Alloy 6061 aluminum

 

6061 Alloy aluminum introduction

Alloy 6061 is one of the most widely used alloys in the 6000 Series. This standard structural alloy, one of the most versatile of the heat-treatable alloys, is popular for medium to high strength requirements and has good toughness characteristics. Applications range from transportation components to machinery and equipment applications to recreation products and custom durables.  6061 Alloy can be produced for use in standard and custom shapes, rod and bard products, and seamless and structural pipe and tube.

 

Aluminium alloy 6061 is a medium to high strength heat-treatable alloy with strength higher than 6005A. It has very good corrosion resistance and very good weldability although reduced strength in the weld zone. It has medium fatigue strength. It has good cold formability in the temper T4, but limited formability in T6 temper. Not suitable for very complex cross sections.

 

Alloy 6061 has excellent corrosion resistance to atmospheric conditions and good corrosion resistance to sea water. This alloy also offers good finishing characteristics and responds well to anodizing; however, where cosmetic appearance is critical, consider the use of alloy 6063. The most common anodizing methods include clear, clear and color dye and hardcoat.

 

Alloy 6061 is easily welded and joined by various commercial methods. Since 6061 is a heat-treatable alloy, strength in its T6 condition can be reduced in the weld region. Selection of an appropriate filler alloy will depend on the desired weld characteristics.

 

Applications of Alloy 6061
Alloy 6061 is typically used for heavy duty structures in:
~ Rail coaches
~ Truck frames
~ Ship building
~ Bridges and Military bridges
~ Aerospace applications including helicopter rotor skins
~ Tube
~ Pylons and Towers
~ Transport
~ Boilermaking
~ Motorboats
~ Rivets

Temper Types

The most common temper for 6061 aluminium is:

T6 - Solution heat treated and artificially aged

Supplied Forms

Alloy 6061 is typically supplied as

Extrusions

 

Typical Processing Conditions of alloy 6061

Preheating

Billet should be preheated to a temperature in the region of 480°C to ensure good extrudability and mechanical properties. Difficult sections, such as thin walled extrusions or hollows may require higher billet preheat (~500°C).  
      
Extrusion Conditions

The temperature of the container should be set at least 30°C below the billet temperature to ensure that the billet skin is retained in the butt. The billet preheat temperature and extrusion speed should be controlled so that the exit temperature is maintained in the range of 520°C to 570°C. Typical extrusion speeds for this alloy are in the range of 10 to 25 m/min for solid profiles and 5 to 10 m/min for hollow profiles  
      
Press Quenching

The cooling rate of the extrudate from exit temperature down to 250°C should be in excess of 300°C/min to achieve minimum mechanical properties. For thin sections (less than 6mm), a mist quench may be adequate to achieve this cooling rate. For thicker sections (6 to 10mm), vigorous water quenching is required to achieve the minimum cooling rate. The quench equipment should be located as close as possible to the exit from the press to minimize temperature loss from the extrudate prior to the quench.  
      
Straightening

Stretching to an elongation of 0.5% is recommended for straightening while stretching beyond 1% elongation may result in orange peel finish on the extrudate.  
      
Ageing Treatment

Various ageing times and temperatures can be used to obtain good mechanical properties. However the ageing conditions generally recommended for 6061 alloys for production operations are 6 hours at 185 +/- 5°C.  

 

6061 Alloy aluminum extrusion supplier, Foshan Honstar Aluminum Products Co., Ltd