Aluminum Production and Properties

Resistance Welding

Lesson ObjectivesWhen you finish this lesson you will understand:•

Learning Activities1. View Slides; 2. Read Notes, 3. Listen to lecture4. Do on-line workbook

Keywords

Carbon Anode

AluminumCathode

BauxiteAlumina

plusFluoride salts

CO2OAl

Hall- Heroult Process

Pxxyyxx = % Si Impurityyy = % Fe Impurity

Grades Range From:P0202 to P1535

Typical Grade: P10200.10% Si & 0.20% Fe

Additional ElectrolyticRefining Available to get99.999% Purity

Facility for producing aluminum sheet re-rolled directly from molten aluminum

Metals Handbook vol 2, ASM

AWS Welding Handbook

Chemical Composition of Aluminum Alloys

[Reference: Resistance Welding Manual, p.11-2, RWMA]

Classification of Aluminum Alloys

• Heat-Treatable Alloys– Can obtain increased strength

levels through precipitation hardening

– Typical hardening additions include copper, magnesium, zinc and silicon

– These additions show increasing solid solubility with increasing temperature

– Alloys of this type include the 2000, 6000 and 7000 series

• Non-Heat-Treatable Alloys– Strengthened by work-

hardening and solid solution strengthening

– Elements such as manganese, silicon, iron and magnesium are typical solid-solution hardening agents

– Alloys of this type include the 1000, 3000, 4000 and 5000 series

Some Applications of Aluminum Alloys

• Heat-Treatable Alloys– 2014 Hydraulic fittings for

aircraft and automotive

– 2036 6009 Automotive Body

– 2219 tanks

– 6061 Structural

– 6101 Electrical Conductors

– 7075 High Strength Aircraft

• Non-Heat-Treatable Alloys– 1060 Chem Processing Tanks

– 1100 Architectural

– 3003 General Purpose, Tanks

– 5052 Sheet Applications

Non-Heat Treatable AlloysTemper Designations

Designation Description ApplicationO Annealed,

RecrystalizedLowest Strength, High ductility

F As Fabricated Fabrication with no special control over thermal or strainhardening

H1 Strain Hardened Strain hardened without subsequent annealH2 Strain Hardened

& AnnealedStrain hardened more than the desired amount and then

partially annealed to strengthH3 Strain Hardened

& StabilizedStrain hardened and low temp stabilization treatment to prevent

age softening

Heat Treatable AlloysTemper Designations

Designation Description ApplicationO Annealed,

RecrystalizedLowest Strength, High ductility

F As Fabricated Fabrication with no special control over thermal or strainhardening

W Solution HeatTreatment

Unstable temper application with subsequent period of naturalage

T1 Cooled and naturally agedT2 Cooled, cold worked & Naturally agedT3 Solution heat treated, cold worked & naturally agedT4 Solution heat treated & naturally agedT5 Cooled and artificially agedT6 Solution heat treated and StabilizedT7 Solution heat treated, stabilized to provide special propertyT8 Solution heat treated, cold worked, artificially agedT9 Solution heat treated, artificially aged, then cold worked

T10 Cooled, cold worked, then artificially aged

For a more extensive description see the table in AWS Welding Handbook, Vol 3, 8 th Ed. Page 9

Employing These VariousTreatments Can ProduceAluminum Alloys With AWide Range of MechanicalProperties As Observed inThe Following Tables

Mechanical Properties of Some Aluminum Alloys

[Reference: Resistance Welding Manual, p.11-12, RWMA]

Mechanical Properties of Some Aluminum Alloys (CONT.)

[Reference: Resistance Welding Manual, p.11-12, RWMA]

Effect of Temperature on Mechanical Properties of Aluminum Alloys

[Reference: Resistance Welding Manual, p.11-13, RWMA]

Effect of Temperature on Mechanical Properties of Aluminum Alloys (CONT.)

[Reference: Resistance Welding Manual, p.11-13, RWMA]

Effect of Temperature on Mechanical Properties of Aluminum Alloys (CONT.)

[Reference: Resistance Welding Manual, p.11-14, RWMA]

Mechanical and Physical Properties of Some Automotive Alloys

[Reference: Guidelines to Resistance Spot Welding Aluminum Automotive Sheet, p.4, The Aluminum Association]