Smithells Light Metals Handbook Part 6 pptx

72 Smithells Light Metals HandbookTable 4.2 ALUMINIUM-SILICON-COPPER ALLOYS LM16TF Related British Specifications LM2MGe LM4MGe Ge SP 3L78 LM21MSP Composition % Single figures indicate m

Table 4.1 (continued )

Specification BS 1490: 1988

0.5, P§

Properties of material

Suitability for:

requirement

Special properties Readily welded General purpose high-strength casting alloy More suited to chill (grav, die) casting

Piston alloy

Mechanical properties sand cast SI units (Imperial units in brackets)

Tensile stress min., MPa

(7.8 9.7)

80 110 (5.2 6.5)

200 250 (12.9 16.2)

Mechanical properties chill cast SI units (Imperial units in brackets)

Tensile stress min., MPa

130-200(8.4 12.9)

(14.2 16.8)

(11.0 12.3)

†If Ti alone is used for grain refinement then Ti 6< 0.05% E Excellent F Fair G Good P Poor U Unsuitable

‡Fully heat-treated (Ge General purpose alloy; SP Special purpose alloy as per BS: 1490: 1988)

§Refine with phosphorus-subject to examination under microscope

ŁŁOr for such time to give required BHN

72 Smithells Light Metals Handbook

Table 4.2 ALUMINIUM-SILICON-COPPER ALLOYS

LM16TF

Related British Specifications LM2M(Ge) LM4M(Ge) (Ge) (SP) 3L78 LM21M(SP)

Composition % (Single figures indicate maximum) | {z } | {z }

Properties of material

Suitability for:

Heat treatment

70 80°C 70 80°C 70 80°C

Special properties Alloy for General engineering alloy Pressure tight High Equally

pressure Can tolerate relatively strength alloy in TF suited to all

Mechanical properties sand cast SI units (Imperial units in brackets)

Tensile stress min MPa

Expected 0.2% proof stress,

(4.5 7.1) (12.9 16.2) (7.8 9.1) (14.2 18.1) (5.2 9.1)

Mechanical properties chill cast SI units (Imperial units in brackets)

Tensile strength min MPa

Expected 0.2% proof stress,

(5.8 8.4) (5.2 7.1) (12.9 19.4) (9.1 9.7) (16.2 19.4) (5.2 9.1)

†Not normally used in this form

‡The use of die castings is usually restricted to only moderately elevated temperatures

Aluminium and magnesium casting alloys 73

Table 4.2 (continued )

Specification BS 1490: 1988 LM22TB LM24M LM26TE LM27M LM30M LM30TS

Related British Specifications (SP) (Ge) (SP) (Ge) (SP) (SP)

Properties of material

Suitability for:

Heat treatment

Solution temperature,°C 515 530

Special properties Chill casting Alloy for Piston alloy, Excellent Alloy for pressure die

alloy (grav pressure retains castability casting automobile engine

and hardness at elevated temps

Mechanical properties sand cast SI units (Imperial units in brackets)

Tensile stress min., MPa

Expected 0.2% proof stress,

(5.2 5.8)

Mechanical properties chill cast SI units (Imperial units in brackets)

HB D 90 120 Tensile strength min., MPa

Expected 0.2% proof stress,

(7.1 7.8) (6.7 7.7) (10.4 12.3) (5.8 7.1) (9.7 12.9) (10.4 12.9)

Note:

Table 4.3 ALUMINIUM-COPPER ALLOYS

Aerospace

Composition % (Single figures indicate maximum)

0.05 0.30

Nb 0.05 0.3

Properties of material

Suitability for:

(minimum)††

Water at

Grav die alloy

Mechanical properties sand cast SI (Imperial units in brackets)

Tensile stress min., MPa

Expected 0.2% proof stress,

min., MPa

Mechanical properties chill cast SI units (Imperial units in brackets)

Tensile stress min., MPa

Expected 0.2% proof stress,

min., MPa

†[ ] signifies obsolete specification E Excellent F Fair G Good P Poor U Unsuitable

‡Si C Fe 1.0 max (Ge General purpose alloy; SP Special purpose alloy as per BS 1490: 1988)

§Or 5 days ageing at room temp

ŁŁCan substitute stabilizing treatment at 200 250°C if used for pistons

††Allow to cool to 480°C before quench.

76 Smithells Light Metals Handbook

Table 4.4 MISCELLANEOUS ALUMINIUM ALLOYS

Aerospace

Composition % (Single figures indicate maximum)

Other

Properties of material

Suitability for:

Heat treatment

Mechanical properties Sand cast SI units (Imperial units in brackets)

Tensile stress min,

Expected 0.2% proof stress,

(11.0-12.3)

Mechanical properties chill cast SI units (Imperial units in brackets)

Tensile stress min,

†0.05% min if Ti alone used for grain refinement

††Not normally used in this form

§Or 8 h at 435 445 C then raise to 490 500 C for further 8 h and quench as in table

Aluminium and magnesium casting alloys 77

Table 4.4 (continued )

Aerospace

Composition % (Single figures indicate maximum)

Properties of material

Suitability for:

Heat treatment

Oil or air blast

Mechanical properties sand cast SI units (Imperial units in brackets)

Tensile stress min,

Expected 0.2% proof stress,

HB100 140

Mechanical properties chill cast SI units (Imperial units in brackets)

Tensile stress min,

Expected 0.2% proof stress

HB 100 140

‡‡Alternative-room temp age-harden for 3 weeks

Note:

Table 4.5 HIGH STRENGTH CAST AL ALLOYS BASED ON AL-4.5 CU

Designation

Al Assoc (USA)

Aluminium and magnesium casting alloys 79

Table 4.6 MINIMUM REQUIREMENTS FOR SEPARATELY CAST TEST BARS

Alloy Sand/Die TreatmentŁ MPa MPa or 4 ð diam 500 kgf 10 mm

Table 4.7 TYPICAL PROPERTIES OF SEPARATELY CAST TEST BARS

Alloy Sand/Die TreatmentŁ MPa MPa or 4 ð diam 500 kgf 10 mm

Table 4.8 ZIRCONIUM-FREE MAGNESIUM ALLOYS

Grain refined (0.05 0.2 mm chill cast) when superheated to 850 900°C or suitably treated with carbon (as hexachlorethane)

Composition % (Single figures indicate maximum)

Material properties

°

Solution:

Equivalent DTD

Composition % (Single figures indicate maximum)

Material properties

continued overleaf

Table 4.8 (continued )

Heat treatment

Solution:

BSS L series

Equivalent DTD

Composition % (Single figures indicate maximum)

Cu C Si C Fe C Ni

Material properties

°

Heat treatment continued

Precipitation:

Time, h

Stress relief:

Mechanical propefties sand cast (SI units first, Imperial units following in brackets)

Mechanical properties chill cast (SI units first, Imperial units following in brackets)

continued overleaf

Table 4.8 (continued )

ASTM designation

Equivalent DTD

Precipitation:

Stress relief:

Mechanical properties sand cast (SI units first, Imperial units following in brackets)

Mechanical properties chill cast (SI units first, Imperial units following in brackets)

Increased proof stress after full heat treatment