1. 導入
UNS C95500 is one of the most important nickel aluminum bronzes in modern engineering because it combines high strength, 優れた耐食性, good wear performance, and strong service reliability in severe environments.
It is widely used in marine hardware, バルブコンポーネント, ベアリング, ブッシング, 歯車, 航空機部品, and other applications where ordinary copper alloys are no longer sufficient.
The alloy is also notable for retaining useful strength at elevated temperatures and for performing well in seawater and other aggressive media.
What makes C95500 especially interesting is that it is not a “single-purpose” alloy.
It is a systems alloy: its value appears differently depending on whether the engineer is optimizing for corrosion, 着る, 耐圧性, structural loading, or temperature stability.
2. What Is UNS C95500 Nickel Aluminum Bronze?
UNS C95500 is a cast nickel aluminum ブロンズ in the copper–aluminum–iron–nickel family.
It is specifically formulated for demanding service where 強さ, 耐摩耗性, 耐食性, そして靭性 must be balanced in one alloy rather than optimized separately.
実際に, this places C95500 in the group of high-performance structural bronzes used for marine hardware, バルブコンポーネント, ブッシング, 歯車, and other severe-service parts.
Unlike free-machining brasses or general-purpose bronzes, C95500 is not chosen for convenience.
It is selected because its metallurgical design supports load-bearing performance in aggressive environments, especially where seawater, sliding wear, and long service life are all part of the design brief.
Alloy Identity
C95500 belongs to the C95000–C95999 family of copper-aluminum-iron and copper-aluminum-iron-nickel alloys.
That family classification matters because it distinguishes nickel aluminum bronzes from ordinary brasses and from tin bronzes:
the alloy system is built around aluminum as the principal strengthening element, with iron and nickel added to improve strength, structure control, and service performance.
In specification terms, C95500 is a cast aluminum bronze rather than a wrought alloy.
That means its typical engineering role is to deliver complex shape plus high performance in the as-cast or heat-treated condition, instead of relying on rolling or drawing to achieve properties.
化学組成
Chemical composition according to ASTM B505/B505M-23
| 要素 | C95500 Composition |
| 銅 | 78.0% 分. |
| 鉄 | 3.0–5.0％ |
| で | 3.0–5.5% |
| アル | 10.0–11.5% |
| ん | まで 3.5% |
| Named-elements total | 99.5% 分. |
3. Physical Properties of UNS C95500
| 物理的な / Functional Property | Metric Unit | Imperial Unit |
| 密度 | 7.53 g/cm3 | 0.272 ポンド/インチ3 |
| Specific gravity | 7.53 | 7.53 |
| 電気伝導率 | 8% IACS | 8% IACS |
| 熱伝導率 | 41.9 W/m・K | 24.2 Btu/sq ft/hr/°F |
| 熱膨張係数 | 15.5 ×10⁻⁶ /°C | 9 × 10⁻⁶ /°F |
| Specific heat capacity | 419 J/kg・K | 0.1 Btu/lb·°F |
| 弾性率 | 110 GPa | 16,000 クシ |
| ポアソン比 | 0.32 | 0.32 |
| 透磁率, as-cast | 1.32 | 1.32 |
| 透磁率, TQ50 temper | 1.2 | 1.2 |
| 融点, 液体 | 1054℃ | 1930°F |
| 融点, ソリッド | 1038℃ | 1900°F |
4. Mechanical Properties of UNS C95500
UNS C95500 is a high-strength nickel aluminum bronze whose mechanical performance is usually evaluated in two published conditions: the standard continuous-cast C95500 condition and the heat-treated C95500HT 状態.
The values below are representative room-temperature properties reported for ASTM B505/B505M-23 product forms.
Mechanical Properties of Continuous-Cast C95500
| 財産 | Metric Unit | Imperial Unit |
| 抗張力, 分. | 655 MPa | 95 クシ |
| Yield strength at 0.5% extension, 分. | 290 MPa | 42 クシ |
| Elongation in 2 で. (50 mm), 分. | 10% | 10% |
| ブリネル硬さ, 典型的な | 208 HBW | 208 HBW |
Mechanical Properties of Heat-Treated C95500HT
| 財産 | Metric Unit | Imperial Unit |
| 抗張力, 分. | 758 MPa | 110 クシ |
| Yield strength at 0.5% extension, 分. | 427 MPa | 62 クシ |
| Elongation in 2 で. (50 mm), 分. | 8% | 8% |
| ブリネル硬さ, 典型的な | 228 HBW | 228 HBW |
5. 耐食性
The corrosion story is one of the main reasons C95500 is so widely used. The alloy is repeatedly identified as having 優れた耐食性, including in 海水 海洋環境と.
It is also used for equipment handling seawater, sour mine waters, nonoxidizing acids, 産業プロセス流体, sewage-treatment applications, および船舶用ハードウェア.
The reason this matters is not simply “it does not rust.” Rather, C95500 offers an unusually valuable combination: corrosion resistance plus wear resistance plus strength.
In seawater, many materials fail either by general corrosion, キャビテーション, 浸食, or galling. C95500 is attractive because it addresses several of those failure modes at once,
which is why it appears in pump and valve components, ブッシング, シャフト, propeller-related service, and heavily loaded marine hardware.
This multi-mechanism resistance is the core of the alloy’s reputation.
In demanding service, the most valuable materials are not those that excel at one isolated property, but those that remain stable across several failure mechanisms. C95500 is a textbook example of that principle.
6. Manufacturing Perspective
鋳造: A Strong Alloy, But Not a Forgiving One
UNS C95500 is fundamentally a casting alloy, and its process behavior reflects that identity.
Published casting data describe it as having low casting yield, high drossing tendency, medium fluidity, medium gassing tendency, and high solidification shrinkage.
That combination tells a very clear engineering story: C95500 can produce high-performance castings, but it demands disciplined melt practice, sound gating and risering design, and careful control of oxidation and feeding.
C95500 is highly versatile in casting practice, but it is not forgiving.
It performs well across 砂, シェル, セラミック, 投資, 永久型, 連続, and centrifugal casting, yet every one of those routes demands careful control of feeding, oxide management, and solidification behavior.
Its short freezing range supports sound castings, but only when the foundry actively prevents drossing, 収縮欠陥, and gas-related issues.
That is why C95500 is considered a premium casting bronze rather than an easy one.
機械加工: Fully Machinable, But Not Free-Cutting
C95500 is machinable, but it is not a free-machining copper alloy.
Its published machinability rating is 50, which places it in the moderate-machinability category rather than the easy-cutting class.
The alloy tends to produce curled swarf, and the published engineering guidance warns that this can jam tooling and create surface imperfections through partial welding and tearing, particularly during bore machining.
そのため, dry cutting, chip control, and tooling strategy matter much more than they would in a free-cutting brass.
A useful processing nuance is that when heavy machining has already been performed, ある low-temperature stress relief around 350°C for at least one hour is recommended before final machining.
This is not mainly about making the alloy easier to cut; it is about reducing the risk of residual-stress-driven distortion and improving final dimensional stability.
言い換えると, C95500 can be machined efficiently, but it should be approached as a structural bronze that requires process discipline, not as a soft shop brass.
溶接: Possible in Specific Methods, But Not Universally Easy
Welding behavior in nickel aluminum bronze is strongly influenced by the protective aluminum-rich oxide film that naturally forms on the surface.
Because of that oxide layer, はんだ付け, ろう付け, and oxy-acetylene welding are generally not recommended as primary joining routes for these alloys.
The more appropriate welding processes identified in the engineering guide are TIG/GTAW, MIG/GMAW, MMA, electron beam welding, and friction welding.
Published fabrication data for C95500 also classify oxyacetylene welding as not recommended, その間 gas shielded arc welding そして coated metal arc welding are listed as suitable.
That distinction is important: C95500 is not a “weld-anywhere” alloy, but it is also not unweldable.
It can be joined successfully when the process is chosen with the oxide behavior, thermal input, and joint design in mind.
重要な部品については, welding procedure qualification and proper control of heat affected zones are essential because the alloy’s property balance is tied closely to its microstructure.
熱処理: A Major Lever for Performance
Heat treatment is one of the most important reasons C95500 is so widely used in demanding service.
The alloy can be processed in a quench-and-temper cycle that increases proof strength, 究極の引張強度, 衝撃強度, そして硬さ, while only slightly improving ductility.
For cast CuAl10Fe5Ni5-type nickel aluminum bronze, the published guide describes heating to 900–950°C, holding for about one hour, 水の消光, and then tempering at 600–650°C for approximately two hours.
That sequence raises strength significantly while preserving useful toughness.
The same guidance also notes an important practical limitation: complicated shapes can distort during the heating and quenching cycle, so part geometry, furnace capacity, and section thickness must all be considered before heat treatment is selected.
言い換えると, heat treatment is a powerful performance tool, but it is not free. It improves the alloy’s mechanical envelope only when the component design can tolerate the thermal cycle.
7. Advantages and Disadvantages of UNS C95500
Major Advantages
High strength with useful ductility.
Excellent resistance to seawater and aggressive media.
Strong wear and anti-galling performance.
Good elevated-temperature capability.
非浸漬および非磁性
Main Disadvantages
High Initial Cost
Machining is possible, but not easy.
Casting is technically demanding.
Welding is process-sensitive.
Electrical conductivity is low.
8. Applications of UNS C95500
海洋 and Offshore Hardware
C95500 is one of the most established materials for marine service because it combines seawater corrosion resistance, 強さ, そして耐摩耗性.
It is used in seawater piping and valve systems, 船舶用ハードウェア, propeller-related components, hatches, カップリング, シール, and other shipboard equipment.
The alloy family’s suitability for seawater handling is a major reason for its long-standing reputation in naval and marine engineering.
バルブ, ポンプ, and Flow-Control Components
The alloy is widely used for バルブ本体, バルブ 席, valve guides, バルブコンポーネント, pump fluid ends, glands, stuffing box nuts, and sealing flanges.
These applications benefit from its combination of corrosion resistance, 耐摩耗性, そして機械的強度, especially where water, プロセス流体, or mildly aggressive chemicals are present.
ベアリング, ブシュ, and Wear Parts
C95500 is frequently selected for ベアリング, ブッシング, プレートを着用してください, piston guides, そして機械部品 because it performs well under sliding contact and heavy loading.
Its wear resistance and toughness make it suitable where surface damage, かじりつく, or abrasive wear are concerns.
Gears and Power-Transmission Parts
The alloy is used in 歯車, worms, ウォームホイール, and related transmission components.
These parts require a material that can tolerate contact stress, maintain dimensional stability, and resist wear over long service intervals. C95500’s mechanical balance makes it a practical choice for such duty.
Industrial Process and Harsh-Service Equipment
The alloy is used in pickling equipment, sewage treatment applications, hot mill guides, and industrial hardware.
These uses reflect the alloy’s ability to survive corrosive media, mechanical loading, and repeated service cycling.
産業環境で, that combination can reduce maintenance intervals and improve reliability.
Electrical and Specialty Hardware
Although C95500 is not an electrical-conductivity alloy, it still appears in some electrical hardware and specialty components where structural reliability, 耐食性, and wear behavior are more important than conductivity.
It is also used in piano keys and musical instruments, where the alloy’s mechanical stability and manufacturability are useful.
9. 結論
UNS C95500 nickel aluminum bronze is a high-value engineering alloy because it combines properties that are often difficult to obtain together:
高強度, 優れた耐食性, strong wear resistance, 良好な靭性, and serviceability across a wide temperature range.
Its chemistry is carefully tuned, its casting behavior is demanding but manageable, and its heat-treatment response gives designers an extra performance lever when required.
実務的には, C95500 is best understood as a severe-service alloy.
It is most compelling where failure modes are mixed and unforgiving—seawater, moving load, 滑り接触, pressure duty, and long-life mechanical service.
That is why it remains one of the most respected nickel aluminum bronzes in engineering practice.
よくある質問
Is C95500 a casting alloy or a wrought alloy?
C95500 is primarily used as a 鋳造合金, with published references covering continuous cast, 砂鋳造, centrifugal cast, and precision cast forms.
Is C95500 good in seawater?
はい. It is repeatedly identified as having 優れた耐食性, 含む salt-water resistance, which is one of the main reasons it is used in marine hardware and valve systems.
Can C95500 be heat treated?
はい. The published engineering guide shows both as-cast and heat-treated performance for C95500, with heat treatment increasing strength further.
Is C95500 easy to machine?
It is machinable, but not free-machining. Its machinability rating is 50, so it is a moderate-machinability alloy rather than an easy-cutting one.
What is the main advantage of C95500 over ordinary bronzes?
Its main advantage is the combination of 高強度, 優れた耐食性, そして耐摩耗性, especially in harsh marine or industrial environments.
