Formation of Wear-Resistant Nanocomposite Layer on Aluminum

In structural applications where surface contact is involved the performance and useful life of suitable materials are mainly determined by their surface properties such as wear resistance and hardness. Aluminum-based materials are attractive for these types of structural applications in the aerospace, military, and transportation industries due to their light weight, high strength-to-weight ratio, and good corrosion resistance. However, the applications for aluminum-based materials are significantly limited, due to their poor surface properties, such as poor wear resistance which is evidenced as severe adhesive wear. Other materials, such as magnesium and titanium, also suffer from poor wear resistance, and therefore, applications with these materials are similarly limited.

Al₂O₃-Al composites containing a relatively high concentration of Al₂O₃ nanoparticles have been found to exhibit superior wear resistance by showing both significantly lower wear rates and desired abrasive wear. However, direct usage of these bulk nanocomposites is limited because of the resulting reduction in ductility and thermal conductivity. Furthermore, bulk processing typically used to manufacture Al₂O₃-Al composites is time and energy intensive. There is a need for improved nanoparticle-reinforced composites that provide a hard, strong, wear-resistant surface while maintaining the ductility and thermal conductivity of the substrate material that, by itself, otherwise has poor surface properties.

Dr. Cheryl Xu invented a method of surface enhancement that binds a hard wearable surface and ductile metal substrate without introducing an interface between them. The interface between these layers is often very weak. Dr. Xu’s method solves this problem and creates composites with strengthened wear resistance and surface hardness. This is accomplished while maintaining good ductility and thermal conductivity.

Advantages

• Efficient manufacturing
• Eliminates de-bonding inherent in other surface coating techniques
• Easily applied to selected areas
• Low cost
• Process can be applied to non-flat surfaces
• Strengthened wear resistance and surface hardness while maintaining good ductility and thermal conductivity