Peter Odetola, Patricia Popoola, Olawale Popoola and David Delport

Additional information is available at the end of the chapter

http://dx.doi.org/10.5772/62010

#### **Abstract**

Nowadays, synergy of the attractive properties of materials while avoiding limitations of their use in isolation is a major driver for flexibility in design and manufacture. This al‐ lows tailoring of materials' properties to meet specifications. Composite technology uti‐ lizes an excellent combination of properties: strength, stiffness, light weight, wear, chemical, corrosion, and temperature resistance, which transcend those of the constituent materials. Engineering structures, equipment, and vessels in key industries that are mate‐ rial-dependent are susceptible to deterioration process and damage over time in their service conditions. Composite coatings through electro-deposition offer a reliable cost-ef‐ fective means of impacting special surface properties for corrosion protection, better ap‐ pearance, and mechanical properties' enhancement. The properties of the composite coatings can be optimized by varying the type, size, amount and distribution of the parti‐ cles content incorporated among others.

**Keywords:** Co-deposition, Nano-particles, Current density, Micro-hardness, Agglomera‐ tion, Metal deposit and Microstructure

**1. Introduction**

#### **1.1. Composite coating**

A composite coating is a multi-phase coating with well-controlled phase distribution and geometry to optimize the properties of the matrix phase and reinforcement co-deposited phase or phases. Composite coatings have been used to achieve combination of specific properties of corrosion and wear resistance, corrosion inhibition and electrical conductivity, tribological control and self-lubrication. At times, two apparently opposed properties are specified such as high tensile strength and at the same time high ductility. The most common applications

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include controlling corrosion of various structures like steel, bridges, offshore platforms, underground pipelines, and mechanical driving equipment.

#### **1.2. Nanotechnology applications in composite coating**

Based on the principles that govern material behavior, it has been established that a material or device with particles size less than 100 nm length is in the nanotechnology domain. These particles primarily promote the mechanical and metallurgical properties of composite coatings in the areas of micro-hardness, corrosion resistance and tribological control and frictional and wear properties. Therefore, nanotechnology helps in characterizing the co-deposit of compo‐ site coatings to enhance specific features in the coating formulation.

Nanotechnology applications in coatings have gained tremendous ground in research and developments in recent years. This is a result of two factors:

