Copper Alloy BrAZh9-4 Cast-Centrifugal
Finish state
Best for large bushings, wear rings and gear blanks — dense, porosity-free wall with the highest cast strength.
Values for the Cast-Centrifugal condition
Other BrAZh9-4 tempers and conditions
BrAZh9-4 is listed in 7 conditions; see the grade overview at BrAZh9-4.
Compare all 7 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Cast-SandDefault as-cast in sand mould (БрАЖ9-4Л, песчаная форма) | Standard general-purpose casting condition for housings, bushings and valve bodies where section sizes are large. | 180 | 450 | 15 | 110 HB | 13 % IACS |
permanent (metal) mould casting, кокильное литьё | Choose for thinner, denser castings needing higher strength and hardness than sand cast. | 200 | 500 | 12 | 120 HB | 13 % IACS |
soft annealed 700–750 °C, air cooled (мягкий, отожжённый) | Use when the part must be bent, straightened or further cold-worked, or to relieve casting/welding stresses. | 200 | 500 | 28 | 105 HB | 14 % IACS |
Cast-CentrifugalThis page centrifugally cast sleeve/bushing stock | Best for large bushings, wear rings and gear blanks — dense, porosity-free wall with the highest cast strength. | 220 | 550 | 12 | 130 HB | 13 % IACS |
hot-extruded / pressed bar, rod and tube (прессованный) | The usual stock form for shafts, bushings and worm-gear blanks machined from bar. | 250 | 550 | 20 | 130 HB | — |
Cold-drawn hard rod/wire | Pick when maximum strength, straightness and surface finish are needed on small-diameter bar or wire. | 400 | 650 | 8 | 170 HB | 12 % IACS |
Quenched and tempered | Highest hardness and wear/galling resistance for gear teeth, dies and heavily loaded bushings; ductility drops sharply. | 400 | 700 | 6 | 20 HRC | 11 % IACS |
What is BrAZh9-4 Cast-Centrifugal?
BrAZh9-4 Cast-Centrifugal is BrAZh9-4 supplied in the Cast-Centrifugal condition — best for large bushings, wear rings and gear blanks — dense, porosity-free wall with the highest cast strength. BrAZh9-4 Cast-Centrifugal has a yield strength of 220 MPa (31.9 ksi) and a tensile strength of 550 MPa (79.8 ksi) — weaker than 51% of copper alloy grades. Elongation at break is 12% and the elastic modulus is 110 GPa (16 Msi). BrAZh9-4 Cast-Centrifugal has a density of 7.6 g/cm³ (0.275 lb/in³), lighter than 93% of copper alloy grades. It melts at 1,040°C (1,904 °F). Cast-Sand is the default condition FabDigit quotes; Cast-Centrifugal is available on request or by drawing note.
Advantages
- Lightweight — 7.6 g/cm³ (0.275 lb/in³), better than 93% of copper alloy grades
- High service temperature — 300°C (572 °F), better than 85% of copper alloy grades
- Good corrosion resistance — 72/100, better than 84% of copper alloy grades
Limitations
- Low fracture toughness — 33 MPa·√m (30 ksi·√in), worse than 85% of copper alloy grades
BrAZh9-4 Cast-Centrifugal properties
Typical room-temperature values for BrAZh9-4 Cast-Centrifugal; 22 are specific to this condition. Other listed values are BrAZh9-4 reference data and may not represent this condition. Bars are the position among copper alloy grades.
Physical3
BrAZh9-4 Cast-Centrifugal has a density of 7.6 g/cm³ (0.275 lb/in³), lighter than 93% of copper alloy grades. It melts at 1,040°C (1,904 °F).
Mechanical16
BrAZh9-4 Cast-Centrifugal has a yield strength of 220 MPa (31.9 ksi) and a tensile strength of 550 MPa (79.8 ksi) — weaker than 51% of copper alloy grades. Elongation at break is 12% and the elastic modulus is 110 GPa (16 Msi).
Thermal6
BrAZh9-4 Cast-Centrifugal is rated for continuous service to 300°C (572 °F). It conducts heat at 59 W/m·K (34.1 BTU/hr·ft·°F), worse than 61% of copper alloy grades. Thermal expansion is 16.2 µm/m·K (9 µin/in·°F).
Electrical3
BrAZh9-4 Cast-Centrifugal conducts electricity at 13 % IACS, worse than 58% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is very good (72/100), better than 84% of copper alloy grades.
Sustainability4
Producing a kilogram of BrAZh9-4 Cast-Centrifugal takes about 62 MJ of energy and emits 3.9 kg of CO₂ — more than 76% of copper alloy grades. Typical recycled content is 45%.
Manufacturability8
BrAZh9-4 Cast-Centrifugal's machinability is fair (38/100, better than 55% of copper alloy grades); weldability fair (50/100); formability poor (28/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with BrAZh9-4 Cast-Centrifugal
Is BrAZh9-4 easy to machine?
Machines like a tough, gummy bronze — use sharp positive-rake carbide, 60–120 m/min, heavy feed and flood coolant; chips are stringy, so chipbreakers and rigid setups matter.
Can BrAZh9-4 be welded?
GTAW/GMAW with matching Cu-Al (ERCuAl-A2) filler, 150–250 °C preheat on heavy sections, DCEN/AC to break the alumina film; avoid oxyacetylene and interpass temperatures above ~350 °C.
Can BrAZh9-4 be formed, bent or molded?
Hot work 750–900 °C (extrusion, forging); cold bending is limited, so anneal at 700–750 °C between passes. In the foundry use bottom gating and generous filters to keep oxide skins out of the metal.
What surface finishes work on BrAZh9-4?
Not anodisable; it self-passivates to an olive-brown film. Polishes well, accepts tin, nickel or chrome plating after careful alumina removal, and is commonly left bare in seawater service.
BrAZh9-4 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| AlGOST 18175-78 / 493-79; C95200 narrows to 8.5–9.5 | 8 – 10 | 9 |
| Fegrain refiner, forms κ particles | 2 – 4 | 3 |
| Mnimpurity limit | ≤ 0.5 | — |
| Znimpurity limit | ≤ 1 | — |
| Siimpurity limit | ≤ 0.1 | — |
| Snimpurity limit | ≤ 0.1 | — |
| Pbimpurity limit | ≤ 0.03 | — |
| Pimpurity limit | ≤ 0.01 | — |
| Cu≈86–90 %, remainder; total impurities ≤1.7 % | balance | — |
BrAZh9-4 Cast-Centrifugal — frequently asked
What is BrAZh9-4 Cast-Centrifugal used for?
BrAZh9-4 Cast-Centrifugal is typically used for pump impellers, valve seats and bushings. In short: seawater-resistant cast bronze; stronger than tin bronzes; self-passivating alumina film.
What is the yield strength of BrAZh9-4 Cast-Centrifugal?
BrAZh9-4 Cast-Centrifugal has a typical yield strength of 220 MPa (31.9 ksi) and a tensile strength of 550 MPa (79.8 ksi) — weaker than 51% of copper alloy grades. Strength varies by condition: see the 7 listed tempers.
Is BrAZh9-4 Cast-Centrifugal easy to machine?
Not especially — machinability is rated fair (38/100, better than 55% of copper alloy grades). Machines like a tough, gummy bronze — use sharp positive-rake carbide, 60–120 m/min, heavy feed and flood coolant; chips are stringy, so chipbreakers and rigid setups matter.
Can BrAZh9-4 Cast-Centrifugal be welded?
With care — weldability is rated fair (50/100). GTAW/GMAW with matching Cu-Al (ERCuAl-A2) filler, 150–250 °C preheat on heavy sections, DCEN/AC to break the alumina film; avoid oxyacetylene and interpass temperatures above ~350 °C.
What surface finishes work on BrAZh9-4 Cast-Centrifugal?
Not anodisable; it self-passivates to an olive-brown film. Polishes well, accepts tin, nickel or chrome plating after careful alumina removal, and is commonly left bare in seawater service.
Can BrAZh9-4 Cast-Centrifugal be formed, bent or molded?
Hot work 750–900 °C (extrusion, forging); cold bending is limited, so anneal at 700–750 °C between passes. In the foundry use bottom gating and generous filters to keep oxide skins out of the metal.
What is the maximum service temperature of BrAZh9-4 Cast-Centrifugal?
BrAZh9-4 Cast-Centrifugal is rated for continuous use to about 300°C (572 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between BrAZh9-4 Cast-Sand and BrAZh9-4 Drawn-H?
Cast-Sand is the default condition — standard general-purpose casting condition for housings, bushings and valve bodies where section sizes are large. Drawn-H: pick when maximum strength, straightness and surface finish are needed on small-diameter bar or wire. Yield strength is 180 MPa in Cast-Sand versus 400 MPa in Drawn-H.
Sources
- GOST 18175-78 — Wrought aluminium bronzes (БрАЖ9-4) — Gosstandart (1978)
- GOST 493-79 — Cast tin-free bronzes (БрАЖ9-4Л) — Gosstandart (1979)
- ASTM B505/B505M, B271, B148 — copper-alloy castings (C95200) — ASTM International (2022)
- CDA alloy datasheet C95200 (9A aluminium bronze) — Copper Development Association (2023)
- ASM Handbook Vol. 2 — Properties of Copper and Copper Alloys — ASM International (1990)
- GB/T 1176 / GB/T 4423 — QAl9-4 cast and wrought aluminium bronze — SAC (2013)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.