Aircraft place hefty demands on bearings to enable smooth rotation and support loads across many assemblies while exhibiting high strength, resistance to wear, corrosion tolerance, and the ability to perform under extreme temperatures and stresses. Because of these challenges, the choice of bearing material directly influences how reliably it will perform in its intended area. To help guide your selection, this guide will outline the properties of the most common materials used to create aerospace bearings.
Stainless steel performs very well under varying environmental conditions, able to withstand moisture, corrosive substances, and temperatures up to approximately 570°F. Additionally, it boasts a relatively cost-effective production compared to more exotic alloys while still displaying remarkable tensile strength and fatigue resistance. These properties make it a versatile option for raceways and rolling elements in many forms of bearings. However, stainless steel is heavier than some alternative materials, which is a major drawback in weight-sensitive areas.
Chrome steel, particularly AISI 52100 grade, is one of the most widely used materials for aerospace bearings due to its combination of high hardness, wear resistance, and excellent fatigue life. It performs reliably under continuous high-load conditions, which makes it especially suitable for rolling element applications.
Typically rated for operating temperatures up to 300–390°F, chrome steel can maintain its structural integrity well, but it is more limited in corrosion resistance compared to stainless steel. Additionally, chrome steel bearings are highly dependent on stringent lubrication practices, as a lack of lubrication can lead to surface damage or premature fatigue.
Titanium alloys are highly regarded in aerospace applications for their exceptional strength-to-weight ratio, making them valuable in designs where minimizing overall aircraft mass is a priority. In addition to their lightweight properties, titanium alloys exhibit strong corrosion resistance and can operate at elevated temperatures up to 930°F. The trade-off is that titanium does come at a higher cost, both because of the raw material and the complicated processes required for machining and finishing it.
Ceramic materials like silicon nitride and zirconia are highly valued in aerospace for their thermally stable, corrosion-resistant, and lightweight properties. More than that, ceramics can operate at very high speeds with minimal lubrication, a significant advantage in demanding aerospace environments. The limitations of ceramic materials are mainly that they are more brittle compared to metals and specialized, more expensive manufacturing processes are required to produce reliable bearings from them.
Bronze and copper alloys are primarily employed in bushings and plain bearings, where sliding rather than rolling contact occurs, featuring moderate load-carrying capacity, consistent wear resistance, and compatibility with various lubricants. Another benefit of these alloys is their relative ease of manufacturing, which keeps costs lower. They are also adaptable to different bearing designs, with tweaks in alloy composition enabling improved resistance to galling, seizure, or fatigue under specific conditions.
Because their mechanical strength and usable temperature range is narrower than other material options, bronze and copper alloys cannot perform in environments where extreme heat is present or fast, heavy-load operation is needed. Moreover, such bearings also generally require consistent lubrication to ensure a long service life under operational stresses.
Selecting the appropriate material for an aerospace bearing does not follow a one-size-fits-all rule, needing careful evaluation of the environment in which the bearing will operate, the type of loads it must endure, and the performance expectations placed upon it. For instance, bearings used in engine systems face very different stresses compared to those in landing gear assemblies or control actuators. As such, aircraft designers and technicians will match a material’s inherent strengths to the specific application at hand.
In summary, the choice of bearing material is not a simple matter of preference, instead directly influencing the safety and performance of the systems they serve in. Selecting the appropriate material is only one part of the equation, with a reliable source for high-quality bearings being equally critical. On Stacked Purchasing, you can peruse a wide selection of bearings for different needs, all of which are sourced from trusted manufacturers.
As an ASAP Semiconductor website, we uphold rigorous quality-assurance practices at every stage of sourcing and fulfillment. Beyond presenting dependable products, we also strive to present competitive, timely, and curated procurement options for the benefit of our customers. With this in mind, we encourage you to check out our inventory and get in touch with a representative to see how we can readily address your requirements.
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