Handbook Properties and Selection Nonferrous Alloys and Spl Purpose Mtls (1992) WW Part 7 potx

Table 1 Typical mechanical properties of AZ10A at room temperature Tensile strength Yield strength Compressive yield strength Size and shape MPa ksi MPa ksi Elongation, % MPa ksi

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°F) for 2 h and slowly cooling However, such treatment causes some loss of strength in AZ31B-H24 sheet products If distortion of part is observed after rough machining, the cutting tool should be inspected to ensure that it is sharp and properly ground If so, the size of cut should be decreased With complex parts or parts machined to extremely close tolerances, it may be advisable to stress relieve or, if time permits, to store parts for 2 or 3 days between rough machining and finishing

Design and Weight Reduction

By substituting magnesium alloys for heavier metals such as steel and aluminum alloys, many structural parts can be substantially reduced in weight with little or no redesign This is possible because manufacturing limitations make many parts heavier than necessary For example, for successful filling of the mold, a casting may require a minimum wall thickness greater than that dictated by service requirements and the strength of the metal used Similarly, forgings and extrusions sometimes must be made thicker than necessary, and the light weight of magnesium can be used to advantage

In many instances, a casting, forging, or extrusion for which magnesium is substituted for a heavier metal can have adequate strength with no increase in wall thickness

In other parts, substitution of magnesium may require greater wall thickness, and substantial redesign may be necessary in order to realize maximum weight savings Because strength and stiffness in bending of many structural sections increase approximately as the square and cube of the section depth, respectively, it is possible to obtain large increases in strength and stiffness with moderate increases in depth and cross-sectional area When such increases in depth are permissible, it usually is economical to redesign the part for magnesium The greater bulk of the redesigned part reduces local instability, and although the saving in weight is less than maximum, the reduction in instability allows design simplification and thus reduces manufacturing costs

The room-temperature thickness, strength, stiffness, and weight of magnesium alloys are compared with those of aluminum alloys and steel in Table 27 Bending strength is defined as the product of yield strength and section modulus

Table 27 Relative bending strength, stiffness, and weight of selected structural metals

strength

Stiffness Weight

For equal thickness

1025 steel 100 100.0 100.0 100.0

6061-T6 aluminum sheet and extrusions 100 97.2 34.5 34.5

AZ31B magnesium extrusions 100 47.2 22.4 22.5

ZK60A-T5 magnesium extrusions 100 88.9 22.4 22.5

AZ31B-H24 magnesium sheet 100 73.4 22.4 22.5

For equal bending strength

1025 steel 100 100 100.0 100.0

6061-T6 aluminum sheet and extrusions 101 100 35.8 34.8

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AZ31B magnesium extrusions 146 100 69.2 32.9

ZK60A-T5 magnesium extrusions 106 100 26.7 23.9

AZ31B-H24 magnesium sheet 117 100 35.6 26.3

For equal stiffness

1025 steel 100 100 100 100.0

6061-T6 aluminum sheet and extrusions 143 199 100 49.2

AZ31B magnesium extrusions 165 129 100 37.2

ZK60A-T5 magnesium extrusions 165 242 100 37.2

AZ31B-H24 magnesium sheet 165 200 100 37.2

For equal weight

1025 steel 100 100 100 100

6061-T6 aluminum sheet and extrusions 290 817 841 100

AZ31B magnesium extrusions 444 930 1962 100

ZK60A-T5 magnesium extrusions 444 1753 1962 100

AZ31B-H24 magnesium sheet 444 1451 1962 100

Note: Comparison made at room temperature for rectangular beams of constant width with the following minimum yield strengths:

1025 steel, 250 MPa (36 ksi); 6061-T6 aluminum, 240 MPa (35 ksi); magnesium alloys, average of minimum tensile yield and compressive yield strengths All comparisons expressed in percent

Bending. Rectangular steel, aluminum, and magnesium sections of equal thickness have rigidities in the ratio of their moduli of elasticity The magnesium section weighs about 63% as much as the aluminum section and about 22% as much

as the steel section

The rigidity in bending of a rectangular section is proportional both to the cube of its depth and to its modulus of elasticity If the section thicknesses of a magnesium section, an aluminum section, and a steel section are adjusted until their rigidities are equal, the magnesium section will weigh about 71% of the aluminum and about 40% of the steel If the section thickness of the magnesium is increased to about twice that of the steel, the magnesium will be more than 70% more rigid than the steel and less than 50% as heavy Magnesium supporting its own weight shows no more deflection than other metals under the same conditions

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At high temperatures, the difference between short-time ultimate and yield strengths of certain magnesium alloys decreases significantly Creep properties that depend on time must also be considered in evaluating materials for long-time operation at elevated temperature Creep-strength values of several magnesium alloys are given in the data compilations in the article "Properties of Magnesium Alloys" in this Volume

Plate Buckling. Structures subjected to compressive loads may be limited in efficiency (load carried versus weight of structure) by buckling at relatively low stresses

A structural index is a valuable aid to designers in the selection of optimum materials for plate structures that are critical

in compression loading A structural index is nondimensional; that is, equivalent designs give the same value of structural

index regardless of the size of the actual part The plate-buckling index is computed from the maximum edge load (Pcr)

that will not cause crippling, the width (b) of the plate and a factor, K, determined by the amount of restraint or clamping along the unloaded edges for a simply supported edge, K = 4.0) The formula is:

0,5

²

cr

P k Index

b

=

Using this index, the efficiency of various structural materials can be directly compared for given conditions of loading and structural configuration For example, the efficiencies of three materials at room temperature and at 260 °C (500 °F) for plate-buckling indexes up to 4000 are shown in Fig 19 Comparisons are based on typical properties after short-time exposure at temperature

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Fig 19 Effect of plate-buckling index and temperature on the structural efficiency of magnesium, aluminum,

and titanium alloys See text for discussion

A low value of plate-buckling index means either that the critical edge load is low or that the plate is wide, corresponding

in either instance to a more lightly stressed structure As the index value increases, it represents a transition to narrower plates and/or heavier edge loads and, at high values, corresponds to a condition of pure prismatic compression

The ratio of working stress to density is an inverse measure of structural weight the higher the ratio, the lighter the structure Figure 19 shows the expected advantage in efficiency of the lowest-density magnesium alloy HK31A-H24 over the higher-density aluminum and titanium alloys This advantage fades as the index increases, and the stress condition moves from elastic buckling toward prismatic compression Comparison of the two charts shows that the range over which the magnesium alloy is the most efficient of the three alloys (magnesium, aluminum, and titanium) is higher at 260

°C (500 °F) than at room temperature

Wrought Magnesium Alloys

Composition limits. 1.0 to 1.5 Al, 0.2 to 0.6 Zn, 0.2

Mn min, 0.1 Si max, 0.1 Cu max, 0.005 Ni max, 0.005

Fe max, 0.04 Ca max, bal Mg

Applications

Typical uses. Low-cost extrusion alloy with moderate mechanical properties and high elongation Used in as-extruded (F) temper

Mechanical Properties

Tensile properties. See Table 1

Table 1 Typical mechanical properties of AZ10A at room temperature

Tensile strength

Yield strength

Compressive yield strength Size and shape

MPa ksi MPa ksi

Elongation,

%

MPa ksi

Solid shapes with least dimension up to 6.4 mm (0.025 in.) 240 35 145 21 10 69 10

Solid shapes with least dimension to 6.4 to 38 mm (0.025 to 1.5 in.) 240 35 150 22 10 76 11

Hollow and semihollow shapes 230 33 145 21 8 69 10

Tube (152 mm, or 6 in OD max) with 0.7 to 6.4 mm (0.028 to 0.25

in.) wall

230 33 145 21 8 69 10

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Elastic modulus. Tension, 45 GPa (6.5 × 10 psi)

to 0.25 Ca, 0.15 Mn max, 0.05 Si max, 0.05 Cu max,

0.005 Fe max, 0.002 Ni max, 0.3 max other, bal Mg

AMS. AZ31B sheet: O temper, 4357; H24 temper, 4376

ASTM. Sheet: B 90 Extruded rod, bar, shapes, tubing,

and wire: B 107, AZ31B forgings: B 91

SAE. AZ31B: J466 Former SAE alloy number: 510

UNS numbers. AZ31B: M11311 AZ31C: M11312

Government. AZ31B: forgings, sheet, and plate,

QQ-M-40; extruded bar, rod, and shapes, QQ-M-31B;

extruded tubing, WW-T-825B

Foreign. Elektron AZ31 (extruded bar and tubing)

British: sheet, BS 3370 MAG111; extruded bar and

tubing, BS 3373 MAG111 German: DIN 9715 3.5312

French: AFNOR G-A371

Chemical Composition

Composition limits of AZ31B. 2.5 to 3.5 Al, 0.20

Mn min, 0.60 to 1.4 Zn, 0.04 Ca max, 0.10 Si max, 0.05

Cu max, 0.005 Ni max, 0.005 Fe max, 0.30 max other (total); bal Mg

Composition limits of AZ31C. 2.4 to 3.6 Al, 0.15

Mn min, 0.50 to 1.5 Zn, 0.10 Cu max, 0.03 Ni max, 0.10

Si max, bal Mg

Consequence of exceeding impurity limits.

Excessive Cu, Ni, or Fe degrades corrosion resistance

Applications

Typical uses. AZ31B and AZ31C: forgings and extruded bar, rod, shapes, structural sections, and tubing with moderate mechanical properties and high elongation; AZ31C is the commercial grade, with the same properties as AZ31B but higher impurity limits AZ31B only: sheet and plate with good formability and strength, high resistance to corrosion, and good weldability AZ31B and AZ31C are used in the asfabricated (F), annealed (O), and hard-rooled (H24) tempers

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Tensile properties. See Tables 2 and 3

Table 2 Typical room-temperature mechanical properties of AZ31B

Tensile yield strength (a)

Hardness Shear

strength

Compressive yield strength (a)

Ultimate bearing strength (d)

Bearing yield strength (d)

Forgings 260 38 170 25 15 50 59 130 19

16 in.) pin diameter

Table 3 Typical tensile properties of AZ31B at various temperatures

Testing temperature Tensile strength Yield strength

Elongation in 50

mm (2 in.), %

Sheet, hard rolled

-80 -112 331 48.0 234 34.0

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Shear strength. See Table 2

Compressive yield strength. See Table 2

Bearing properties. See Table 2

Hardness: See Table 2

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Latent heat of fusion. 330 to 347 kJ/kg (142 to 149 Btu/lb)

Thermal conductivity. 96 W/m · K (56 Btu/ft · h · °F) at 100 to

AMS. Extrusions: 4350 Forgings: 4358

ASTM. Extrusions: B 107 Forgings: B 91

SAE. J466 Former SAE alloy numbers: 520

(extrusions) and 531 (forgings)

UNS number. M11610

Government. Extruded bar, rod, and shapes: 31B Extruded tubing: WW-T-825A Forgings: QQ-M-40B

QQ-M-Foreign. Elektron AZ61 (extruded bar, sections, and tubing) British: extruded bar, sections, and tubing, BS

3373 MAG121; forgings, BS 3372 MAG121 German: DIN 9715 3.5612; castings, DIN 1729 3.5612 French: AFNOR G-A6Z1

MPa ksi MPa ksi

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Composition limits. 5.8 to 7.2 Al, 0.15 Mn min, 0.40

to 1.5 Zn 0.10 Si max, 0.05 Cu max, 0.005 Ni max,

0.005 Fe max, 0.30 max other (total), bal Mg

Excessive Cu, Ni, or Fe degrades corrosion resistance

Applications

Typical uses. General-purpose extrusions with good properties and moderate costs, and forgings with good mechanical properties; used in the as-fabricated (F) temper This alloy is used in sheet form for battery applications only

Table 5 Typical room-temperature mechanical properties of AZ61A-F

Hardness Shear

strength

Sheet 305 44 220 32 8 150 22

Table 6 Typical properties of AZ61A-F extrusions at various temperatures

Temperature Tensile strength Yield strength

Elongation in

50 mm (2 in.), %

-185 -300 379 55.0 317 46.0 4

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Hardness. See Table 5

Poisson's ratio. 0.35

Elastic modulus. Tension, 45 GPa (6.5 × 106 psi);

shear, 17 GPa (2.4 × 106 psi)

Impact strength. Charpy V-notch: forgings, 3 J (2.2

ft · lbf); extruded rod, bar, and shapes, 4.1 J (3.0 ft · lbf)

Incipient melting temperature. 418 °C (785 °F)

Coefficient of linear thermal expansion. 26

μm/m · K (14 μin./in · °F) at 20 °C (68 °F)

Specific heat. 1.05 kJ/kg · K (0.25 Btu/lb · °F) at 25

°C (78 °F)

Latent heat of fusion. 373 kJ/kg (160 Btu/lb)

Thermal conductivity. 80 W/m · K (46 Btu/ft · h ·

Recrystallization temperature. Recrystallizes after

1 h at 288 °C (550 °F) following 20% cold work

Annealing temperature. 345 °C (650 °F)

Hot-working temperature. 230 to 400 ° (450 to 750

°F)

Hot-shortness temperature. 415 °C (780 °F)

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Government. Extruded bar, rod, and shapes:

31B Extruded tubing: WW-T-825 Forgings:

QQ-M-40B

Composition limits. 7.8 to 9.2 Al, 0.20 to 0.80 Zn,

0.12 Mn min, 0.10 Si max, 0.05 Cu max, 0.005 Ni max, 0.005 Fe max, 0.30 max other (total), bal Mg

Excessive Si, Cu, Ni, or Fe degrades corrosion resistance

Applications

Typical uses. Extruded products and press forgings This alloy can be heat treated

Table 7 Typical room-temperature mechanical properties of AZ80A

Hardness Shear

strength

Compressive yield strength

Ultimate bearing strength

Bearing yield strength

Aged (T5

temper)

345 50 250 36 6 72 82 160 23 195 28

Bar, rod, and shapes

(a) At 0.2% offset

(b) In 50 mm (2 in.)

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Table 8 Typical mechanical properties of AZ80A-F at various temperatures

shear, 17 GPa (2.4 × 106 psi)

Annealing temperature. 385 °C (725 °F)

Hot-working temperature. 320 to 400 °C (600 to

750 °F)

Hot-shortness temperature. 415 °C (775 °F)

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HK31A

See also cast alloy HK31A

Specifications

AMS. Annealed sheet and plate: 4384E

ASTM. Sheet and plate: B 90

SAE. J465 Former SAE alloy number: 507

Tensile properties. Tensile strength: H24 temper,

260 MPa (38 ksi); O temper, 230 MPa (33 ksi) Yield strength: H24 temper, 205 MPa (30 ksi); O temper, 140 MPa (20 ksi) Elongation in 50 mm (2 in.): O temper, 23%; H24 temper, 9%

Tensile properties versus temperature. See Table 9 and Fig 1 and 2

Table 9 Typical tensile properties of HK31A-H24 sheet at elevated temperatures

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Fig 1 Typical stress-strain curves for 1.63 mm (0.064 in.) thick HK31A-H24 sheet

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Fig 2 Typical stress-strain curves for 1.63 mm (0.064 in.) thick HK31A-0 sheet

Compressive yield strength. O temper: 97 MPa (14

ksi) at 21 °C (70 °F) H24 temper: 160 MPa (23 ksi) at

21 °C (70 °F); 150 MPa (22 ksi) at 204 °C (400 °F) See

also Fig 1 and 2

Bearing properties. H24 temper: ultimate bearing

strength, 420 MPa (61 ksi); bearing yield strength, 285

Creep characteristics. See Fig 3 and 4

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Fig 3 Isochronous stress-strain curves for 1.63 mm (0.064 in.) thick HK31A-H24 sheet Specimens exposed at

testing temperatures for 3 h before loading

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Fig 4 Isochronous stress-strain curves for 1.63 mm (0.064 in.) thick HK31A-0 sheet Specimens exposed at

testing temperatures for 3 h before loading

Thermal conductivity. See Table 10

Table 10 Thermal conductivity of HK31A sheet and plate at various temperatures

Testing temperature Thermal conductivity

°C °F W/m · K Btu/ft · h · °F

H24 temper

18 65 114 66

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Weldability. Gas-shielded arc welding with HK 31A

or EZ33A rod (EZ33A preferred), excellent; stress relief can be used for sheet and plate, but is not required Resistance welding excellent

HM21A

Specifications

AMS. Sheet and plate: 4390 Forging: 4363

ASTM. Sheet and plate: B 90 Forging: B 91

Applications

Typical uses. Sheet, plate, and forgings in the solution-heat-treated, cold-worked, and annealed condition (T8 temper), usable to 343 °C (650 °F) and above

Tensile properties. T8 temper: tensile strength, 235 MPa (34 ksi); yield strength at 0.2% offset, 170 MPa (25 ksi)

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Shear strength. 125 MPa (18 ksi)

Compressive yield strength. 130 MPa (19 ksi)

Tensile and compressive properties versus temperature. See Table 11 and Fig 5

Table 11 Typical tensile and compressive properties of HM21A at elevated temperatures

Testing temperature Tensile strength Tensile

yield strength

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Fig 5 Typical stress-strain curves for HM21A-T8 sheet Specimens held at test temperature 3 h before testing

Bearing properties. Ultimate bearing strength, 415

MPa (60 ksi); bearing yield strength, 270 MPa (39 ksi)

Table 12 Typical creep properties of HM21A-T8 sheet

Stress to produce, in 100 h, extension of Testing temperature

0.1% (creep) 0.2% (total) 0.5% (total)

150 300 103 14.9 80 11.5 108 15.6

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Fig 6(b) Isochronous stress-strain curves for HM21A-T8 sheet tested at 427 and 482 °C (800 and 900 °F)

Specimens held at test temperature 3 h before testing

Thermal conductivity. H24 temper, 134 W/m · K

(77 Btu/ft · H · °F); O temper, 138 W/m · K (80 Btu/ft · h

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Applications

Typical uses. Weldable alloy developed primarily for

elevated-temperature structural service in the form of

extruded bar, rod, shapes, and tubing Exposure to

temperatures up to 315 °C (600 °F) for 1000 h causes

virtually no change in short-time room- and

elevated-temperature properties Superior elastic modulus,

particularly at elevated temperatures Although certain extruded sections develop optimum properties in the as-extruded (F) temper, other sections require aging to the T5 temper

Tensile properties. See Table 13 and Fig 7

Table 13 Typical tensile and compressive properties of HM31A extrusions up to 2600 mm 2 (4 in 2 ) in area

Testing temperature Tensile strength Tensile

yield strength

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Fig 7 Typical stress-strain curves for HM31A extrusions Tested in longitudinal direction

Shear strength. Punch, 150 MPa (22 ksi) at 21 °C

(70 °F)

Bearing properties. As 21 °C (70 °F): ultimate

bearing strength, 480 MPa (70 ksi); bearing yield

strength, 345 MPa (50 ksi)

Elastic modulus. Tension: 45 GPa (6.5 × 106 psi) at

21 °C (70 °F); 42 GPa (6.1 × 106 psi) at 150 °C (300 °F);

40 GPa (5.9 × 106 psi) at 200 °C (400 °F); 39 GPa (5.6 ×

106 psi) at 315 °C (600 °F) Shear: 17 GPa (2.4 × 106psi) at 21 °C (70 °F)

Creep characteristics. See Table 14

Table 14 Typical creep properties of HM31A extrusions

Stress to produce, in 100 h, extension of Testing temperature

0.1% (creep) 0.2% (total) 0.5% (total)

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Thermal conductivity. 104 W/m · K (60 Btu/ft · h ·

Hot-working temperature. 370 to 540 °C (700 to

1000 °F)

M1A

Specifications

ASTM. Extruded rod, bar, shapes, and tubing: B 107

Government. Extruded bar, rod, and shapes:

QQ-M-31 Extruded tubing: WW-T-825 Forgings: QQ-M-40

Sheet and plate: QQ-M-54

Foreign. Elektron AM503 British: BS 3370 MAG101

German: DIN 9715 3.5200

Composition limits. 1.2 Mn min, 0.30 Ca max, 0.05

Cu max, 0.01 Ni max, 0.10 Si max, 0.30 max others (total), bal Mg

Excessive Si tends to precipitate Mn Excessive Cu or Ni degrades corrosion resistance in salt water

Applications

Typical uses. Wrought products with moderate mechanical properties as well as excellent weldability, corrosion resistance, and hot formability; not heat treatable

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Table 15 Typical room-temperature mechanical properties of M1A

Hardness Shear

strength

Sheet, hard rolled 240 35 180 26 7 54 65 115 17 125 18 395 57 270 39

Extruded bar and

Forgings 250 36 160 23 7 47 54 110 16

Table 16 Typical tensile properties of M1A at elevated temperatures

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Compressive properties. See Table 15

Directional properties. See Table 17

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Table 17 Typical directional properties of M1A sheet

Tensile strength Yield strength

shear, 17 GPa (2.4 × 106 psi)

Specific heat. 1.05 kJ/kg · K (0.25 Btu/lb · °F)

Thermal conductivity. 138 W/m · K (79.8 Btu/ft · h ·

be done with M1A rod, magnesium flux, and neutral flame

Composition limits. 2.5 to 4.0 Al, 0.08 Mn max, 0.7

to 1.6 Zn, 0.05 Si max, 0.05 Cu max, 0.005 Ni max,

0.005 Fe max, 0.04 Ca max, 0.03 max other impurities (total), bal Mg

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Consequence of exceeding impurity limits. Poor

Coefficient of linear thermal expansion. 26 μm/m · K (14 μin./in · °F)

Specific heat. 1047 J/kg · K (0.25 Btu/lb · °F) at 20 °C (68 °F)

Latent heat of fusion. 330 to 347 kJ/kg (142 to 149 Btu/lb)

Composition limits. 6.0 to 7.0 Zn 1.0 to 1.5 Cu, 0.5

to 1.0 Mn, 0.20 Si max, 0.010 Ni max, 0.30 max other

(total), bal Mg

Applications

Typical uses. Medium-cost extrusion alloy with good mechanical properties and high elongation Used in the solution-heat-treated and artificially aged (T6) condition

Table 18 Typical and minimum tensile properties of magnesium alloy ZC71

200 29 248 36 5

Round bar with 13-125 mm (1

2-5 in.) diameter

ZCM 711-T6 (fully heat treated) 295 43 324 47 3

As-extruded

180-190

27.6

26.1-

280-290

42.1

40.6-10-13

16 mm (5

8 in.) diam bar

T5 condition 240- 34.8- 305- 44.2- 6-10

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T6 condition

340-350

50.8

49.3-

360-375

54.4

52.2-4-6

As-extruded

170-190

27.6

24.7-

255-275

40.0

37.0-12-15

T5 condition

215-235

34.1

31.2-

275-295

42.8

45.7-

340-360

52.2

Weldability. Gas-shielded arc welding with weld rod

of same base metal composition

Table 19 Minimum mechanical properties at room temperature of ZK21A-F extrusions

Tensile strength Yield strength Compressive

yield strength Form

Elongation,

%

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Rods, bars, and shapes 260 38 195 28 135 20 4

Composition limits. 3.5 to 4.5 Zn, 0.45 Zr min, 0.30

max other (total), bal Mg

Applications

Typical uses. High yield strength extrusion alloy, available in as-extruded (F) and artificially aged (T5) tempers Not as sensitive to stress concentration at thread roots as other high-strength alloys Can be heat treated Can replace ZK60A, especially for diamond drill rod, and is more readily extruded

Table 20 Minimum mechanical properties of ZK40A-T5 at room temperature

Tensile strength Yield strength Compressive

yield strength Form

AMS. Extrusions: 4352 Forgings: 4362

ASTM. Extrusions: B 107 Forgings: B 91

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Government. Extruded rod, bar, and shapes:

QQ-M-31 Extruded tubing: WW-T-825 Forgings: QQ-M-40

Foreign. Elektron ZW6 British: BS 3373 MAG161

German: DIN 9715 3.5161 French: AFNOR G-Z5Zr

Composition limits. 4.8 to 6.2 Zn, 0.45 Zr min, 0.30

max other (total), bal Mg

Applications

Typical uses. Extruded products and press forgings with high strength and good ductility; can be artificially aged to T5 temper

Table 21 Typical mechanical properties of ZK60A at room temperature

Tensile

strength

Hardness Shear

strength

Ultimate bearing strength

Bearing yield strength

HB (b) HRE MPa ksi MPa ksi MPa ksi MPa ksi

Extruded bars, rod, and shapes

Elastic modulus. Tension, 45 GPa (6.5 × 106 psi); shear, 17 GPa (2.4 × 106 psi)

Mass Characteristics

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Density. 1.83 g/cm (0.066 lb/in.) at 20 °C (68 °F)

Thermal Properties

Liquidus temperature. 635 °C (1175 °F)

Solidus temperature. 520 °C (970 °F)

Aging temperature. 150 °C (300 °F) for 24 h in the air, followed by air cooling

ASTM. Die castings: B 94

Foreign. German: DIN 1729 3.5662

Composition limits of AM60A. 5.5 to 6.5 Al, 0.13

Mn min, 0.50 Si max, 0.35 Cu max, 0.22 Zn max, 0.03

Ni max, bal Mg

Composition limits of AM60B. 5.5 to 6.5 Al, 0.25

Mn min, 0.10 Si max, 0.22 Zn max, 0.005 Fe max, 0.010

Cu max, 0.002 Ni max, 0.003 max other (total), bal Mg

If the Mn content is less than 0.25% or the Fe content in

AM60B exceeds 0.005%, then the Fe-Mn ratio will not

exceed 0.010, and corrosion resistance will rapidly

decrease

Corrosion resistance decreases with increasing Fe, Cu,

or Ni content

Applications

Typical uses. Die casting alloy used in as-cast (F) temper for production of automotive wheels and other parts requiring good elongation and toughness combined with reasonable yield and tensile properties

Tensile properties. F temper: tensile strength, 220 MPa (32 ksi); yield strength, 130 MPa (19 ksi); elongation, 6% in 50 mm (2 in.)

Compressive yield strength. F temper: 130 MPa (19 ksi)

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Coefficient of linear thermal expansion. 25.6

ASTM. Sand castings: B 80 Ingot for sand, permanent

mold, and die castings: B 93 Permanent mold castings:

Composition limits. 9.3 to 10.7 Al, 0.10 Mn min,

0.30 Zn max, 0.30 Si max, 0.10 Cu max, 0.01 Ni max,

0.30 max other (total), bal Mg

Corrosion resistance decreases with increasing amounts

of Cu, Ni, and Fe Increased amounts of Zn decrease pressure tightness More than 0.5% Si decreases elongation

Applications

Typical uses. Pressure-tight sand and permanent mold castings with good combinations of tensile strength, yield strength, and elongation

Tensile properties. See Tables 22 and 23, and Fig 8

Table 22 Typical mechanical properties of AM100A sand castings at room temperature

Tensile strength Tensile or

compressive yield strength (a)

Hardness Shear strength Temper

MPa ksi MPa ksi

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(a) Values are the same for tensile and compressive yield strengths

Table 23 Typical tensile properties of AM100A sand castings at elevated and subzero temperatures Testing temperature Tensile strength Tensile yield strength

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Fig 8 Distribution of tensile properties for separately sand cast test bars of AM100A

Hardness. At room temperature: See Table 22 At -78

°C (-108 °F): F temper, 63 HB or 75 HRE; T4 temper,

60 HB or 73 HRE; T6 temper, 85 HB or 90 HRE

Bearing properties. Ultimate bearing strength: T4

temper, 475 MPa (69 ksi); T61 temper, 560 MPa (81

ksi) Bearing yield strength: T4 temper, 310 MPa (45

ksi); T61 temper, 470 MPa (68 ksi)

Fatigue strength. R.R Moore type test At 5 × 108

cycles: F and T61 tempers, 70 MPa (10 ksi); T4 temper,

75 MPa (11 ksi)

shear, 17 GPa (2.4 × 106 psi)

Electrolytic solution potential. 1.57 V versus saturated calomel electrode

Hydrogen overvoltage. 0.27 V for extrusions; 0.06

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AS41A, AS41XB

Specifications

ASTM. Die castings: AS41A, B 94

UNS numbers. AS41A, M10410

Foreign. German: DIN 1729 3.5470

Composition limits of AS41A. 3.5 to 5.0 Al, 0.50 to

1.5 Si, 0.20 to 0.50 Mn, 0.12 Zn max, 0.06 Cu max, 0.03

Ni max, 0.30 max other (total), bal Mg

Composition limits of AS41XB. 3.5 to 5.0 Al, 0.50

to 1.50 Si, 0.35 Mn min, 0.12 Zn max, 0.0035 Fe max,

0.020 Cu max, 0.002 Ni max, bal Mg

Corrosion resistance decreases with increasing Fe, Cu,

or Ni content If the Mn content is less than 0.35% or the

Fe content in AS41XB exceeds 0.0035%, then the

Fe-Mn ratio will not exceed 0.010, and corrosion resistance

will rapidly decrease

Applications

Typical uses. Die castings used in the as-cast

condition (F temper), with creep resistance superior to

that of AZ91A, AZ91B, AZ91D, or AM60A up to 175

°C (350 °F), and with good tensile strength, tensile yield

strength, and elongation

Tensile properties. F temper: tensile strength, 210

MPa (31 ksi); yield strength, 140 MPa (20 ksi);

ASTM. Ingot: B 93 Sand Castings: B 80

Trang 38

Mn min, 0.30 Si max, 0.25 Cu max, 0.01 Ni max, 0.30

other (total), bal Mg

Excessive Si causes brittleness Excessive Cu degrades

mechanical properties and corrosion resistance

Excessive Ni degrades corrosion resistance

in 50 mm (2 in.): F and T7 tempers, 6%, T4 temper, 12%; T5 temper, 4%; T6 temper, 5% See also Fig 9

Fig 9 Distribution of tensile properties for separately cast test bars of AZ63A

Tensile properties versus temperature. See Table 24

Table 24 Typical tensile properties of AZ63A sand castings at elevated temperatures

Tested as soon as specimens reached testing temperature

Trang 40

Shear strength. F and T4 tempers, 125 MPa (18 ksi);

T5 temper, 130 MPa (19 ksi); T6 and T7 tempers, 140

MPa (20 ksi)

Compressive yield strength. F, T4, and T5

tempers, 97 MPa (14 ksi); T6 temper, 130 MPa (19 ksi);

T7 temper, 115 MPa (17 ksi)

Bearing properties. Ultimate bearing strength: F, T4,

and T6 tempers, 415 MPa (60 ksi); T5 temper, 455 MPa

(66 ksi); T7 temper, 515 MPa (75 ksi) Bearing yield

strength: F and T5 tempers, 275 MPa (40 ksi); T4

temper, 305 MPa (44 ksi); T6 temper, 360 MPa (52 ksi);

T7 temper, 325 MPa (47 ksi)

Hardness. F temper, 50 HB or 59 HRE; T4 and T5

tempers, 55 HB or 66 HRE; T6 temper, 73 HB or 83

HRE; T7 temper, 64 HB or 76 HRE

shear, 17 GPa (2.4 × 106 psi)

Impact strength. Charpy V-notch: F temper, 1.4 J

(1.0 ft · lbf); T4 temper, 3.4 J (2.5 ft · lbf); T5 temper,

3.5 J (2.6 ft · lbf); T6 temper, 1.5 J (1.1 ft · lbf)

Fatigue strength. R.R Moore type test At 5 × 108

cycles: F, T5, and T6 tempers, 76 MPa (11 ksi); T4

temper, 83 MPa (12 ksi); T7 temper, 115 MPa (17 ksi)

Thermal conductivity. 77 W/m · K (44.3 Btu/ft · h ·

°F) at 100 to 300 °C (212 to 572 °F)

Electrical Properties

Electrical conductivity. At 20 °C (68 °F): F temper, 15% IACS; T4 temper, 12.3% IACS; T5 temper, 13.8% IACS

Electrical resistivity. At 20 °C (68 °F): F temper,

ASTM. Sand castings: B 80 Ingot: B 93 Permanent

mold castings: B 199 Investment castings: B 403

Government. Sand castings: QQ-M-56 Permanent

mold castings: QQ-M-55

Foreign. Elektron A8 British: BS 2970 MAG1

German: DIN 1729 3.5812 French: AIR 3380 G-A9

Mn min, 0.30 Si max, 0.10 Cu max, 0.01 Ni max, 0.30 max other (total), bal Mg

Excessive Si causes brittleness Excessive Cu degrades mechanical properties and corrosion resistance Excessive Ni degrades corrosion resistance

Applications

Typical uses. Sand and permanent mold castings used

in the solution-treated condition (T4 temper), with good

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