Aluminium Casting Alloy LM5
This aluminium alloy conforms to BS 1490:1988 LM5Mechanical Properties of aluminium casting alloy LM5 0.2% Proof Stress (N/mm2) 90-110 90-120 Tensile Strength (N/mm2) 140-170 170-280 Elongation (%) 3 5 Impact resistance Izod (Nm) 7.9 12.6 Brinell Hardness 50-70 60-70 Modulus of Elasticity (x103 N/mm2) 71 71 Shear Strength (N/mm2) 140 -
Strength at elevated temperatures
Room temperature properties are largely maintained up to 200°C, but fall rapidly above 300°C.
Physical Properties of aluminium casting alloy LM5 Coefficient of Thermal Expansion (per °C @ 20-100°C) 0.000023 Thermal conductivity (cal/cm2/cm/°C @ 25°C) 0.33 Electrical conductivity (% copper standard @ 20°C) 31.0 Density (g/cm3) 2.65 Freezing range (°C) approx. 12
Machinability
LM5 machines very well and takes an excellent polish.
Corrosion Resistance
LM5 is highly resistant to corrosion under most conditions and is superior to all other aluminium alloys for marine use.
Anodising
LM5 may be anodised by any of the more common processes. A transparent colourless-to-whitish film is obtained according to the process used, and is suitable for decorative finishing.
Application and General notes
LM5 is used where very high resistance to corrosion from sea water or marine atmospheres is required, for equipment used for the manufacture of foodstuffs, cooking utensils and chemical plant, and for an aluminium casting which needs to exhibit and maintain a surface of high polish. Applications include, for example, door furniture, car fittings and trim, and similar aluminium castings where a colourless anodic film is required.
LM5 is mainly used for sand casting and, to a lesser extent, for gravity die casting, but high pressure aluminium die castings of relatively simple shapes has been made. LM5 is not heat-treated.