Combating Metal Fatigue
Metal fatigue occurs when a metal component is weakened due to cyclic loading, the kind of forceful repetitive use that can cause the surface of the component to crack.
Today’s demanding mechanical processes – on the factory floor and in mission-critical parts for customer products – place high demand on component materials, so material and mechanical engineers face metal fatigue issues on a regular basis. They need reliable strategies and carefully documented design and repair parameters to increase fatigue life and prevent catastrophic failures. So how do engineers improve the fatigue life of metals?
Preventing Metal Fatigue in Engineering
Design: In order to keep the stress below the threshold of fatigue, engineers use models and experience to optimize the design of components for a long useful life. By prescribing the right alloy, thickness, shape, and grain consistency to meet cyclic loading requirements, they can ensure that metal fatigue will not lead to the overall failure of a system for the predicted life of the part. Crack growth calculations and nondestructive inspections are put in place to help ensure safety.
Testing: No component, however, is completely immune to metal fatigue failure. Materials scientists push parts to their limits, analyzing when cracks or corrosion start, and to help analyze the rate that cracks grow under a variety of realistic and simulated operating conditions. That testing helps pinpoint and explain more about failure locations and the origins of potential the cracking.
Repair: Repairing small cracks can help slow down crack growth and prevent catastrophic failure. Crack repairs are only a temporary remedy to metal fatigue. Drilling, blending, and patching are all ways that engineers repair crack growth on different surfaces of materials.