Electropolishing: How to Improve Fatigue Life of Metal Parts

Maximizing the Longevity for Critical Metal Parts

Electropolishing has become a common metal finishing process used to help improve the life of metal parts that flex, cycle, twist and bend. These components come in many forms, including stampings, wire forms, laser-cut tubes and even machined parts. During the manufacturing process, micro defects on the surface of these components are left behind. These defects, often in the form of microcracks or pits, can become initiation sites for crack propagation or corrosion.

Electropolishing to Eliminate Imperfections

Electropolishing and fatigue life improvement

By removing these imperfections on the surface of metal parts, engineers have found electropolishing to greatly improve the life of components that function as springs.

The figure to the left shows how a small crack or notch can create a condition that will result in failure as stresses are placed along the surface of a part. This “notch effect” can be mitigated by removing a small amount of material from the surface of the metal part, restoring its surface to a smooth, defect-free surface. Able Electropolishing processes millions of springs each year made from music wire, stainless steel 300 series, 400 series, and Nitinol, in order to improve their performance.

Meeting Stress Requirements in Critical Parts

Able Electropolishing frequently processes stamped parts that must flex and torque as part of regular use. Electropolishing these parts helps them meet their life cycle expectations.

One customer experienced a problem with a part stamped out of heavy gauge material, which was not meeting its stress requirements. The stamping process left the part with small cracks and fissures, which compromised the part with repeated use.

By electropolishing the part, Able removed enough surface material to eliminate the fissures, enabling the part to pass its rigorous testing and function longer.

Electropolishing Stainless Steel Springs and More

Stainless steel springs and wire forms are prone to the same development of cracks and fissures that lead to premature part failure. When electropolishing stainless steel parts like these, Able removes a uniform layer of surface material from the entire part, stripping away the surface imperfections and cracks that threaten the part’s performance. After electropolishing, springs and wire forms meet or exceed their anticipated cycle levels.

Contact us to learn more about electropolishing and extending metal part life