Aluminium Casting Alloy LM16
This alloy conforms to BS 1490:1988 LM16. Castings are standardised in the solution treated and naturally aged (TB) condition and in the fully heat treated (TF) condition.Mechanical Properties
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|
TB Sand Cast |
TF Sand Cast |
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|
0.2% Proof Stress (N/mm2) |
120-140 |
140-150 |
220-280 |
250-300 |
|
Tensile Strength (N/mm2) |
170 |
230 |
230-290 |
280-320 |
|
Elongation (%) |
2 |
3 |
0-1 |
0-2 |
|
Impact resistance Izod (Nm) |
1.4 |
2.7 |
1.0 |
1.4 |
|
Brinell Hardness |
80 |
85 |
100 |
110 |
|
Modulus of Elasticity (x103 N/mm2) |
71 |
71 |
71 |
71 |
|
Shear Strength (N/mm2) |
- |
- |
200 |
235 |
Strength at elevated temperatures
LM16 retains its strength well, up to 200°C
Physical Properties
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|
|
|
Coefficient of Thermal Expansion (per °C @ 20-100°C) |
0.000023 |
|
Thermal conductivity (cal/cm2/cm/°C @ 25°C) |
0.34 |
|
Electrical conductivity (% copper standard @ 20°C) |
39 |
|
Density (g/cm3) |
2.70 |
|
Freezing range (°C) approx. |
620-550 |
Machinability
The heat-treated alloy has fairly good machining properties, but tools, which should preferably be of high speed steel, must be kept sharp. A moderately high rate of tool wear may be expected. Liberal cutting lubricant should be employed.
Corrosion resistance
The alloy has fairly good resistance to corrosion under atmospheric conditions.
Anodising
A protective film, usually greyish in colour, may be obtained by either the sulphuric or chromic acid process.
Heat Treatment
Full heat treatment gives high strength and hardness
Applications and General Notes
LM16 alloy is used for water-cooled cylinder heads, valve bodies, water jackets, cylinder blocks, fire hose couplings, air compressor pistons, fuel pump bodies, aircraft supercharger covers and similar applications where leak-proof castings having the high strength produced by heat treatment are required. It is equally suitable for sand casting and for gravity die casting. LM16 has good weldability.