Aluminum Bronze Plates
Aluminum Bronze Plates
Self-lubricating bronze bearings are engineered for applications where external lubrication is impractical. Solid lubricants are compressed and molded directly into the bearing to guarantee a maintenance-free product. No additional lubrication is necessary.
Aluminum Bronze Plates for Wear, Slide and Liner Applications
Aluminum bronze plates are copper-based alloys containing roughly 5–12% aluminium, supplied as sawn flat stock or finish-machined components for sliding and wear duties. The aluminium forms a thin, adherent oxide film on the surface. When the film is scraped away it reforms, which is why these alloys hold up in seawater, mine water and chemically aggressive service where plain carbon steel does not.
This page covers the grades we stock, how their mechanical and corrosion behaviour compares, when to specify graphite-plugged or grooved plate instead of plain plate, and what information we need to quote a custom size.
What is an aluminum bronze plate
Aluminum bronze is a family of copper alloys in which aluminium, not tin, is the principal alloying element. Most engineering grades sit between 9% and 11.5% aluminium, with iron, nickel and manganese added to raise strength, refine the grain and improve corrosion behaviour. A plate is simply this alloy produced as flat stock, then used as a wear face, slide way, liner or structural bearing surface.
Three supply forms are common:
- Sawn plate — cut from continuously cast or sand cast stock, used where the mating surface can be finish-machined on site.
- Machined plate — milled or ground to a specified flatness and thickness, usually with drilled and counterbored holes.
- Engineered plate — machined plate with graphite plugs embedded in the sliding face, or with grease grooves cut to a pattern.
Plates differ from aluminum bronze bushings in one practical way: a bushing constrains a shaft all round, while a plate carries load on one flat face and can usually be replaced without dismantling the shaft. That makes plate the usual choice for large, slow-moving or oscillating contacts.
Grades we supply
Grade selection is mostly a trade between hardness and toughness. Higher aluminium content raises hardness and wear resistance but reduces ductility. The figures below are typical ranges for the cast condition; heat treatment moves them, and a mill certificate always governs.
| UNS | Typical composition | Tensile strength | Yield strength | Hardness (HB) | Elongation | Typical use |
|---|---|---|---|---|---|---|
| C95400 | Cu-11Al-4Fe-Ni | 586 MPa (85 ksi) | 240 MPa (35 ksi) | 170–195 | 12–18% | General wear plates, mill slippers, gears, valve guides |
| C95500 | Cu-11Al-4Ni-3Fe | 690 MPa (100 ksi) | 310 MPa (45 ksi) | 190–230 | 6–12% | Heavy-load slide plates, valve seats, marine hardware |
| C95900 | Cu-12.5Al-Fe | ≥ 655 MPa | ≥ 515 MPa | 260–290 | about 1–2% | Abrasive wear plates, gibs, press liners |
| C63000 | Cu-10Al-5Ni-3Fe (wrought) | 640–760 MPa | 280–345 MPa | 185–210 | 12–20% | Where higher toughness or a wrought structure is required |
C95400 is the usual starting point and the one most often stocked. C95500 adds nickel and is the choice when the plate also carries shock or structural load. C95900 is markedly harder and is selected for abrasive sliding where impact is low — its elongation is low, so it is not the right answer where the plate can be struck. C63000 is a wrought nickel aluminum bronze used when the section is thin or when the specification calls for a wrought rather than cast structure.
Aluminum Bronze Plates with graphite
Mechanical and physical properties
| Property | Typical value | Why it matters for plate design |
|---|---|---|
| Density | 7.4–7.6 g/cm³ | Weight of large plates; handling and support design |
| Elastic modulus | 110–120 GPa | Deflection under load; lower than steel |
| Thermal conductivity | 45–59 W/(m·K) | Carries frictional heat away from the contact face |
| Coefficient of thermal expansion | 16–17 × 10-6/K | Expansion gap needed when plate is bolted to a steel frame |
| Continuous service temperature | about 300 °C (about 400 °C with graphite plugs) | Above this the alloy loses strength; confirm against your duty cycle |
| Magnetic permeability | Low; non-sparking | Suitable for explosive atmospheres and near magnetic equipment |
The thermal expansion figure is the one most often overlooked. An aluminum bronze plate expands roughly 30% more than the steel frame it is bolted to, so long plates need slotted holes or a defined expansion gap. Ignoring this is a common cause of plate bowing after installation.
Corrosion and wear behaviour
The aluminium oxide film gives these alloys their corrosion resistance, and it is self-healing under flowing conditions. In practice that means:
- Seawater and brackish water — aluminum bronzes are established materials for marine service, and resist biofouling better than many copper alloys.
- Erosion and cavitation — the combination of a hard surface and a tough substrate handles impingement and cavitation better than tin bronze.
- Galling against steel — aluminum bronze has good resistance to adhesive wear when running dry or poorly lubricated against steel, which is why it is used for gibs and slide ways.
Three limitations are worth stating plainly, because they decide where the material should not be used:
- Ammonia and ammonium compounds — aluminum bronzes are susceptible to stress corrosion cracking in ammoniacal environments. If the service environment contains ammonia, ask for a different alloy.
- Dealuminification — selective leaching of aluminium can occur under specific conditions, typically in acidic media or stagnant high-temperature service. Continuous or regularly flushed service avoids most of it.
- Galvanic coupling — aluminum bronze is more noble than carbon steel. When the two are in electrical contact in an electrolyte, the steel corrodes preferentially. Insulate the joint or plan for the steel to be the sacrificial item.
Self-lubricating options
A plain plate needs external lubrication. When the location is inaccessible, when grease would contaminate the product, or when the duty cycle is too slow to build a lubricant film, the plate can be engineered to carry its own lubricant.
Graphite-plugged plates
Solid graphite plugs are embedded in the sliding face in a pattern, typically covering 20–30% of the contact area. As the surface wears, graphite transfers to the mating surface and forms a solid lubricating film, so the plate runs without grease. This suits low-speed, high-load or oscillating motion, and it removes the maintenance task entirely.
See C62700 aluminum bronze slide plates with graphite plugs for the plug layout options.
Grease groove patterns
Where relubrication is possible, grooves cut into the face distribute grease across the contact. Common patterns include straight, figure-eight, double-loop and radial. Grooves reduce the bearing area, so they are sized against the contact pressure rather than added by default.
Choosing between them
| Condition | Recommended form |
|---|---|
| No access for relubrication | Graphite-plugged plate |
| Product must stay grease-free | Graphite-plugged plate |
| Slow or oscillating motion | Graphite-plugged plate |
| Regular relubrication is possible | Grooved plain plate |
| Very high contact pressure with ample grease supply | Grooved plain plate |
| Continuous rotation at speed | Grooved plain plate; graphite plugs suit sliding better than rotation |
Aluminum bronze vs tin bronze vs manganese bronze
| Criterion | Aluminum bronze | Tin bronze | Manganese bronze |
|---|---|---|---|
| Strength | High | Moderate | High |
| Corrosion in seawater | Good, self-healing oxide film | Good | Moderate; watch dezincification |
| Wear under high load | Good | Moderate | Good |
| Impact toughness | Moderate to good | Good | Good |
| Machinability | Moderate | Good | Moderate to good |
| Typical reason to choose it | Corrosive or abrasive service with high load | General-purpose bearing duty at moderate load | High static load and shock, see manganese bronze plate |
The short version: aluminum bronze earns its place where load and corrosion arrive together. If the environment is benign and the load is moderate, tin bronze usually costs less and machines faster.
Typical applications
- Rolling mills and steel plants — slippers, slide plates, housing liners, gibs.
- Marine — rudder and stern tube wear surfaces, deck equipment slides, pipe support sliding plates.
- Mining and mineral processing — crusher and conveyor wear liners, screen side plates.
- Hydropower — gate slides, turbine wear rings, trash rack components.
- Press and die work — die set guide plates, cam dwell plates, bolster wear strips.
- Injection molding — tie bar and ejector plate wear surfaces.
- Bridges and structures — bearing and expansion joint sliding plates.
Related: bronze wear plates and bronze liner plates.
Sizes, tolerances and machining
Plate is normally supplied in the 5 mm to 100 mm thickness range, sawn or finish-machined. Width and length follow the casting and sawing capability; non-standard sizes are produced from drawing rather than cut from a stock sheet, because the alloy is cast rather than rolled in these sections.
Machining notes that affect lead time and cost:
- Aluminum bronze work hardens. Sharp tools and consistent feed rates matter more than on free-machining brass.
- Cast plate carries residual stress. Rough machine, stress relieve, then finish machine if flatness is critical.
- Holes, counterbores, tapped holes and custom profiles are produced to drawing.
- Waterjet cutting is used for complex outlines where milling would be uneconomic.
How to specify an aluminum bronze plate
Send as many of these as you have. The first four are usually enough for a budget quote:
- Alloy grade, or the service conditions if you are unsure which grade applies.
- Length, width and thickness, plus the tolerance that matters.
- Lubrication arrangement: plain, grooved, or graphite-plugged.
- Quantity, including whether this is a one-off or a repeat item.
- Mating material and its hardness.
- Load, speed and whether motion is continuous, oscillating or intermittent.
- Operating temperature range and the environment (seawater, mine water, chemicals, dust).
- A drawing or a sample of the existing part.
Frequently asked questions
Is aluminum bronze plate suitable for continuous seawater immersion?
Yes, it is a standard material for marine service, and the surface oxide film reforms under flowing conditions. Tell us if the plate will sit stagnant for long periods or if ammonia is present in the environment, since those conditions change the recommendation.
Does a graphite-plugged plate still need grease?
No. The graphite plugs supply the lubrication. Grease is not required and is generally not applied, as it tends to collect abrasive dust.
Can aluminum bronze be welded?
It can be welded with matching filler metal, with preheat and controlled interpass temperature. Post-weld stress relief is normally required on restrained sections. For most wear plate applications, mechanical fixing is simpler and avoids the metallurgical risk.
Which wears first, the plate or the steel it runs against?
Aluminum bronze is normally harder than the structural steel it is paired with, so the steel counterpart tends to wear first. This is deliberate: the plate is the replaceable item. If your design makes the steel component the expensive one, tell us and we will look at hardness matching.
What is the temperature limit?
Design for about 300 °C continuous service for plain plate. Graphite-plugged plate can run higher, around 400 °C, because the graphite itself is unaffected. Confirm against your actual duty cycle before finalising.
Get a quote
We supply aluminum bronze plate sawn, machined, grooved or graphite-plugged, to drawing or to sample. Send the dimensions, grade and quantity and we will come back with a recommendation and a price. Drawings in DXF, DWG or PDF are all workable.
Email: una@viiplus.com
