Monel Vs Phosphor Bronze

Monel vs Phosphor Bronze

While monel is an alloy, whose major constituent is nickel, the secondary component is copper. Phosphor bronze on the other hand is an alloy, whose primary constituent element is copper. The chemistry of monel includes two metals i.e. nickel and copper, unlike phosphor bronze, whose chemistry also includes a metalloid. Both Phosphor bronze as well as Monel are available in various forms. The availability of phosphor bronze is typical in the form of nonferrous spring alloys. Though this alloy is also available as free-machining phosphor bronze as well as bearing bronze. Some of the more common monel alloys include - Monel 400, Monel 401, Monel 404, Monel 405, Monel 450, Monel K-500, Monel R-405 as well as Monel 502. Though the elemental composition remains the same, it is the level of the elements included that sets one grade apart from the other.

Monel and phosphor bronze price difference

Copper, like nickel, is a commodity metal. Though the price of nickel is high, the cost of copper is traded lower. Since the chemistry of monel contains more than 52% nickel, its cost is much higher than phosphor bronze. Phosphor bronze has a higher content of copper, with no inclusion or nickel, thereby effectively lowering its cost. The cost price of nickel and copper is dependent on the commodities market. Any fluctuations in the price of either metal will be reflected in the upcharge of the alloys.

Monel and phosphor bronze applications

Phosphor bronze alloys are distinguished for their properties including high strength, low coefficient of friction, good toughness, and fine grain. The inclusion of phosphorus in the alloy reduces the viscosity of the molten alloy. Hence, manufacturers find it easier and cleaner to cast. When alloyed with tin, increases there is an increase in the materials wear resistance, stiffness,  resistance to corrosion, and strength. One of the more conventional alloys has a composition of 94.8% copper, 5% tin with about 0.2% phosphorus. This composition makes the alloy well suited to cryogenics while imparting properties such as fair electrical conductivity and low thermal conductivity. A combination of these properties permits the making of electrical connections to machines at ultra low temperatures without the use of excessive heat.

Monel alloys exhibit resistance to corrosion from acids, which is why it is a typical addition in applications that have highly corrosive conditions. Some monel alloys are able to withstand a fire in pure oxygen, which is possible due to the significant content of nickel in its alloy. Similar to phosphor bronze, monel demonstrates excellent mechanical properties at subzero or cryogenic temperatures. At such temperatures, there is an increase in the Strength and hardness properties. Unlike some conventional alloys that undergo a ductile-to-brittle transition phase, monel remains unaffected, despite being cooled to the temperature of liquid hydrogen, that is -252.8°C.

Monel and phosphor bronze melting point

All alloys have a melting range. It is difficult to pinpoint the exact temperature when an alloy melts, solely because an alloy consists of several metals or metalloids in its chemistry. And therefore, the melting range or the temperature range where the alloy has turned into sludge is taken into account. Most monel alloys have a melting range between a temperature range of 2372°F - 2462°. And the melting range for Phosphor bronze lies anywhere between a temperature range of 1705°F (Liquidus) - 1940°F (Solidus).

Monel alloy chemical composition

Trade Name ASTM/AISI

Alloy type

UNS %Cu %Al %Ti %Fe %Mn %Si %Ni
Monel 400 B 127, B 164 N04400 28-34 2.5 max 2.0 max 0.5 max 63 min
Monel 401 N04401 28-34 2.5 max 2.0 max 63 min
Monel 404 N04404 Rem 0.05 max 0.5 max 0.1 max 0.1 max 52-57
Monel K-500 B 865 N05500 27-33 2.3-3.15 0.35-0.85 2.0 max 1.5 max 0.5 max 63 min
Monel 405 B 164 N04405 28-34 2.5 max 2.0 max 0.5 max 63 min

Monel physical & mechanical properties

  Density Melting Point Tensile Strength Yield Strength (0.2%Offset) Elongation
Monel 400 8.8 g/cm3 1350 °C (2460 °F) Psi – 80000 , MPa – 550 Psi – 35000 , MPa – 240 40 %
Monel 404 8.91 gm/cm3 1300 - 1350℃ 70 KSI min (483 MPA min) 25 KSI min (172 MPA min) 35 %
Monel 405 8.80 g/cm3 1300 - 1350°C 550 Mpa 240 Mpa 40 %
Monel K500 8.44 g/cm3 1350 °C (2460 °F) Psi – 160000 , MPa – 1100 Psi – 115000 , MPa – 790 20 %

Monel Grades & Material Equivalent

GRADES WERKSTOFF NR. UNS GOST AFNOR JIS BS EN
Monel 400 2.4360 N04400 МНЖМц 28-2,5-1,5 NU-30M NW 4400 NA 13 NiCu30Fe
Monel 404 2.4867 N04404          
Monel 405   N04404          
Monel K500 2.4375 N05500          

Phosphor Bronze Grade List

GRADES EQUIVALENT
PB104
CW453K / C52100
PB102
CW451K / C51000
PB1
CC481K / C91700

Density of Phosphor Bronze Alloy

Alloy Approx Density (g/cmᶟ)
PB1 Phosphor Bronze 8.7
LB2 / LB4 / PB2 Phosphor Bronze 8.7

Melting Temperature Point of Phosphor Bronze

831-999  degree celsius

Phosphor Bronze chemical formula

PB1 and Pb2 Phosphor Bronze Chemical Composition

  PB1 Phosphor Bronze Leaded Bronze / Phosphor Bronze LB2 / LB4 / PB2
  Min Max Min Max
Copper 87 89.5 87 89.5
Tin 10.0 11.5 10.0 11.5
Lead   0.25   0.25
Zinc   0.05   0.05
Nickel   0.10   0.10
Phosphorous   1.0   1.0
Aluminium   0.01   0.01
Iron   0.1   0.1
Antimony   0.05   0.05
Manganese   -   0.05
Sulphur   0.05   0.05
Silicon   0.01   0.01
Bismuth   0.05   0.05
Impurities   -   0.05

Phosphor Bronze PB1 & PB2 Equivalent

Pb1 Equivalent Standard

  • BS 1400 PB1
  • BS EN 1982-2008 GC CC481K
  • CuSn11P-C
  • NES 838 Part 1
  • SAE 65c
  • Def Stan 02 838 Part 1
  • ASTM B 505 C90700
  • AS 1565-1985 C90710
  • NES 838
  • AS 1565-1974 904D

Pb2 Equivalent Standard

  • BS EN 1982-2008 GC CC481K
  • UNI 7013-72-2A
  • CuSn11P-C
  • DIN 1705 2.1052.04
  • BS 1400 PB2
  • SAE 65C
  • ASTM B 505 C90700
  • AS 1565-1985 C90810
  • AS 1565-1974 904D

Mechanical Properties of Phosphor Bronze

Phosphor bronze pb2 material properties

Tensile Stress (N/mm²) 400
Hardness Brinell 120
Proof/Yield Stress (N/mm²) 190
Elongation (%) 20
Impact Izod J20°C

Physical Properties of Pb2

Coefficient of Friction
Melting Temperature Range °C 831-999
Thermal Conductivity W/mK 45
Relative Magnetic Permeability
Density g/cm³ 8.8
Electrical Resistivity μΩ.m15°C 0.17
Coefficient of Thermal Expansion 0-250°C 19

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