1. 介绍
我们 C90300 is a widely used tin-bronze casting alloy that delivers a practical combination of good castability, 耐腐蚀性 (特别是在海洋环境中), bearing/wear behavior and satisfactory mechanical strength.
It is specified for bushings, 泵零件, 阀, gears and other components where service loading, sliding contact and corrosion resistance are primary drivers.
2. What is Bronze UNS C90300?
UNS C90300 is a cast tin 青铜 alloy in the UNS (统一编号系统) 铜合金家族.
It is formulated for foundry use and is widely specified where a balance of 可铸性, 耐腐蚀性 (particularly in marine and water-handling environments), good bearing/wear behavior and reasonable mechanical strength 是必须的.
In practice C90300 is chosen for components such as bushings, 袖子, pump and valve parts, small gears and marine fittings where sliding contact, embedability and resistance to seawater or wet corrosion are important.
Key features and metallurgical character
- 良好的铸造性. C90300 pours and fills molds predictably in sand, shell and investment processes, enabling reasonably thin sections and good surface detail when processed correctly.
- Tin-strengthened matrix. Tin acts as a substitutional alloying element in copper, raising hardness, wear resistance and strength relative to plain copper while preserving ductility sufficient for many bearing and structural uses.
- Bearing and tribological performance. 合金展品 conformability and embedability—it will accept small contaminant particles into the softer bronze matrix rather than score a harder mating shaft, making it suitable for plain bearings and bushings under boundary or mixed lubrication.
- Excellent wet-environment corrosion resistance. Tin bronzes resist general corrosion and perform well in seawater and many industrial aqueous environments; they are less prone to dezincification or rapid localized attack than many brasses.
- Not precipitation-hardening. Mechanical properties are established primarily by composition and solidification/microstructure; C90300 is not normally subject to strengthening by solution/aging treatments.
Stress-relief or annealing operations are used mainly for dimensional stability or ductility adjustments. - 适度的可加工性. Tin improves chip formation and machinability relative to many high-strength copper alloys; carbide tooling and standard bronze machining practices are appropriate for production work.
3. 合金特性和典型化学成分
Values are presented as typical weight-percent ranges used for design and procurement; always confirm exact limits with the foundry’s mill/certified analysis for any critical application.
| 物品 | 典型成分 (wt％) | 功能 / 影响 |
| UNS designation | C90300 | Unified Numbering System identity for this cast tin-bronze. |
| 铜 (铜) | 平衡 (~86.0 – 89.0%) | 碱金属; provides matrix, thermal/electrical properties and ductility. |
| 锡 (sn) | 7.5 - 9.0% | Principal strengthening and wear/corrosion-resistant element in the alloy. |
| 锌 (Zn) | 3.0 - 5.0% | 提高流动性, castability and deoxidation of the melt. |
| 镍 (在) | 0 - 1.0% (typ。) | 选修的; can improve corrosion resistance, strength and toughness. |
| 铁 (铁) | ≤ ~0.5% (typ。) | Controlled impurity or deliberate addition; affects strength and wear. |
带领 (pb) |
≤ ~0.2–0.25% (痕迹) | May appear at trace levels in some castings; small amounts aid machinability but are not a defining element. |
| 硅 (和) | ≤ ~0.5% (痕迹) | Deoxidation/fluidity influence; normally controlled to low levels. |
| 磷 (p) | ≤ ~0.03% (痕迹) | Deoxidizer/degasser residue; kept very low to avoid embrittlement. |
| 硫 (s) | ≤ ~0.02% (痕迹) | 杂质; low levels tolerated; excessive S is detrimental. |
| 铝 / 锰 / other | Each typically ≤ ~0.1–0.3% | Minor micro-alloying or tramp elements controlled to specification. |
4. Physical and mechanical properties
Below are representative as-cast values for C90300 drawn from typical supplier and material-data references.
Actual properties vary with casting process, 截面厚度, gating strategy and melting practice — always validate with cast coupons from your foundry.
物理特性
| 性能特性 | 典型值 |
| 密度 | ≈ 8.7–8.9 g/cm³ (≈ 0.318 lb/in³). |
| 实心 / 液体 | ~854 °C (实心) - ~1000 °C (液体) (guide to safe pouring and superheat). |
| 导热率 | ~70–75 W/m·K (depends on Sn/Zn content). |
| 电导率 | ~10–12 % IACS (low compared with pure copper). |
| 热膨胀系数 | ≈ 17 ×10⁻⁶ /°C (room to moderate temps). |
机械性能 (typical as-cast)
| 性能特性 | 典型范围 / 价值 |
| 抗拉强度 (UTS) | ~300–320 MPa (≈ 44–46 ksi) |
| 屈服 (0.5% 抵消) | ~145–152 MPa (≈ 21–22 ksi) |
| 伸长 (在 50 毫米) | ~18–30% depending on section and process |
| 布氏硬度 (BNN) | 〜70 hb (铸态典型值) |
| 弹性模量 | ~110–125 GPa |
5. 铸造行为和铸造实践
Suitable casting processes
C90300 is adaptable to the major casting methods used for bronzes:
- 沙子铸造 — economical for large or heavy sections.
- 熔模铸造 (迷失的蜡像) — best surface finish and dimensional accuracy for thinner, 详细的零件.
- 外壳成型 and permanent-mold casting — intermediate options offering improved surface finish and tolerance.
- Continuous and centrifugal casting are also used for bars, rings and certain shapes.
Critical casting parameters
- 浇注温度 / 过热: respect the alloy liquidus and avoid excessive superheat;
Concast data indicate liquidus near ~1000 °C and solidus near ~854 °C — control within a narrow window to balance fluidity and avoid oxidation/dross. - 融化清洁度: degassing and filtration are essential; tin bronzes are sensitive to hydrogen porosity and oxide inclusions — ceramic filters and rotary degassers reduce risks.
- 门控 & 进食: design feeders to supply shrinkage in heavy sections and use gradual sectional transitions to avoid hot-spots and hot-tears.
模拟 (fill/solidification) is recommended for complex geometries. - 固化控制: directional solidification with chills or chills/risers helps reduce shrinkage defects and refines microstructure in thicker portions.
铸造热处理
C90300 is not a precipitation-hardening alloy; it does not respond to solution-age heat treatments to raise strength.
Typical thermal steps are stress-relief anneals (to remove casting stresses and improve machinability) or moderate anneals to improve ductility where required.
Practical foundry practice relies on casting control — not heat treatment — for most mechanical property objectives.
6. 可加工性, 加入 & 精加工
可加工性
- 适度的可加工性 — tin content enhances chip formation and machinability relative to many high-strength copper alloys;
common machinability rating values place C90300 in a practical class for routine turning, milling and drilling with carbide tooling. - Recommended practice: use rigid fixturing, 碳化物工具 (coated grades for production), conservative feeds to avoid built-up edge, and light finishing passes for critical surfaces.
Sulfur and lead contents in other alloys (not C90300 lead-free variants) can alter chip control — verify composition before selecting cutting parameters.
加入
- 悬挂 is the preferred joining method for bronze castings when required (filler metals and flux selected for bronze compatibility).
- 焊接 is generally avoided for large castings because bronze tends to suffer from thermal cracking and property changes; localized welding can be used with specialist procedures and post-weld stress relief where unavoidable.
表面饰面
- 抛光, 电镀 (在, Ag), lacquering or patination are commonly applied depending on functional or aesthetic requirements.
For bearing surfaces, honing or lapping produces the required surface texture for lubricant film formation.
(Select finishing and joining processes in consultation with the foundry to avoid galvanic compatibility issues and finish adhesion problems.)
7. 腐蚀, wear and tribological performance
- 耐腐蚀性: Tin bronzes such as C90300 exhibit excellent resistance in fresh and seawater environments and are commonly used for marine hardware and pump components.
Their tin content promotes a stable surface film and reduces susceptibility to certain localized corrosion mechanisms. - Tribology and bearing behavior: C90300 is valued for good conformability and embedability — under mixed or boundary lubrication it tends to accept small hard particles into the softer bronze matrix rather than scoring the harder shaft.
This makes it a favored material for bushings, plain bearings and sleeves running against hardened steel. Proper lubrication and surface finish are still necessary for long service life.
设计说明: for high-load rotating bearings consider tested bearing geometry, lubrication regime and possible use of lined or composite bearings if duty exceeds bronze’s capability.
8. Typical applications of UNS C90300 alloy
Common service areas where UNS C90300 is specified:
- 衬套, sleeves and plain bearings (hydraulic pumps, 变速箱).
- Pump and valve components (叶轮, 阀体, 座位) — especially in marine and water-handling equipment.
- 齿轮, worm wheels and small structural castings where castability and wear resistance are needed.
- 海军陆战队 fittings and propeller components where seawater corrosion resistance is required.
- Decorative castings and architectural elements where patina and aesthetics matter.
| Comparison factor | C90300 (Tin bronze) | C51000 (磷青铜) | C95400 (Aluminum bronze) | 铅铜 (例如。, C93200, 一般的) |
| 典型成分 (wt％) | Cu ≈ 86–89; Sn ≈ 7.5–9; Zn ≈ 3–5; minor Fe/Ni | Cu ≈ 90–95; Sn ≈ 5–10; P ≈ 0.01–0.35 (痕迹) | Cu ≈ 78–88; Al ≈ 5–11; Fe/Ni/C (次要的) | 铜 + Sn base with pb additions ~1–4% (各种), small Zn/Sn |
| Primary strengthening mechanism | 实心解决方案 & tin-rich phases from casting | 实心解决方案 + phosphide dispersion (p) — good spring/fatigue | 实心解决方案 + ordered phases; high strength via Al content | 实心解决方案; Pb acts as free-machining/soft phase for chip control |
| Typical as-cast UTS (MPA) | ~300–320 MPa | ~350–500 MPa (varies with alloy & 治疗) | ~400–650 MPa (更高的强度) | ~220–350 MPa (depends on Pb, Sn content) |
Typical hardness (HB) |
~70–140 HB (过程依赖) | ~80–160 HB | ~120–220 HB (更高) | ~60–120 HB (softer due to Pb) |
| 穿 & bearing performance | Good conformability & embedability; widely used for bushings | Excellent fatigue and spring performance; good bearing alloys available | Excellent wear and high-load bearing capability | Good lubricity/embeddability; excellent machinability for bearing inserts |
| 耐腐蚀性 (海水 / wet env.) | 非常好 (marine service common) | 好到非常好 (depends on Sn) | Very good to excellent (aluminum bronzes outstanding in seawater) | 一般; leaded alloys can corrode in some environments; not preferred for seawater |
可铸性 (foundry behavior) |
Very good — sand, 壳, 投资 | 良好; available as cast or wrought; phosphor bronze often wrought | Good to fair — higher pouring temp, picky on melt control | 出色的铸造性; widely used for economical cast bearings/parts |
| 可加工性 | Moderate — improved by Sn for chip control | 良好 (phosphor bronzes can be challenging if hard) | Moderate to difficult — hard alloys wear tools | 出色的 (lead dramatically improves free-cutting behavior) |
| Heat treatability / 硬化 | Not precipitation-hardenable; anneal/stress relief only | Some variants respond to cold work; not classic age-hardening | Some alloys can be heat treated for strength (solution/aging) | Not age-hardening; properties controlled by composition and working |
典型的应用 |
衬套, 泵零件, 阀, 海洋配件, 蜗轮 | 轴承, 弹簧, 电连接器, wear components | 重型轴承, 海洋螺旋桨, high-load components, 齿轮 | Economical bushings, 配件, low-cost machined parts, 大批量组件 |
| 相对成本 | Moderate — tin is a premium element | 中高 (phosphor and high Sn increase cost) | 更高 (Albronzes and alloying raise cost) | 降低 (leaded alloys are economical) |
| 关键权衡 / selection note | Balanced choice for wear + 腐蚀 + 可铸性 | Choose when fatigue / spring performance or electrical properties matter | Choose for highest strength & severe wear / 气阻 | Choose where machining cost dominates and corrosive service is not critical; restricted in potable/water use |
10. 结论
UNS C90300 tin bronze is a 时间测试, high-value cast copper alloy that excels in balancing mechanical strength, 戴阻力, corrosion durability, 和可铸性.
Its carefully engineered chemical composition and uniform microstructure deliver consistent performance in moderate-load, low-to-medium speed service environments, making it indispensable in marine, 流体处理, mechanical power transmission, and general engineering sectors.
常见问题解答
What is the typical tin content in C90300?
Typical tin is ~7.5–9.0 wt% with copper as the balance; zinc is commonly present at ~3–5 wt%. Always check the mill certificate for the lot you receive.
Can C90300 be heat treated to increase strength?
No — C90300 is not a precipitation-hardening alloy.
Strength and ductility are primarily controlled through composition, section size and solidification rate; stress-relief anneals are used for dimensional stability.
Is UNS C90300 suitable for seawater service?
Yes — tin bronzes such as C90300 are routinely used in marine environments and pump components because of good seawater corrosion resistance and anti-fouling behavior relative to many steels.
What casting process should I specify?
使用 投资铸造 for thin, detailed parts and tight tolerances; sand or shell casting for larger or economy parts.
Specify desired surface finish, tolerance band and NDT requirements up front.
