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Quick Links Aluminium Alloys : Standard Aluminium Alloys Special Aluminium Alloys : Cooper Alloys

Aluminium alloys

Mechanical Properties

Metal UTS N/mm2 TPSI 0.2% Proof N/mm2 >TPSI Elong % BH Density LM25M 130 150 8.0 10.0 80 100 5.0 6.5 2.0 3.0 55 65 2.68 LM25TF 230 280 15.0 18.0 200 250 13.0 16.0 0.0 2.0 90 100 2.68 LM25TB7 160 10.0 80 110 5.0 7.0 2.5 65 75 2.68 2L99 230 14.8 185 12.0 2.0 80 2.68 A356T6 234 15.0 166 10.8 5.0 70 100 2.68 356F 130 8.4 120 80 2.0 55 2.68 356T6 207 13.3 138 8.9 3.0 70 2.68 356T7 214 13.8 126 8.1 3.0 75 2.68 356T51 159 10.2 110 7.1 3.0 60 2.68 356T71 172 11.1 124 8.0 3.0 60 2.68 40E 215 13.9 170 11.0 4.0 60 100 2.68 712 224 14.4 172 11.1 4.0 75 2.80 LM31 215 13.9 170 11.0 4.0 60 100 2.80 Vanasil 170 11.0 140 9.0 0.5 100 2.80

Comparision with International Specifications

BSI1490 ISO France Germany USA Aerospace LM25 AlSi7Mg A-S7g G-AISi7Mg A256 BS2L99 BSL173 BSL174

Comparison of LM25 physical properties with 6061 & 6082 wrought aluminium

LM25 6061 6082 Thermal Conductivity (% IACS) 38.4 39.6 43.7 Coefficient of linear expansion (20-100° C) 22x10-6 24x10-6 23x10-6 Electrical Conductivity (%IACS @ 20°C) 39 43.1 43.7 Hardness (Brinell) 60 - 105 60 - 100 60 -100 Modulus of Elasticity 71 69 69

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Standard Aluminium alloys

Silicon Magnesium series
These alloys are the best general purpose high strength cast alloys available and can be supplied with a variety of heat treatments They also have good salt water corrosion resistance. They can be anodised to produce a thick black colour. Decorative anodising is not possible due to the metallic silicon content.

A356 - An American specification introduced into the UK by Micro Metalsmiths in 1964. It is generally made available for American Military specifications.

LM25 - Our most commonly used cast aluminium alloy and can be supplied as cast or heat treated.

2L99 - This is a more tightly controlled version of LM25 for aerospace applications.

Zinc Magnesium series
These alloys are less easy to cast because of their high viscosity in the liquid state.

40E - This alloy is particularly suitable for castings which require flame or dip brazing. Components using this material should have uniform wall sections. To achieve corrosion resistance an additional surface treatment such as anodising or chromatic conversion is necessary. The material machines very well and is self ageing at room temperature over about three weeks.

712/LM31 - These alloys are similar to 40E but specific to defence and approved for certain space applications.

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Special Aluminium alloys

6061 - Micro Metalsmiths produces a cast version of this well known wrought material as an alternative to 40E, insofar as it is dip-brazeable. It is more resistant to stress corrosion and is approved for certain space applications.

Vanasil - Micro Metalsmiths has pioneered the use of this difficult material. It is a very high silicon alloy which has a relatively low co-efficient of expansion which is compatible with stainless steel between -50 C to / +70 C. It is used in the manufacture of gyroscopes and highly-stressed pistons.

Aluminium and copper alloys are non-magnetic whilst retaining excellent thermal and electrical conductivity. This is becoming of increasing importance in numerous applications.

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Copper Alloys

Some modern copper alloys have properties equal to or better than the more commonly specified steels. In respect of corrosion resistance copper, gun metal or aluminium bronze is often superior to stainless steel particularly in low oxygen environments. Certain high specification aluminium bronzes have extremely high wear resistance and good anti-galling properties.

Mechanical Properties

Metal UTS 0.2% Proof Elong BHN Density N/mm2 TPSI N/mm2 TPSI % Silicon Brass MB1 479 31 200 13 25 70 100 8.5 Aluminium Bronze AB2 640 41 250 16 13 140 190 8.3 Manganese Bronze HTB1 470 30 170 11 18 150 8.4 Manganese Bronze HTB3 740 48 400 26 11 190 8.4 Die Casting Brass DCB3 290 19 90 6 15 60 70 8.4 Silver Bronze SB1 450 30 180 11 5 100 130 8.7

Comparison with International Specyfications

MM Spec. BS1400 France Germany USA MB1 ASTM B584 & C87500 AB2 AB2 DIN1714 ASTM B148 HTB1 HTB1 DIN1709 ASTM B147 HTB3 HTB3 DIN1709 ASTM B147 DCB3 DCB3 NF A 53-703

Comparison to Mechanical properties of Stainless Steel

Metal UTS 0.2% Proof Elong BHN Density N/mm2 TPSI N/mm2 TPSI % 304 515 205 40 201 8.0 304L 485 170 40 201 8.0 316L 485 170 40 217 8.0 EN8 61 42 18

Copper alloys

Silicon Brass-MB1 - The most commonly cast copper alloy. It offers high wear resistance particularly in well-lubricated conditions. Silicon aids fluidity during the casting process, increases the tensile strength by approximately 50% compared with normal copper-zinc alloys, and promotes resistance to dezincification. MB1 is a viable alternative to mild steel for many applications.

Aluminium Bronze-AB2 - This alloy is noted for its corrosion resistance, good tensile strength, and retention of its properties at higher temperatures. The oxide film which forms on the liquid material requires the use of relatively high cost pouring systems.

Manganese Bronze-HTB3 - A highly alloyed brass which offers higher tensile strength and loadings than MB1, but lower elongation. The tendency to produce zinc dross, when in the liquid state, leads to a lower surface finish than MB1.

Manganese Bronze-HTB1 - A medium strength alloy suitable for soldering. 
It offers good machineability.

Die Casting Brass-DCB3 - A low strength material also suitable for soldering. 
It offers good machineability.

Silver Bronze-SB1 - This unusual silver coloured material is an alloy of copper / nickel / manganese, with high resistance to salt water corrosion and erosion. 
The alloy is difficult to handle and should only be specified in premium applications 
and after consultation.

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