What is the focus of surface hardening?

The focus of surface hardening is to enhance wear resistance while maintaining resilience. This process involves modifying the surface characteristics of a material, usually metals like steel, to create a harder surface layer while retaining the toughness and ductility of the inner material. The hardening improves resistance to wear and abrasion, which is especially important in applications where components are subject to friction and contact with other surfaces, such as gears, bearings, and cutting tools.

Maintaining resilience is crucial because it ensures that the component can absorb energy and withstand impacts without cracking or breaking, which is vital in many engineering applications. By achieving a balance between hardness and toughness, surface hardening techniques, such as carburizing or nitriding, contribute significantly to the lifespan and effectiveness of engineering components.

The other options do not encapsulate this objective accurately. While creating a uniform medium-strength material, producing highly brittle steel, or improving thermal conductivity could be relevant to certain processes or properties of materials, they do not directly align with the primary goal of surface hardening, which is specifically about enhancing surface wear resistance without compromising the material's ability to endure stress and maintain its structural integrity.