edge hardening
Edge hardening is a process of heat treatment in which mainly edges or surfaces of specific areas of a metal part are hardened. It is most generally applied to components such as blades, cutting tools, and gears, where the edge must wear while having a tough interior portion to absorb shock and prevent brittle fracture.
Key Features:
- Selective Treatment: Edge hardening treats only the working edge of a part and offers further ways to improve efficiency and material use as opposed to full-body hardening.
- Wear Resistance: The hardened edge considerably increases the durability and performance of the component in an abrasive or cutting environment.
- Core Toughness Maintained: Given that the inner material remains soft and ductile, edge-hardened parts crack and fail even under the highest impact or stress.
Edge hardening plays a significant role when considering the life extension of tools and mechanical parts. For example, knives with hardened edges will remain sharper while not being highly breakable because the core is softer, and edges have a great tendency to sharpen further. Teeth with edge hardening in gears contact each other continuously and experience friction in machinery without rapidly wearing away. Therefore, surface hardness and core toughness together make edge hardening an important process for manufacturing industries like automotive, aerospace, and toolmaking.